Document:

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                                                                    Exhibit 4.28

                       FOCAL COMMUNICATIONS CORPORATION

                                  $275,000,000

                         11.875% SENIOR NOTES DUE 2010

                                 _____________

                                   INDENTURE

                         Dated as of January 12, 2000

                                 _____________

                         HARRIS TRUST AND SAVINGS BANK,

                                    Trustee

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                             CROSS-REFERENCE TABLE

          Reconciliation and tie between the Trust Indenture Act of 1939, as
amended, and the Indenture, dated as of January 12, 2000

<TABLE>
<CAPTION>
Trust Indenture                         Indenture
  Act Section                            Section
---------------                         ---------
<S>                                     <C>
(S)310(a)(1)..........................  7.10
(a)(2)................................  7.10
(a)(3)................................  N.A.
(a)(4)................................  N.A.
(a)(5)................................  7.10
(b)...................................  7.08; 7.10
(c)...................................  N.A.
(S)311(a).............................  7.11
(b)...................................  7.11
(c)...................................  N.A.
(S)312(a).............................  7.06(a); 7.06(b)
(b)...................................  7.06(c)
(c)...................................  7.06(d)
(S)313(a).............................  7.06(e)
(b)...................................  7.06(f)
(c)...................................  7.06(e), 7.06(f)
(d)...................................  7.06(g)
(S)314(a).............................  4.18; 4.19
(b)...................................  4.18(b)
(c)(1)................................  10.03
(c)(2)................................  10.03
(c)(3)................................  N.A.
(d)...................................  N.A.
(e)...................................  10.04
(f)...................................  4.19
(S)315(a).............................  7.01(b)
(b)...................................  7.05
(c)...................................  7.01(c)
(e)...................................  6.10
(S)316(a).............................  2.10(c)
(a)(1)(A).............................  6.05
(a)(1)(B).............................  6.04
(a)(2)................................  N.A.
(b)...................................  6.07
(c)...................................  9.05
(S)317(a)(1)..........................  6.03(b)
(a)(2)................................  6.08
(b)...................................  2.07(b)
(S)318(a).............................  10.01
</TABLE>
_________________
Note:  This reconciliation and tie shall not, for any purpose, be deemed to be a
       part of the Indenture.

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                               TABLE OF CONTENTS
<TABLE>
<CAPTION>

                                                                           Page
<S>                                                                        <C>

ARTICLE I   Definitions and Other Provisions of General Application.........  1
        SECTION 1.01.  Definitions..........................................  1
        SECTION 1.02.  Incorporation by Reference of Trust Indenture Act.... 20
        SECTION 1.03.  Rules of Construction................................ 20
        SECTION 1.04.  Form of Documents Delivered to Trustee............... 21
        SECTION 1.05.  Acts of Holders...................................... 21
        SECTION 1.06.  Satisfaction and Discharge........................... 22

ARTICLE II  The Notes....................................................... 22
        SECTION 2.01.  Form and Dating...................................... 22
        SECTION 2.02.  Form of Face of Note................................. 23
        SECTION 2.03.  Form of Reverse of Note.............................. 27
        SECTION 2.04.  Form of Trustee's Certificate of Authentication...... 38
        SECTION 2.05.  Execution and Authentication......................... 38
        SECTION 2.06.  Note Registrar and Paying Agent...................... 39
        SECTION 2.07.  Paying Agent To Hold Money in Trust.................. 40
        SECTION 2.08.  Registration, Registration of Transfer and Exchange.. 40
        SECTION 2.09.  Replacement Notes.................................... 45
        SECTION 2.10.  Outstanding Notes.................................... 46
        SECTION 2.11.  Temporary Notes...................................... 46
        SECTION 2.12.  Cancellation......................................... 47
        SECTION 2.13.  Payment of Interest; Interest Rights Preserved....... 47
        SECTION 2.14.  Authorized Denominations............................. 48
        SECTION 2.15.  Computation of Interest.............................. 48
        SECTION 2.16.  Persons Deemed Owners................................ 48
        SECTION 2.17.  CUSIP Numbers........................................ 48
        SECTION 2.18.  Holder Lists......................................... 48

ARTICLE III Redemption...................................................... 49
        SECTION 3.01.  Notice to Trustee.................................... 49
        SECTION 3.02.  Selection of Notes To Be Redeemed.................... 49
        SECTION 3.03.  Notice of Redemption................................. 49
        SECTION 3.04.  Effect of Notice of Redemption....................... 50
        SECTION 3.05.  Deposit of Redemption Price.......................... 50
        SECTION 3.06.  Notes Redeemed in Part............................... 50

ARTICLE IV  Covenants....................................................... 51
        SECTION 4.01.  Payment of Notes..................................... 51
        SECTION 4.02.  Maintenance of Office or Agency...................... 51
        SECTION 4.03.  Money for the Note Payments To Be Held in Trust...... 51
        SECTION 4.04.  Corporate Existence.................................. 52
        SECTION 4.05.  Maintenance of Property.............................. 52
        SECTION 4.06.  Payment of Taxes and Other Claims.................... 52
        SECTION 4.07.  Repurchase at the Option of Holders upon a Change of
                         Control............................................ 52
        SECTION 4.08.  Limitation on Asset Sales............................ 55
        SECTION 4.09.  Limitation on Consolidated Indebtedness.............. 59
        SECTION 4.10.  Reserved............................................. 61
</TABLE>

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<TABLE>
<CAPTION>
                                                                           Page
<S>                                                                        <C>
        SECTION 4.11.  Limitation on Restricted Payments...................  62
        SECTION 4.12.  Limitation on Liens.................................  64
        SECTION 4.13.  Limitation on Sale and Leaseback Transactions.......  65
        SECTION 4.14.  Limitation on Dividends and Other Payment
                         Restrictions Affecting Subsidiaries...............  65
        SECTION 4.15.  Limitation on Issuance and Sale of Capital Stock of
                         Restricted Subsidiaries...........................  66
        SECTION 4.16.  Transactions with Affiliates........................  67
        SECTION 4.17.  Restricted and Unrestricted Subsidiaries............  68
        SECTION 4.18.  Reports.............................................  68
        SECTION 4.19.  Statement of Compliance; Notice of Default or Event
                         of Default........................................  69

ARTICLE V   Amalgamation, Consolidation, Merger, Conveyance, Lease or
              Transfer.....................................................  69
        SECTION 5.01.  Merger, Consolidation or Sale of Assets.............  69
        SECTION 5.02.  Successor Corporation Substituted...................  70

ARTICLE VI  Defaults and Remedies..........................................  70
        SECTION 6.01.  Events of Default...................................  70
        SECTION 6.02.  Acceleration........................................  72
        SECTION 6.03.  Other Remedies......................................  73
        SECTION 6.04.  Waiver of Past Defaults.............................  73
        SECTION 6.05.  Control by Majority.................................  74
        SECTION 6.06.  Limitation on Suits.................................  74
        SECTION 6.07.  Rights of Holders To Receive Payment................  75
        SECTION 6.08.  Trustee May File Proofs of Claim....................  75
        SECTION 6.09.  Priorities..........................................  75
        SECTION 6.10.  Undertaking for Costs...............................  76
        SECTION 6.11.  Waiver of Stay or Extension Laws....................  76
        SECTION 6.12.  Trustee May Enforce Claims Without Possession
                         of the Notes......................................  76
        SECTION 6.13.  Restoration of Rights and Remedies..................  76
        SECTION 6.14.  Rights and Remedies Cumulative......................  77
        SECTION 6.15.  Delay or Omission Not Waiver........................  77

ARTICLE VII Trustee........................................................  77
        SECTION 7.01.  Duties of Trustee...................................  77
        SECTION 7.02.  Rights of Trustee...................................  78
        SECTION 7.03.  Individual Rights of Trustee........................  79
        SECTION 7.04.  Trustee's Disclaimer................................  79
        SECTION 7.05.  Notice of Defaults..................................  79
        SECTION 7.06.  Preservation of Information; Reports by Trustee to
                         Holders...........................................  79
        SECTION 7.07.  Compensation and Indemnity..........................  80
        SECTION 7.08.  Replacement of Trustee..............................  81
        SECTION 7.09.  Successor Trustee by Merger.........................  83
        SECTION 7.10.  Eligibility; Disqualification.......................  83
        SECTION 7.11.  Preferential Collection of Claims Against Company...  84
</TABLE>

                                      ii
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<TABLE>
<CAPTION>
                                                                           Page
<S>                                                                        <C>
ARTICLE VIII  Defeasance...................................................  84
        SECTION 8.01.  Company's Option To Effect Legal Defeasance or
                         Covenant Defeasance...............................  84
        SECTION 8.02.  Legal Defeasance and Discharge......................  84
        SECTION 8.03.  Covenant Defeasance.................................  85
        SECTION 8.04.  Conditions to Defeasance or Covenant Defeasance.....  85
        SECTION 8.05.  Deposited United States Dollars and U.S. Government
                         Obligations To Be Held in Trust; Miscellaneous
                         Provisions........................................  86
        SECTION 8.06.  Reinstatement.......................................  87

ARTICLE IX    Amendments...................................................  87
        SECTION 9.01.  Without Consent of Holders..........................  87
        SECTION 9.02.  With Consent of Holders.............................  88
        SECTION 9.03.  Effect of Supplemental Indentures...................  89
        SECTION 9.04.  Compliance with Trust Indenture Act.................  89
        SECTION 9.05.  Revocation and Effect of Consents and Waivers.......  89
        SECTION 9.06.  Notation on or Exchange of Notes....................  89
        SECTION 9.07.  Trustee To Execute Supplemental Indentures..........  90

ARTICLE X     Miscellaneous................................................  90
        SECTION 10.01.  Trust Indenture Act Controls.......................  90
        SECTION 10.02.  Notices............................................  90
        SECTION 10.03.  Certificate and Opinion as to Conditions Precedent.  90
        SECTION 10.04.  Statements Required in Certificate  or Opinion.....  91
        SECTION 10.05.  Rules by Trustee, Paying Agent and  Note Registrar.  91
        SECTION 10.06.  Payments on Business Days..........................  91
        SECTION 10.07.  Governing Law; Jurisdiction........................  91
        SECTION 10.08.  No Recourse Against Others.........................  91
        SECTION 10.09.  Successors.........................................  91
        SECTION 10.10.  Counterparts.......................................  91
        SECTION 10.11.  Table of Contents; Headings........................  92
        SECTION 10.12.  Severability.......................................  92
        SECTION 10.13.  Further Instruments and Acts.......................  92

</TABLE>

ANNEX A FORM OF REGULATION S CERTIFICATE
ANNEX B FORM OF RESTRICTED SECURITIES CERTIFICATE
ANNEX C FORM OF UNRESTRICTED SECURITIES CERTIFICATE
ANNEX D FORM OF CLEARING SYSTEM CERTIFICATE
ANNEX E FORM OF CERTIFICATE OF BENEFICIAL OWNERSHIP

                                      iii
<PAGE>

INDENTURE, dated as of January   , 2000, between FOCAL COMMUNICATIONS
CORPORATION ("Company"), a Delaware corporation having its principal office at
200 N. LaSalle, Chicago, Illinois 60601, and Harris Trust and Savings Bank, an
Illinois banking corporation, as trustee hereunder (the "Trustee"), having its
corporate trust office at 311 West Monroe Street, Chicago, Illinois 60606.

                                    RECITALS

     WHEREAS, the Company has duly authorized the issuance of $275,000,000
aggregate principal amount of its 11.875% Senior Notes due 2010 ("Notes") of
substantially the tenor and amount hereinafter set forth, and to provide
therefor the Company has duly authorized the execution and delivery of this
Indenture.

     WHEREAS, all things necessary to make the Notes, when executed by the
Company and authenticated and delivered by the Trustee hereunder, duly issued by
the Company, the valid obligations of the Company, and to make this Indenture
(as defined herein) a valid instrument of the Company, in accordance with its
terms, have been done.

     NOW, THEREFORE, THIS INDENTURE WITNESSETH, that, for and in consideration
of the premises and the purchase of the Notes by the Holders (as defined herein)
thereof, it is mutually covenanted and agreed, for the equal and proportionate
benefit of all Holders of the Notes, as follows:

                                   ARTICLE I

            Definitions and Other Provisions of General Application

     SECTION 1.0  Definitions.  For all purposes of this Indenture, except as
otherwise expressly provided or unless the context otherwise requires:

          (a)  the terms defined in this Article I have the meanings assigned to
     them in this Article I, and include the plural as well as the singular; and

          (b)  all accounting terms not otherwise defined herein have the
     meanings assigned to them in accordance with GAAP.

     "Acquired Indebtedness" means, with respect to any specified Person,
Indebtedness of any other Person existing at the time such other Person merged
with or into or became a Subsidiary of such specified Person; provided that such
Indebtedness was not incurred in connection with, or in anticipation or
contemplation of, such other Person merging with or into or becoming a
Subsidiary of such specified Person, but excluding Indebtedness which is
extinguished, retired or repaid in connection with such other Person merging
with or into or becoming a Subsidiary of such specified Person.

     "Act" when used with respect to any Holder, has the meaning set forth in
Section 1.05(a).

<PAGE>

     "Additional Interest" has the meaning set forth in the form of Note
contained in Section 2.03.

     "Additional Interest Payment Date" has the meaning set forth in Section
2.13.

     "Affiliate" means, as to any Person, any other Person which directly or
indirectly controls, or is under common control with, or is controlled by, such
Person; provided that each Unrestricted Subsidiary shall be deemed to be an
Affiliate of the Company and of each other Subsidiary of the Company; provided
further that neither the Company nor any of its Restricted Subsidiaries shall be
deemed to be Affiliates of each other. For purposes of this definition,
"control" (including, with correlative meanings, the terms "controlling," "under
common control with" and "controlled by"), as used with respect to any Person,
shall mean the possession, directly or indirectly, of the power to direct or
cause the direction of the management or policies of such Person, whether
through the ownership of Voting Stock, by agreement or otherwise.

     "Affiliate Transaction" has the meaning set forth in Section 4.16.

     "Agent Member" means any member of, or participant in, the Depositary.

     "Applicable Procedures" means, with respect to any transfer or transaction
involving a Global Note or beneficial interest therein, the rules and procedures
of the Depositary for such Note, Euroclear and Cedel, in each case to the extent
applicable to such transaction and as in effect from time to time.

     "Asset Sale" means any transfer, conveyance, sale, lease or other
disposition by the Company or any of its Restricted Subsidiaries (including an
amalgamation, consolidation or merger or other sale of any such Restricted
Subsidiary with, into or to any Person (other than the Company or any other
Restricted Subsidiary) in a transaction in which such Restricted Subsidiary
ceases to be a Restricted Subsidiary, but excluding a disposition by a
Restricted Subsidiary to the Company or a Significant Restricted Subsidiary or
by the Company to a Significant Restricted Subsidiary) of (i) shares of Capital
Stock or other ownership interests of a Subsidiary of the Company (other than as
permitted by Section 4.15 or pursuant to an amalgamation, merger or
consolidation of a Restricted Subsidiary into the Company or any Restricted
Subsidiary), (ii) substantially all of the assets of the Company or any
Restricted Subsidiary representing a division or line of business (other than as
part of a Permitted Investment) or (iii) other assets or rights of the Company
or any of its Restricted Subsidiaries outside of the ordinary course of business
and, in each case, that is not governed by Article V of this Indenture; provided
that "Asset Sale" shall not include (i) sales or other dispositions of
inventory, receivables and other current assets in the ordinary course of
business or sales or other dispositions of equipment that has become worn-out,
obsolete or damaged or otherwise unsuitable for use in connection with the
business of the Company or a Restricted Subsidiary, (ii) contemporaneous
exchanges by the Company or any Restricted Subsidiary of Telecommunications
Assets for other Telecommunications Assets in the ordinary course of business;
provided that the applicable Telecommunications Assets received by the Company
or such Restricted Subsidiary have at least substantially equal Fair Market
Value to the Company or such Restricted Subsidiary (as evidenced by a Board
Resolution), and (iii) the sale or other disposition of any assets (a) with a
Fair Market Value (as certified in an Officers' Certificate) not in excess of
$1,000,000 or (b) that constitute Restricted Payments which are permitted under
Section 4.11.

                                       2
<PAGE>

     "Asset Sale Offer" has the meaning set forth in Section 4.08(c).

     "Asset Sale Payment Date" has the meaning set forth in Section 4.08(d)(ii).

     "Attributable Indebtedness" means, with respect to any Sale and Leaseback
Transaction of any Person, as at the time of determination, the greater of (i)
the capitalized amount in respect of such transaction that would appear on the
balance sheet of such Person in accordance with GAAP and (ii) the present value
(discounted at a rate consistent with accounting guidelines, as determined in
good faith by the responsible accounting officer of such Person) of the payments
during the remaining term of the lease (including any period for which such
lease has been extended or may, at the option of the lessor, be extended) or
until the earliest date on which the lessee may terminate such lease without
penalty or upon payment of a penalty (in which case the payments during the
remaining term shall include such penalty).

     "Average Life" means, as of any date, with respect to any debt security or
Disqualified Stock, the quotient obtained by dividing (i) the sum of the
products of (a) the number of years from such date to the dates of each
scheduled principal payment or redemption payment (including any sinking fund or
mandatory redemption payment requirements) of such debt security or Disqualified
Stock multiplied in each case by (b) the amount of such principal or redemption
payment, by (ii) the sum of all such principal or redemption payments.

     "Bankruptcy Law" has the meaning set forth in Section 6.01(f).

     "Board of Directors" means the Board of Directors of the Company or any
committee thereof duly authorized to act on behalf of the Board of Directors.

     "Board Resolution" means a copy of a resolution, certified by the Secretary
of the Company to have been a duly adopted resolution of the Board of Directors
and to be in full force and effect on the date of such certification, and
delivered to the Trustee within 60 days of adoption thereof.

     "Business Day" means each Monday, Tuesday, Wednesday, Thursday and Friday
that is not a day on which banking institutions in the City of New York, New
York or in the City of Chicago, Illinois are authorized or obligated by law,
executive order or regulation to close.

     "Capital Lease Obligation" of any Person means the obligation to pay rent
or other payment amounts under a lease of (or other Indebtedness arrangement
conveying the right to use) real or personal Property which is required to be
classified and accounted for as a capital lease or a liability on the face of a
balance sheet of such Person prepared in accordance with GAAP, and the maturity
thereof shall be the date of the last payment of rent or any amount due under
such lease prior to the first date upon which such lease may be terminated by
the lessee without payment of a penalty. The principal amount of such obligation
shall be the capitalized amount that would appear on the face of a balance sheet
of such Person in accordance with GAAP.

     "Capital Stock" in any Person means any and all shares, interests,
participation or other equivalents of an equity interest (however designated) in
such

                                       3
<PAGE>

Person and any rights (other than Indebtedness convertible into an equity
interest), warrants or options to subscribe for or acquire an equity interest in
such Person.

     "Cash Proceeds" means, with respect to any Asset Sale by any Person, the
aggregate consideration received in respect of such sale by such Person in the
form of cash and Eligible Cash Equivalents.

     "Cedel" means Cedel Bank, S.A. (or any successor securities clearing
agency).

     "Change of Control" shall be deemed to occur if (i) the sale, conveyance,
transfer or lease of all or substantially all of the assets of the Company to
any "Person" or "group" (as such term is used in Sections 13(d)(3) and 14(d)(2)
of the Exchange Act, including any group acting for the purpose of acquiring,
holding or disposing of securities within the meaning of Rule 13d-5(b)(i) under
the Exchange Act), other than any Permitted Holder or any Restricted Subsidiary,
shall have occurred, (ii) any "Person" or "group" (as such term is used in
Sections 13(d)(3) and 14(d)(2) of the Exchange Act including any group acting
for the purpose of acquiring, holding or disposing of securities within the
meaning of Rule 13d-5(b)(i) under the Exchange Act), other than any Permitted
Holder, becomes the "beneficial owner" (as defined in Rule 13d-3 under the
Exchange Act) of more than 50% of the total voting power of all classes of the
Voting Stock of the Company (including any warrants, options or rights to
acquire such Voting Stock), calculated on a fully diluted basis, (iii) at any
time after a Public Market shall exist, during any period of two consecutive
years, individuals who at the beginning of such period constituted the Board of
Directors (together with (a) any directors whose election or appointment by the
Board of Directors or whose nomination for election by the stockholders of the
Company was approved by a vote of a majority of the directors then still in
office who were either directors at the beginning of such period or whose
election or nomination for election was previously so approved and (b) any
directors elected pursuant to the terms of any shareholders' agreement among the
Company's shareholders) cease for any reason to constitute a majority of the
Board of Directors then in office or (iv) the merger, amalgamation or
consolidation of the Company with or into another Person or the merger of
another Person with or into the Company shall have occurred, and the securities
of the Company that are outstanding immediately prior to such transaction and
which represent 100% of the aggregate voting power of the Voting Stock of the
Company are changed into or exchanged for cash, securities or property, unless
pursuant to such transaction such securities are changed into or exchanged for,
in addition to any other consideration, securities of the surviving corporation
that represent immediately after giving effect to such transaction, at least a
majority of the aggregate voting power of the Voting Stock of the surviving
corporation.

     "Change of Control Offer" has the meaning set forth in Section 4.07(a).

     "Change of Control Payment Date" has the meaning set forth in Section
4.07(b)(ii).

     "Change of Control Purchase Price" has the meaning set forth in Section
4.07(a).

     "Change of Control Redemption" has the meaning set forth in Section
4.07(e).

                                       4
<PAGE>

     "Change of Control Redemption Date" has the meaning set forth in Section
4.07(e).

     "Change of Control Redemption Purchase Price" has the meaning set forth in
Section 4.07(e).

     "clearing agency" has the meaning set forth in Section 3(a)(23) of the
Exchange Act.

     "Commission" means the United States Securities and Exchange Commission, as
from time to time constituted, created under the Exchange Act, or, if at any
time after the execution of this Indenture such commission is not existing and
performing the duties now assigned to it under the Trust Indenture Act, the body
performing such duties at such time.

     "Common Stock" means, with respect to the Company, the Common Stock, $.01
par value, of the Company.

     "Company" means the party named as such in the preamble to this Indenture
until a successor replaces it pursuant to the applicable provisions hereof and,
thereafter, means such successor.

     "Company Order" means a written order signed in the name of the Company by
(i) its Chairman of the Board, President, Executive Vice President, Chief
Financial Officer or a Vice Chairman and (ii) a Vice President, its Treasurer,
an Assistant Treasurer, its Corporate Secretary or an Assistant Secretary.

     "Consolidated Cash Flow Available for Fixed Charges" for any period means
the Consolidated Net Income of the Company and its Restricted Subsidiaries for
such period increased, to the extent deducted in arriving at Consolidated Net
Income, by the sum of (i) Consolidated Interest Expense of the Company and its
Restricted Subsidiaries for such period, (ii) Consolidated Income Tax Expense of
the Company and its Restricted Subsidiaries for such period, (iii) the
consolidated depreciation and amortization expense of the Company and its
Restricted Subsidiaries for such period, (iv) any non-cash expense related to
the issuance to employees of the Company or any Restricted Subsidiary of options
to purchase Capital Stock of the Company or such Restricted Subsidiary, (v) any
charge related to any premium or penalty paid in connection with redeeming or
retiring any Indebtedness prior to its stated maturity and (vi) any non-cash
expense related to a purchase accounting adjustment not requiring an accrual or
reserve and separately disclosed in the Company's consolidated statement of
operations and deficit, and decreased by the amount of any non-cash item that
increases such Consolidated Net Income, all as determined on a consolidated
basis in accordance with GAAP; provided that (a) there shall be excluded from
the Consolidated Cash Flow Available for Fixed Charges (if positive) of any
Restricted Subsidiary (calculated separately for such Restricted Subsidiary in
the same manner as provided above for the Company) that is subject to a
restriction which prevents the payment of dividends or the making of
distributions to the Company or another Restricted Subsidiary to the extent of
such restriction and (b) (1) if, during or after such period, the Company or any
of its Restricted Subsidiaries shall have made any disposition of any Person or
business, then Consolidated Cash Flow Available for Fixed Charges of the Company
and its Restricted Subsidiaries shall be computed so as to give pro forma effect
to such disposition and (2) if, during or after such period, the Company or any
of its Restricted Subsidiaries

                                       5
<PAGE>

completes an acquisition of any Person or business which immediately after such
acquisition is a Subsidiary of such Person or whose assets are held directly by
the Company or a Restricted Subsidiary, then Consolidated Cash Flow Available
for Fixed Charges shall be computed so as to give pro forma effect to the
acquisition of such Person or business.

     "Consolidated Income Tax Expense" for any period means the aggregate amount
of the provisions for income taxes of the Company and its Restricted
Subsidiaries for such period calculated on a consolidated basis in accordance
with GAAP.

     "Consolidated Interest Expense" means for any period the interest expense
included in a consolidated income statement (excluding interest income) of the
Company and its Restricted Subsidiaries for such period in accordance with GAAP,
including without limitation or duplication (or, to the extent not so included,
with the addition of), (i) the amortization of Indebtedness discount (including
original issue discount), (ii) any payments or fees with respect to letters of
credit, bankers' acceptances or similar facilities, (iii) fees with respect to
interest rate swap or similar agreements or foreign currency hedge, exchange or
similar agreements, (iv) Preferred Stock dividends of Restricted Subsidiaries
(other than dividends paid in shares of Preferred Stock that is not Disqualified
Stock) declared and paid or payable, (v) accrued Disqualified Stock dividends of
the Company and its Restricted Subsidiaries, whether or not declared or paid,
(vi) interest on Indebtedness guaranteed by the Company and its Restricted
Subsidiaries, (vii) the portion of any Capital Lease Obligation accruing during
such period that is allocable to interest expense in accordance with GAAP,
(viii) capitalized interest and (ix) commitment and other fees with respect to
senior credit facilities.

     "Consolidated Net Income" of the Company means, for any period, the
aggregate net income (or net loss) of the Company and its Restricted
Subsidiaries for such period on a consolidated basis determined in accordance
with GAAP; provided that there shall be excluded therefrom, without duplication
(i) all items classified as extraordinary or non-recurring, (ii) any net income
(or net loss) of any Person other than the Company and its Restricted
Subsidiaries, except to the extent of the amount of dividends or other
distributions actually paid to the Company or its Restricted Subsidiaries by
such other Person during such period, (iii) the net income (or net loss) of any
Person acquired by the Company or any of its Restricted Subsidiaries in a
pooling-of-interests transaction for any period prior to the date of the related
acquisition, (iv) any gain or loss, net of taxes, realized on the termination of
any employee pension benefit plan, (v) net gains (or net losses) in respect of
Asset Sales by the Company or its Restricted Subsidiaries, (vi) the net income
(or net loss) of any Restricted Subsidiary to the extent that the payment of
dividends or other distributions to the Company is restricted by the terms of
its constituting documents or any agreement, instrument, contract, judgment,
order, decree, statute, rule, governmental regulation or otherwise, except for
any dividends or distributions actually paid by such Restricted Subsidiary to
the Company, (vii) with regard to a non-wholly owned Restricted Subsidiary, any
aggregate net income (or net loss) in excess of the Company's or such Restricted
Subsidiary's pro rata share of such non-wholly owned Restricted Subsidiary's net
income (or net loss) and (viii) the cumulative effect of changes in accounting
principles.

     "Consolidated Net Worth" means, at any date of determination, stockholders'
equity as set forth on the most recently available quarterly or annual
consolidated balance sheet of the Company and its Restricted Subsidiaries (which
shall be as of a date not more than 90 days prior to the date of such
computation, and which shall

                                       6
<PAGE>

not take account of Unrestricted Subsidiaries), less any amounts attributable to
Disqualified Stock or any equity security convertible into or exchangeable for
Indebtedness, the cost of treasury stock and the principal amount of any
promissory notes receivable from the sale of the Capital Stock of the Company or
any of its Restricted Subsidiaries, each item to be determined in conformity
with GAAP.

     "Consolidated Tangible Assets" of any Person means the total amount of
assets (less applicable reserves and other properly deductible items) which
under GAAP would be included on a consolidated balance sheet of such Person and
its Restricted Subsidiaries after deducting therefrom all goodwill, trade names,
trademarks, patents, unamortized debt discount and expense and other like
intangibles, which in each case under GAAP would be included on such
consolidated balance sheet.

     "Corporate Trust Office" means the principal office of the Trustee in the
City of Chicago, Illinois where at any particular time its corporate trust
business shall be principally administered, which at the date hereof is located
at 311 West Monroe Street, Chicago, Illinois 60606.

     Covenant Defeasance" has the meaning set forth in Section 8.0.

     "Default" means any event, act or condition, the occurrence of which is, or
after notice or the passage of time or both would be, an Event of Default.

     "Defaulted Interest" has the meaning set forth in Section 2.13(b).

     "Defeasance" has the meaning set forth in Section 8.02(a).

     "Depositary" means, with respect to the Notes issuable or issued in whole
or in part in the form of one or more Global Notes, The Depository Trust Company
for so long as it shall be a clearing agency registered under the Exchange Act,
or such successor as the Company shall designate from time to time in an
Officers' Certificate delivered to the Trustee.

     "Disqualified Stock" means any Capital Stock which, by its terms (or by the
terms of any security into which it is convertible or for which it is
exchangeable), or upon the happening of any event, or otherwise, matures or is
mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or
is redeemable at the option of the holder thereof, or is exchangeable for
Indebtedness by the holder thereof at any time, in whole or in part, on or prior
to the Stated Maturity of the Notes.

     "Duff & Phelps" means Duff & Phelps Credit Rating Co., or, if Duff & Phelps
Credit Rating Co. shall cease rating the specified debt securities and such
ratings business with respect thereto shall have been transferred to a successor
Person, such successor Person; provided that if Duff & Phelps Credit Rating Co.
ceases rating the specified debt securities and its rating business with respect
thereto shall not have been transferred to any successor Person or such
successor Person is Standard & Poor's or Moody's, then "Duff & Phelps" shall
mean any other "nationally recognized statistical rating organization" (as
defined in Rule 436 under the Securities Act) (other than Standard & Poor's or
Moody's, as applicable, if either is such successor Person) that rates the
specified debt securities and that shall have been designated by the Company in
an Officers' Certificate.

                                       7
<PAGE>

     "Eligible Cash Equivalents" means any of the following: (i) any investment
in direct obligations of the United States of America or any agency thereof or
obligations guaranteed by the United States of America or any agency thereof, in
each case with a term of not more than one year, (ii) investments in time
deposit accounts, term deposit accounts, certificates of deposit, money-market
deposits, bankers' acceptances and obligations maturing within one year of the
date of acquisition thereof issued by a bank or trust company which is organized
under the laws of the United States of America or any state thereof, and which
bank or trust company has, or the obligation of which bank or trust company is
guaranteed by a bank or trust company which has, capital, surplus and undivided
profits aggregating in excess of $150,000,000 and has outstanding debt which is
rated "A" (or such similar equivalent rating) or higher by at least one
"nationally recognized statistical rating organization" (as defined in Rule 436
under the Securities Act) or any money-market fund sponsored by a registered
broker dealer or mutual fund distributor, (iii) repurchase obligations with a
term of not more than 30 days for underlying securities of the types described
in clause (i) above entered into with a bank meeting the qualifications
described in clause (ii) above, (iv) investments in commercial paper, maturing
not more than 180 days after the date of acquisition, issued by a corporation
(other than an Affiliate of the Company) organized and in existence under the
laws of the United States of America with a rating at the time as of which any
investment therein is made of "P-1" (or higher) according to Moody's or "A-1"
(or higher) according to Standard & Poor's, (v) investments in securities with
maturities of six months or less from the date of acquisition issued or fully
guaranteed by any state, commonwealth, territory or province of the United
States of America or by any political subdivision or taxing authority thereof,
and rated at least "A" by Standard & Poor's or "A-2" by Moody's, (vi) other debt
obligations maturing in 365 days or less issued by a corporation (other than an
Affiliate of the Company) organized under the laws of the United States or any
state thereof and rated at least "A-" by S&P or "A3" by Moody's and (vii) with
respect to any Foreign Subsidiary, investments by such Foreign Subsidiary that
are comparable to those described in clauses (iv) and (v) above but with respect
to such Foreign Subsidiary's country of organization or country in which it
conducts its business operations.

     "Euroclear" means the Euroclear Clearance System (or any successor
securities clearing agency).

     "Event of Default" has the meaning set forth in Section 6.01.

     "Excess Proceeds" has the meaning set forth in Section 4.08(b).

     "Exchange Act" means the Securities Exchange Act of 1934, as amended, and
the rules and regulations promulgated thereunder.

     "Exchange Note" means any Note issued in exchange for an Original Note or
Original Notes pursuant to the Registered Exchange Offer or otherwise registered
under the Securities Act and any Successor Note thereto.

     "Exchange Offer Registration Statement" has the meaning set forth in the
form of the Notes contained in Section 2.03.

     "Fair Market Value" means, with respect to any asset or Property, the sale
value that would be obtained in an arm's-length transaction between an informed
and

                                       8
<PAGE>

willing seller under no compulsion to sell and an informed and willing buyer
under no compulsion to buy, as determined in good faith by the Board of
Directors.

     "Foreign Subsidiary" means any Restricted Subsidiary of the Company which
(i) is not organized under the laws of the United States, any state thereof or
the District of Columbia, and (ii) conducts substantially all of its business
operations outside the United States of America.

     "GAAP" means generally accepted principles in the United States,
consistently applied, which are in effect on the date of this Indenture.

     "Global Note(s)" means the Note or Notes that evidences all or part of the
Notes and bears the legend set forth in Section 2.02.

     "Guarantee" means any direct or indirect obligation, contingent or
otherwise, of a Person guaranteeing or having the economic effect of
guaranteeing any Indebtedness of any other Person in any manner (and
"Guaranteed," "Guaranteeing" and "Guarantor" shall have meanings correlative to
the foregoing); provided that the term "Guaranteed" and any meaning correlative
thereto shall not include endorsements for collection or deposit.

     "Holder" means (i) in the case of any certificated Note, the Person in
whose name such certificated Note is registered in the Note Register and (ii) in
the case of any Global Note, the Depositary.

     "Incur" means, with respect to any Indebtedness or other obligation of any
Person, to create, issue, incur (by conversion, exchange or otherwise), assume,
Guarantee or otherwise become liable in respect of such Indebtedness or other
obligation including by acquisition of Subsidiaries or the recording, as
required pursuant to GAAP or otherwise, of any such Indebtedness or other
obligation on the balance sheet of such Person (and "Incurrence," "Incurred,"
"Incurrable" and "Incurring" shall have meanings correlative to the foregoing);
provided that a change in GAAP that results in an obligation of such Person that
exists at such time becoming Indebtedness shall not be deemed an Incurrence of
such Indebtedness and that the accrual of interest shall not be deemed an
Incurrence of Indebtedness. Indebtedness otherwise Incurred by a Person before
it becomes a Subsidiary of the Company (whether by merger, amalgamation,
consolidation, acquisition or otherwise) shall be deemed to have been Incurred
by the Company at the time at which such Person becomes a Subsidiary of the
Company.

     "Indebtedness" means, at any time (without duplication), with respect to
any Person, whether recourse is to all or a portion of the assets of such
Person, and whether or not contingent, (i) any obligation of such Person for
money borrowed, (ii) any obligation of such Person evidenced by bonds,
debentures, notes, Guarantees or other similar instruments, including any such
obligations incurred in connection with the acquisition of Property, assets or
businesses, excluding trade accounts payable made in the ordinary course of
business, (iii) any reimbursement obligation of such Person with respect to
letters of credit, bankers' acceptances or similar facilities issued for the
account of such Person, (iv) any obligation of such Person issued or assumed as
the deferred purchase price of Property or services (but excluding trade
accounts payable or accrued liabilities arising in the ordinary course of
business, which in either case are being contested in good faith), (v) any
Capital Lease Obligation of such Person, (vi) the maximum fixed redemption or
repurchase price of Disqualified Stock of such Person and,

                                       9
<PAGE>

to the extent held by Persons other than such Person or its Restricted
Subsidiaries, the maximum fixed redemption or repurchase price of Preferred
Stock of such Person's Restricted Subsidiaries, at the time of determination,
(vii) any Attributable Indebtedness with respect to any Sale and Leaseback
Transaction to which such Person is a party, (viii) Indebtedness of other
Persons secured by a Lien to which the Property owned or held by such first
Person is subject, whether or not the obligation or obligations secured thereby
shall have been assumed (the amount of such Indebtedness being deemed to be the
lesser of the value of such property and assets or the amount of the
Indebtedness so secured) and (ix) any obligation of the type referred to in
clauses (i) through (viii) of this definition of another Person and all
dividends and distributions of another Person the payment of which, in either
case, such Person has Guaranteed or is responsible or liable for, directly or
indirectly, as obligor, Guarantor or otherwise. For purposes of the preceding
sentence, the maximum fixed repurchase price of any Disqualified Stock or
Preferred Stock that does not have a fixed repurchase price shall be calculated
in accordance with the terms of such stock as if such stock were repurchased on
any date on which Indebtedness shall be required to be determined pursuant to
this Indenture; provided that, if such stock is not then permitted to be
repurchased, the repurchase price shall be the book value of such stock. The
amount of Indebtedness of any Person at any date shall be the outstanding
balance at such date of all unconditional obligations as described above and,
with respect to contingent obligations, the maximum liability upon the
occurrence of the contingency giving rise to the obligation; provided that the
amount outstanding at any time of any Indebtedness issued with original issue
discount is the face amount of such Indebtedness less the remaining unamortized
portion of the original issue discount of such Indebtedness at such time as
determined in conformity with GAAP.

     "Indenture" means this instrument as originally executed or as it may from
time to time be supplemented or amended by one or more indentures supplemental
hereto entered into pursuant to the applicable provisions hereof, including, for
all purposes of this instrument and any such supplemental indenture, the
provisions of the Trust Indenture Act that are deemed to be a part of and govern
this instrument, and any such supplemental indenture, respectively.

     "Initial Purchasers" means Salomon Smith Barney Inc., Donaldson, Lufkin &
Jenrette Securities Corporation, Morgan Stanley & Co. Incorporated, TD
Securities (USA) Inc. and Banc of America Securities LLC.

     "Investment" in any Person means any direct, indirect or contingent (i)
advance or loan to, Guarantee of any Indebtedness of, extension of credit or
capital contribution to such Person, (ii) the acquisition of any shares of
Capital Stock, bonds, notes, debentures or other securities of such Person, or
(iii) the acquisition, by purchase or otherwise, of all or substantially all of
the business, assets or stock or other evidence of beneficial ownership of such
Person; provided that Investments shall exclude extensions of trade credit in
the ordinary course of business. The amount of any Investment shall be the
original cost of such Investment, plus the cost of all additions thereto and
minus the amount of any portion of such Investment repaid to such Person in cash
as a repayment of principal or a return of capital, as the case may be, but
without any other adjustments for increases or decreases in value, or write-ups,
write-downs or write-offs with respect to such Investment. In determining the
amount of any Investment involving a transfer of any Property other than cash,
such Property shall be valued at its Fair Market Value at the time of such
transfer.

                                      10
<PAGE>

     "Issue Date" means the date on which the Notes are first authenticated and
delivered under this Indenture.

     "Lien" means, with respect to any Property or other asset, any mortgage or
deed of trust, pledge, hypothecation, assignment, deposit arrangement, security
interest, lien (statutory or other), charge, set-off right, easement,
encumbrance, preference, priority or other security or similar agreement or
preferential arrangement of any kind or nature whatsoever on or with respect to
such Property or other asset (including any conditional sale or title retention
agreement having substantially the same economic effect as any of the
foregoing).

     "Maturity" means, when used with respect to a Note, the date on which the
principal of such Note becomes due and payable as provided therein or in this
Indenture, whether on the Change of Control Payment Date or purchase date
established pursuant to the terms of this Indenture with regard to an Asset Sale
Offer, as applicable, or by declaration of acceleration, call for redemption or
otherwise.

     "Moody's" means Moody's Investors Service, Inc., or, if Moody's Investors
Service, Inc. shall cease rating the specified debt securities and such ratings
business with respect thereto shall have been transferred to a successor Person,
such successor Person; provided that if Moody's Investors Service, Inc. ceases
rating the specified debt securities and its ratings business with respect
thereto shall not have been transferred to any successor Person or such
successor Person is Duff & Phelps or Standard & Poor's, then "Moody's" shall
mean any other "nationally recognized statistical rating organization" (as
defined in Rule 436 under the Securities Act) (other than Duff & Phelps or
Standard & Poor's, as applicable, if either is such successor Person) that rates
the specified debt securities and that shall have been designated by the Company
in an Officers' Certificate.

     "Net Cash Proceeds" means (i) with respect to the sale of any Property or
other assets by the Company or any of the Restricted Subsidiaries, Cash Proceeds
received net of (a) all reasonable out-of-pocket expenses of the Company or such
Restricted Subsidiary incurred in connection with such sale, including, all
legal, title and recording tax expenses, commissions and other fees and expenses
incurred (but excluding any finder's fee or broker's fee payable to any
Affiliate of the Company) and all U.S. federal, state, provincial, foreign and
local taxes arising in connection with such sale that are paid or required to be
accrued as a liability under GAAP by the Company or its Restricted Subsidiaries,
(b) all payments made or required to be made by the Company or its Restricted
Subsidiaries on any Indebtedness which is secured by such Properties or other
assets in accordance with the terms of any Lien upon or with respect to such
Properties or other assets or which must, by the terms of such Lien, or in order
to obtain a necessary consent to such transaction or by applicable law, be
repaid in connection with such sale, (c) all contractually required
distributions and other payments made to minority interest holders (but
excluding distributions and payments to Affiliates of the Company) in Restricted
Subsidiaries as a result of such transaction and (d) appropriate amounts to be
provided by the Company or any Restricted Subsidiary, as the case may be, as a
reasonable reserve against any liabilities associated with such assets and
retained by the Company or any Restricted Subsidiary thereof, as the case may
be, after such transaction, including liabilities under any indemnification
obligations and severance and other employee termination costs associated with
such transaction, in each case as determined by the Board of Directors, in its
reasonable good faith judgment evidenced by a Board Resolution; provided that,
in the event that any consideration for a transaction (which

                                      11
<PAGE>

would otherwise constitute Net Cash Proceeds) is required to be held in escrow
pending determination of whether a purchase price adjustment or indemnification
or other payment or similar adjustment will be made, such consideration (or any
portion thereof) shall become Net Cash Proceeds only at such time as it is
released to the Company or the Restricted Subsidiaries from escrow; and
provided, further, that any non-cash consideration received in connection with
any transaction, which is subsequently converted to cash, shall be deemed to be
Net Cash Proceeds at such time, and shall thereafter be applied in accordance
with this Indenture and (ii) with respect to any sale, issuance, transfer or
other disposition of Capital Stock, the proceeds of such sale, issuance,
transfer or other disposition in the form of cash or cash equivalents, net of
attorneys' fees, accountants' fees, underwriters' or placement agents' fees,
discounts or commissions and brokerage, consultant and other fees and reasonable
out-of-pocket expenses of the Company or any Subsidiary of the Company incurred
in connection with such sale, issuance, transfer or other disposition and net of
taxes paid or payable as a result thereof.

     "Note Register" and "Note Registrar" have the respective meanings specified
in Section 2.06(a).

     "Notes" has the meaning set forth in the Recitals to this Indenture and
more particularly means any of the Notes authenticated and delivered under this
Indenture, including the Original Notes and the Exchange Notes, as the context
may require.

     "Offer Purchase Price" has the meaning set forth in Section 4.08(c).

     "Officer" means the Chairman of the Board of Directors, a Vice Chairman of
the Board of Directors, the President, an Executive Vice President, the Chief
Executive Officer, the Chief Financial Officer, the Chief Accounting Officer,
the Treasurer, an Assistant Treasurer, the Corporate Secretary or an Assistant
Secretary.

     "Officers' Certificate" means a certificate signed by (i) the President or
the Chief Executive Officer and (ii) the Chief Accounting Officer, Chief
Financial Officer or the Treasurer, of the Company and delivered to the Trustee,
which shall comply with Section 10.04, to the extent applicable.

     "Opinion of Counsel" means a written opinion from legal counsel (who may be
counsel to the Company or the Trustee) who is acceptable to the Trustee, which
opinion shall comply with the provisions of Section 10.04, to the extent
applicable.

     "Original Notes" means all Notes other than Exchange Notes.

     "Paying Agent" means any Person authorized by the Company to make payments
of principal, premium or interest with respect to the Notes on behalf of the
Company.

     "Permanent Regulation S Global Note" has the meaning set forth in Section
2.08(g)(v).

     "Permitted Holders" means Madison Dearborn Partnership L.P., Frontenac
V.I.L.P. and Battery Ventures III, L.P., and Affiliates (other than the Company
and the Restricted Subsidiaries) of each of the foregoing.

                                      12
<PAGE>

     "Permitted Investments" means (i) Eligible Cash Equivalents, (ii)
Investments in any Person engaged in a Telecommunications Business as a result
of which such Person becomes a Restricted Subsidiary in compliance with this
Indenture, (iii) Investments pursuant to agreements or obligations of the
Company or a Restricted Subsidiary, in effect on the Issue Date, to make
Investments in clause (ii) above, (iv) Investments in prepaid expenses,
negotiable instruments held for collection and lease, utility and workers'
compensation, performance and other similar deposits, (v) Investments, Capital
Stock, bonds, notes, debentures or other debt or equity securities received as a
result of Asset Sales permitted under Section 4.08, (vi) Investments in
existence at the Issue Date, (vii) commission, payroll, travel and similar
advances made in the ordinary course of business to cover matters that are
expected at the time of such advances ultimately to be treated as expenses in
accordance with GAAP, (viii) loans or advances to employees and directors made
in the ordinary course of business at any time outstanding not to exceed in the
aggregate $5,000,000 and (ix) stock, obligations or securities received in
satisfaction of judgments.

     "Permitted Liens" means (i) Liens for taxes, assessments, governmental
charges or claims which are not yet delinquent or which are being contested in
good faith by appropriate proceedings, if a reserve or other appropriate
provision, if any, as shall be required in conformity with GAAP shall have been
made therefor, (ii) other Liens incidental to the conduct of the Company's or a
Restricted Subsidiary's business or the ownership of its Property and assets,
and which do not in the aggregate materially detract from the value of the
Company's and its Restricted Subsidiaries' Property or other assets when taken
as a whole, or materially impair the use thereof in the operation of its
business, (iii) Liens with respect to assets of a Restricted Subsidiary granted
by such Restricted Subsidiary to secure Indebtedness owing to the Company, (iv)
Liens incurred or pledges and deposits made in the ordinary course of business
in connection with workers' compensation and unemployment insurance and other
types of social security, (v) statutory Liens of landlords, carriers,
warehousemen, mechanics, materialmen, repairmen and other types of statutory
obligations, (vi) deposits made to secure the performance of tenders, bids,
leases, surety and appeal bonds, government contracts, performance and return-
of-money bonds and other obligations of like nature incurred in the ordinary
course of business (exclusive of obligations for the payment of borrowed money),
(vii) zoning restrictions, servitudes, easements, rights-of-way, restrictions
and other similar charges or encumbrances incurred in the ordinary course of
business which, in the aggregate, do not materially detract from the value of
the Property subject thereto or interfere with the ordinary conduct of the
business of the Company or its Restricted Subsidiaries, (viii) Liens arising out
of judgments or awards against the Company or any Restricted Subsidiary with
respect to which the Company or such Restricted Subsidiary is prosecuting an
appeal or proceeding for review and the Company or such Restricted Subsidiary is
maintaining adequate reserves in accordance with GAAP, (ix) any interest or
title of a lessor in the Property subject to any lease other than a Capital
Lease, (x) leases or subleases granted to others that do not materially
interfere with the ordinary course of business of the Company and its Restricted
Subsidiaries, (xi) Liens encumbering Property or other assets under construction
arising from progress or partial payments by a customer of the Company or its
Restricted Subsidiaries relating to such Property or other assets, (xii) Liens
on Property of, or on shares of stock or Indebtedness of, any corporation
existing at the time such corporation becomes, or becomes a part of, any
Restricted Subsidiary; provided that such Liens do not extend to or cover any
Property or other assets of the Company or any Restricted Subsidiary other than
the Property or other assets acquired, (xiii) Liens securing reimbursement
obligations with respect to letters of credit that encumber documents and other
Property relating to such

                                      13
<PAGE>

letters of credit and the products and proceeds thereof, (xiv) Liens in favor of
customs and revenue authorities arising as a matter of law to secure payment of
customs duties in connection with the importation of goods, (xv) Liens arising
out of conditional sale, title retention, consignment or similar arrangements
for the sale of goods entered into by the Company or any of its Restricted
Subsidiaries in the ordinary course of business, (xvi) Liens on or sales of
receivables and (xvii) Liens in favor of the Trustee pursuant to this Indenture.

     "Person" means any individual, corporation, limited liability company,
partnership, limited liability partnership, joint venture, trust, unincorporated
organization or government or any agency or political subdivision thereof.

     "Predecessor Note" of any particular Note means every previous Note
evidencing all or a portion of the same Indebtedness as that evidenced by such
particular Note; and, for the purposes of this definition, any Note
authenticated and delivered under Section 2.09 in exchange for or in lieu of a
mutilated, destroyed, lost or stolen Note shall be deemed to evidence the same
debt as the mutilated, destroyed, lost or stolen Note.

     "Preferred Stock" of any Person means Capital Stock of such Person of any
class or classes (however designated) that ranks prior, as to the payment of
dividends or as to the distribution of assets upon any voluntary or involuntary
liquidation, dissolution or winding up of such Person, to shares of Capital
Stock of any other class of such Person.

     "pro forma" means, with respect to any calculation made or required to be
made pursuant to the terms hereof, a calculation in accordance with Article 11
of Regulation S-X promulgated under the Securities Act (to the extent
applicable), as interpreted in good faith by the Board of Directors, or
otherwise, a calculation made in good faith by the Board of Directors, as the
case may be.

     "Property" means, with respect to any Person, any interest of such Person
in any kind of property or other asset, whether real, personal or mixed, or
tangible or intangible, excluding Capital Stock of any other Person.

     "Public Equity Offering" means an underwritten primary public offering of
the Common Stock of the Company pursuant to an effective registration statement
under the Securities Act.

     A "Public Market" shall be deemed to exist if (i) a Public Equity Offering
has been consummated and (ii) at least 15% of the total issued and outstanding
Common Stock of the Company immediately prior to the consummation of such Public
Equity Offering has been distributed by means of an effective registration
statement under the Securities Act or sales pursuant to Rule 144 under the
Securities Act.

     "Purchase Agreement" means the Purchase Agreement, dated as of January 7,
2000 among the Company and the Initial Purchasers, as such agreement may be
amended from time to time.

     "Qualified Stock" of any Person means a class of Capital Stock other than
Disqualified Stock.

                                      14
<PAGE>

     "Redemption Date" means, when used with respect to any Note or part thereof
to be redeemed hereunder, the date fixed for redemption of such Notes pursuant
to the terms of the Notes and this Indenture.

     "Redemption Price" means, when used with respect to any Note or part
thereof to be redeemed hereunder, the price fixed for redemption of such Note
pursuant to the terms of the Notes and this Indenture, plus accrued and unpaid
interest thereon, if any, to the Redemption Date.

     "Registered Exchange Offer" has the meaning set forth in the form of the
Notes contained in Section 2.03.

     "Registration Agreement" means the Exchange and Registration Agreement,
dated as of January   , 2000, between the Company and the Initial Purchasers, as
such agreement may be amended from time to time.

     "Regular Record Date" means, for the interest payable on any interest
payment date, the date specified in Section 2.13(a).

     "Regulation S" means Regulation S under the Securities Act (or any
successor provision), as it may be amended from time to time.

     "Regulation S Certificate" means a certificate substantially in the form
set forth in Annex A hereof.

     "Regulation S Global Note" has the meaning specified in Section 2.01(c).

     "Regulation S Notes" means all Notes offered and sold outside the United
States in reliance on Regulation S. Such term includes the Regulation S Global
Note.

     "Restricted Global Note" has the meaning specified in Section 2.01(c).

     "Restricted Notes" means all Notes offered and sold to "qualified
institutional buyers" (as defined in Rule 144A) in reliance on Rule 144A. Such
term includes the Restricted Global Note.

     "Restricted Notes Certificate" means a certificate substantially in the
form set forth in Annex B hereof.

     "Restricted Payment" means (i) a dividend or other distribution declared or
paid on the Capital Stock of the Company or to the Company's stockholders (in
their capacity as such), or declared or paid to any Person other than the
Company or a Restricted Subsidiary on the Capital Stock of any Restricted
Subsidiary, in each case, other than dividends, distributions or payments made
solely in Qualified Stock of the Company or such Restricted Subsidiary and other
than pro rata dividends or other distributions made by a Restricted Subsidiary
that is not a Significant Restricted Subsidiary to minority stockholders (or
owners of an equivalent interest in the case of a Restricted Subsidiary that is
an entity other than a corporation), (ii) a payment made by the Company or any
of its Restricted Subsidiaries (other than to the Company or any Restricted
Subsidiary) to purchase, redeem, acquire or retire any Capital Stock of the
Company or (iii) a payment made by the Company or any of its Restricted
Subsidiaries (other than a payment made solely in Qualified Stock of the
Company) to redeem,

                                      15
<PAGE>

repurchase, defease (including an in-substance or legal defeasance) or otherwise
acquire or retire for value (including pursuant to mandatory repurchase
covenants), prior to any scheduled maturity, scheduled sinking fund or mandatory
redemption payment, Indebtedness of the Company which is subordinate (whether
pursuant to its terms or by operation of law) in right of payment to the Notes
and which was scheduled to mature on or after the maturity of the Notes (other
than permitted refinancings thereof) or (iv) an Investment in any Person,
including an Unrestricted Subsidiary or the designation of a Subsidiary as an
Unrestricted Subsidiary, other than (a) a Permitted Investment, (b) an
Investment by the Company in a Restricted Subsidiary engaged in a
Telecommunications Business or (c) an Investment by a Restricted Subsidiary in
the Company or in a Restricted Subsidiary engaged in a Telecommunications
Business.

          "Restricted Period" means the period of 40 consecutive days beginning
on and including the later of (i) the day on which Notes are first offered to
persons other than distributors (as defined in Regulation S) in reliance on
Regulation S and (ii) the Issue Date.

          "Restricted Subsidiary" means any Subsidiary of the Company that has
not been designated as an Unrestricted Subsidiary pursuant to Section 4.17.

          "Rule 144" means Rule 144 under the Securities Act (or any successor
provision), as it may be amended from time to time.

          "Rule 144A" means Rule 144A under the Securities Act (or any successor
provision), as it may be amended from time to time.

          "Rule 144A Notes" means the Notes purchased by the Initial Purchasers
from the Company pursuant to the Purchase Agreement, other than the Regulation S
Notes.

          "Sale and Leaseback Transaction" means, with respect to any Person,
any direct or indirect arrangement pursuant to which Property is sold or
transferred by such Person or a Restricted Subsidiary of such Person and is
thereafter leased back from the purchaser or transferee thereof by such Person
or one of its Restricted Subsidiaries.

          "SEC Reports" has the meaning set forth in Section 4.18(a).

          "Securities Act" means the Securities Act of 1933, as amended, and the
rules and regulations promulgated thereunder.

          "Securities Act Legend" means a legend substantially in the form of
legend required in the form of Note set forth in Section 2.02 to be placed upon
each Regulation S Note and each Restricted Note.

          "Senior Indebtedness" means all Indebtedness of the Company which is
not, expressly by its terms, subordinate or junior in right of payment to the
Notes.

          "Shelf Registration Statement" has the meaning set forth in the form
of the Notes contained in Section 2.03.

                                      16
<PAGE>

          "Significant Restricted Subsidiary" means any Restricted Subsidiary of
which the Company owns, directly or indirectly, 80% or more of all of the
outstanding Capital Stock or other ownership interests (other than any
director's qualifying shares).

          "Special Record Date" means a date fixed by the Trustee pursuant to
Section 2.13(b)(i) for the payment of Defaulted Interest.

          Standard & Poor's" means Standard & Poor's Ratings Group, a division
of McGraw Hill Corporation, or, if Standard & Poor's Ratings Group shall cease
rating the specified debt securities and such ratings business with respect
thereto shall have been transferred to a successor Person, such successor
Person; provided that if Standard & Poor's Ratings Group ceases rating the
specified debt securities and its ratings business with respect thereto shall
not have been transferred to any successor Person or such successor Person is
Duff & Phelps or Moody's, then "Standard & Poor's" shall mean any other
"nationally recognized statistical rating organization" (as defined in Rule 436
under the Securities Act) (other than Duff & Phelps or Moody's, as applicable,
if either is such successor Person) that rates the specified debt securities and
that shall have been designated by the Company in an Officers' Certificate.

          "Stated Maturity" means, with respect to any security, the date
specified in such security as the fixed date on which the payment of principal
of such security is due and payable, including pursuant to any mandatory
redemption provision (but excluding any provision providing for the repurchase
of such security at the option of the holder thereof upon the happening of any
contingency unless such contingency has occurred), and, when used with respect
to any installment of interest on such security, the fixed date on which such
installment of interest is due and payable.

          "Step-Up" has the meaning set forth in the form of the Note contained
in Section 2.03.

          "Subordinated Indebtedness" means Indebtedness of the Company as to
which the payment of principal (and premium, if any) and interest and other
payment obligations in respect of such Indebtedness shall be subordinate to the
prior payment in full of the Notes to at least the following extent:  (i) no
payments of principal (or premium, if any) or interest on or otherwise due in
respect of such Indebtedness may be permitted for so long as any Default in the
payment of principal (or premium, if any) or interest on the Notes exists, (ii)
in the event that any other Default exists, upon notice by Holders of 25% or
more of the aggregate principal amount of the outstanding Notes to the Trustee,
the Trustee shall have the right to give notice to the Company and the holders
of such Indebtedness (or trustees or agents therefor) of a payment blockage, and
thereafter no payments of principal (or premium, if any) or interest on or
otherwise due in respect of such Indebtedness may be made for a period of 179
days from the date of such notice, and (iii) such Indebtedness may not (a)
provide for payments of principal of such Indebtedness at the stated maturity
thereof or by way of a sinking fund applicable thereto or by way of any
mandatory redemption, defeasance, retirement or repurchase thereof by the
Company (including any redemption, retirement or repurchase which is contingent
upon events or circumstances, but excluding any retirement required by virtue of
acceleration of such Indebtedness upon an event of default thereunder), in each
case prior to the final Stated Maturity of the Notes or (b) permit redemption or
other retirement (including pursuant to an offer to purchase made by the
Company) of such other Indebtedness at the option of the holder thereof prior to
the final Stated Maturity of the Notes, other than a redemption or other
retirement at the option of the holder of such

                                      17
<PAGE>

Indebtedness (including pursuant to an offer to purchase made by the Company)
which is conditioned upon a change of control of the Company pursuant to
provisions substantially similar to those described under Section 4.07(a)
through Section 4.07(d) (and which shall provide that such Indebtedness will not
be repurchased pursuant to such provisions prior to the Company's repurchase of
the Notes required to be repurchased by the Company pursuant to the provisions
described under Section 4.07(a) through Section 4.07(d)).

          "Subsidiary" means, with respect to any Person, (i) any corporation
more than 50% of the outstanding shares of Voting Stock of which is owned,
directly or indirectly, by such Person, or by one or more other Subsidiaries of
such Person, or by such Person and one or more other Subsidiaries of such
Person, (ii) any general partnership, joint venture or similar entity, more than
50% of the outstanding partnership or similar interests of which are owned,
directly or indirectly, by such Person, or by one or more other Subsidiaries of
such Person, or by such Person and one or more other Subsidiaries of such Person
and (iii) any limited partnership of which such Person or any Subsidiary of such
Person is a general partner.

          "Successor Note" of any particular Note means every Note issued after,
and evidencing all or a portion of the same Indebtedness as that evidenced by,
such particular Note; and, for the purposes of this definition, any Note
authenticated and delivered under Section 2.09 hereof in exchange for or in lieu
of a mutilated, destroyed, lost or stolen Note shall be deemed to evidence the
same debt as the mutilated, destroyed, lost or stolen Note.

          "Surviving Entity" has the meaning set forth in Section 5.01.

          "Telecommunications Assets" means all assets, rights (contractual or
otherwise) and properties, real or personal, whether tangible or intangible,
used or intended for use in connection with a Telecommunications Business.

          "Telecommunications Business" means the business of (i) transmitting,
or providing services relating to the transmission of, voice, video or data
through owned or leased wireline or wireless transmission facilities, (ii)
creating, developing, constructing, installing, repairing, maintaining or
marketing communications-related systems, network equipment and facilities,
software and other products, or (iii) evaluating, owning, operating,
participating in or pursuing any other business that is primarily related to
those identified in the foregoing clauses (i) or (ii) above (in the case of this
clause (iii), however, in a manner consistent with the Company's manner of
business on the Issue Date), and shall, in any event, include all businesses in
which the Company or any of its Subsidiaries are engaged on the Issue Date or
have entered into agreements to engage in or to acquire a company to engage in
or contemplate engaging in, as expressly set forth in the final offering
memorandum relating to the offering of the Original Notes by the Initial
Purchasers; provided that the determination of what constitutes a
Telecommunications Business shall be made in good faith by the Board of
Directors.

          "Temporary Notes" has the meaning set forth in Section 2.11(a).

          "Temporary Regulation S Global Notes" has the meaning set forth in
Section 2.01(c).

          "Total Net Incremental Equity" means, at any time of determination,
the sum of, without duplication (i) the aggregate Net Cash Proceeds received by
the

                                      18
<PAGE>

Company from capital contributions in respect of existing Capital Stock (other
than Disqualified Stock) or the issuance or sale of Capital Stock (other than
Disqualified Stock or Qualified Stock to the extent the proceeds of such
Qualified Stock are used to retire any Capital Stock or Indebtedness of the
Company pursuant to Section 4.11(b)(ii) but including Capital Stock issued upon
the conversion of convertible Indebtedness or from the exercise of options,
warrants or rights to purchase Capital Stock (other than Disqualified Stock))
subsequent to the Issue Date, other than to a Subsidiary of the Company, plus
(ii) the Fair Market Value (determined at the time of issuance) of any Capital
Stock (other than Disqualified Stock) of the Company issued as consideration for
the acquisition of Capital Stock or assets of any Person engaged in the
Telecommunications Business, plus (iii) the aggregate Net Cash Proceeds received
by the Company or any Restricted Subsidiary from the sale, disposition, maturity
or repayment (in whole or in part) of any Investment that is made after the
Issue Date and that constituted a Restricted Payment declared or made on and
after the Issue Date to the extent made in reliance on Section 4.11(a)(iii)(C)
or Section 4.11(b)(vi)(B), but only such Net Cash Proceeds up to an amount equal
to the lesser of (a) the return of capital with respect to the applicable
portion of such Investment and (b) the cost of the applicable portion of such
Investment, in either case, less the cost of the disposition of such Investment,
plus (iv) the net reduction in Investments in any Person made pursuant to
Section 4.11(b)(vi)(B) resulting from such Person becoming a Restricted
Subsidiary (valued as provided in the definition of "Investment"), less (v) the
aggregate amount of all Restricted Payments made after the Issue Date (x) to the
extent made in reliance on Section 4.11(a)(iii)(C) or (y) to the extent made in
reliance on Section 4.11(b)(vi)(B).

          "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
effect on the date of this Indenture except as required by Section 9.04;
provided, that in the event the Trust Indenture Act of 1939 is amended after
such date, "Trust Indenture Act" means, to the extent required by any such
amendment, the Trust Indenture Act of 1939, as so amended.

          "Trust Officer" means any officer assigned to the Corporate Trust
Division (or any successor thereto), including any Vice President, Assistant
Vice President, Trust Officer, any Assistant Secretary, any trust officer or any
other officer of the Trustee customarily performing functions similar to those
performed by any of the above designated officers and having direct
responsibility for the administration of this Indenture.

          "Trustee" means the party named as such in this Indenture until a
successor replaces it in accordance with the provisions of this Indenture and,
thereafter, means such successor.

          "Unrestricted Notes Certificate" means a certificate substantially in
the form set forth in Annex C hereof.

          "Unrestricted Subsidiary" means any Subsidiary of the Company that the
Company has classified as an "Unrestricted Subsidiary" and that has not been
reclassified as a Restricted Subsidiary, pursuant to Section 4.17.

          "U.S. Government Obligations" means (i) securities that are (a) direct
obligations of the United States of America for the payment of which the full
faith and credit of the United States of America is pledged or (b) obligations
of a Person controlled or supervised by and acting as an agency or
instrumentality of the United States of

                                      19
<PAGE>

America the payment of which is unconditionally guaranteed as a full faith and
credit obligation by the United States of America, which, in either case, are
not callable or redeemable at the option of the issuer thereof, and (ii)
depository receipts issued by a bank (as defined in Section 3(a)(2) of the
Securities Act) as custodian with respect to any U.S. Government Obligation
which is specified in clause (i) above and held by such bank for the account of
the holder of such depository receipt, or with respect to any specific payment
of principal or interest on any U.S. Government Obligation which is so specified
and held, provided that (except as required by law) such custodian is not
authorized to make any deduction from the amount payable to the holder of such
depository receipt from any amount received by the custodian in respect of the
U.S. Government Obligation or the specific payment of principal or interest of
the U.S. Government Obligation evidenced by such depository receipt.

          "Voting Stock" means, with respect to any Person, securities of any
class or classes of Capital Stock in such Person entitling the holders thereof
(whether at all times or at the times that such class of Capital Stock has
voting power by reason of the happening of any contingency) to vote in the
election of members of the board of directors or comparable body of such Person.

          "Wholly Owned Restricted Subsidiary" of any Person means a Restricted
Subsidiary of such Person all of the outstanding Capital Stock or other
ownership interests (other than any director's qualifying shares) of which shall
at the time be owned by such Person or by one or more other Wholly Owned
Restricted Subsidiaries of such Person or by such Person and one or more other
Wholly Owned Restricted Subsidiaries of such Person.

          SECTION 1.02  Incorporation by Reference of Trust Indenture Act. (a)
Whenever this Indenture refers to a provision of the Trust Indenture Act, the
provision is incorporated by reference in and made a part of this Indenture.
The following Trust Indenture Act terms incorporated by reference in this
Indenture have the following meanings:

          (i)    "indenture securities" means the Notes;

          (ii)   "indenture security holder" means a Holder;

          (iii)  "indenture to be qualified" means this Indenture;

          (iv)   "indenture trustee" or "institutional trustee" means the
     Trustee; and

          (v)    "obligor" on the indenture securities means the Company or
     other obligor on the Notes, if any.

          (b)    All other Trust Indenture Act terms used or incorporated by
reference in this Indenture that are defined by the Trust Indenture Act, defined
by Trust Indenture Act reference to another statute or defined by Commission
rule have the meanings assigned to them therein.

          SECTION 1.03  Rules of Construction.  Unless the context otherwise
requires:

                                      20
<PAGE>

               (a)  words "herein", "hereof" and "hereunder", and other words of
     similar import, refer to this Indenture as a whole and not to any
     particular Article, Section or other subdivision;

               (b)  Section number and article number references are to sections
     or articles of this Indenture, unless the context indicates otherwise;

               (c)  "or" is not exclusive;

               (d)  "including" means including without limitation;

               (e)  all references herein to "interest" on the Notes shall
     include Additional Interest; and

               (f)  all dollar amounts are expressed in United States dollars.

          SECTION 1.04  Form of Documents Delivered to Trustee.  (a) In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters, and any such Person may certify or give an opinion as to
such matters in one or several documents.

          (b)  Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

          SECTION 1.05. Acts of Holders. (a) Any request, demand, authorization,
direction, notice, consent, waiver or other action provided by this Indenture to
be given or taken by Holders may be embodied in and evidenced by one or more
instruments of substantially similar tenor signed by such Holders in person or
by an agent duly appointed in writing; and, except as herein otherwise expressly
provided, such action shall become effective when such instrument or instruments
are received by the Trustee and, where it is hereby expressly required, to the
Company. Such instrument or instruments (and the action embodied therein and
evidenced thereby) are herein sometimes referred to as the "Act" of the Holders
signing such instrument or instruments. Proof of execution of any such
instrument or of a writing appointing any such agent shall be sufficient for any
purpose of this Indenture and (subject to Section 7.01) conclusive in favor of
the Trustee and the Company, if made in the manner provided in this Section.

          (b)  The fact and date of the execution by any Person of any such
instrument or writing may be proved by the affidavit of a witness of such
execution or by an acknowledgment of a notary public or other officer authorized
by law to take acknowledgments of deeds, certifying that the individual signing
such instrument or writing acknowledged to him the execution thereof. Where such
execution is by a signer acting in a capacity other than such signer's
individual capacity, such certificate or affidavit shall also constitute
sufficient proof of the signer's authority. The fact and date of the execution
of any such instrument or writing, or the authority of the person executing the
same, may also be proved in any other manner which the Trustee deems sufficient.

                                      21
<PAGE>

          (c)  The ownership of Notes shall be proved by the Note Register.

          SECTION 1.06.  Satisfaction and Discharge.  (a) This Indenture shall
cease to be of further effect (except as to the rights of Holders under Sections
2.09, 2.11, 4.02, 4.03 and 4.04) and the Trustee, on receipt of a Company Order
requesting such action, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture, when (i) either (A) all
outstanding Notes have been delivered to the Trustee for cancellation or (B) all
such Notes not theretofore delivered to the Trustee for cancellation (1) have
become due and payable, (2) will become due and payable within one year or (3)
are to be called for redemption within one year under irrevocable arrangements
satisfactory to the Trustee for the giving of notice of redemption by the
Trustee in the name, and at the expense, of the Company, and the Company, in the
case of (1), (2) or (3) above, has irrevocably deposited or caused to be
deposited with the Trustee as trust funds in trust for the purpose, an amount in
United States dollars sufficient to pay and discharge the entire indebtedness on
such Notes not theretofore delivered to the Trustee for cancellation, for
principal (and premium, if any) and interest to, but not including, the date of
such deposit (in the case of Notes which have become due and payable) or to, but
not including, the Redemption Date, together with irrevocable instructions from
the Company in form and substance satisfactory to the Trustee directing the
Trustee to apply such funds to the payment thereof; (ii) the Company has paid or
caused to be paid all other sums payable hereunder by the Company; and (iii) the
Company has delivered to the Trustee an Officers' Certificate and an Opinion of
Counsel, each stating that all conditions precedent herein provided for relating
to the satisfaction and discharge of this Indenture have been complied with.
Notwithstanding the satisfaction and discharge of this Indenture pursuant to
this Section 1.06, the obligations of the Company to the Trustee under Section
7.07, and, if funds shall have been deposited with the Trustee in trust for the
Holders pursuant to this Section 1.06, the obligations of the Trustee under this
Section 1.06 and Section 4.03 shall survive.

          (b)  All money deposited with the Trustee pursuant to this Section
1.06 shall be held in trust and applied by it, in accordance with the provisions
of the Notes and this Indenture, to the payment, either directly or through any
Paying Agent, to the Persons entitled thereto, of the principal (and premium, if
any) and interest for the payment of which such money has been deposited with
the Trustee. If the Trustee or Paying Agent is unable to apply any money in
accordance with this Section 1.06 by reason of any legal proceeding or by reason
of any order or judgment of any court or governmental authority enjoining,
restraining or otherwise prohibiting such application, the Company's obligations
under this Indenture and the Notes shall be revived and reinstated as though no
deposit had occurred pursuant to this Section 1.06 until such time as the
Trustee or Paying Agent is permitted to apply all such money in accordance with
this Section 1.06; provided that, if the Company has made any payment of
interest on or principal, or premium, if any, on any Notes because of the
reinstatement of its obligations, the Company shall be subrogated to the rights
of the Holders of such Notes to receive such payment from the cash held by the
Trustee or Paying Agent.

                                  ARTICLE II
                                   The Notes
                                   ---------

          SECTION 2.01. Form and Dating.  (a) The Notes and the certificate of
authentication of the Trustee thereon shall be substantially in the form
contained in this Article II, with such appropriate insertions, substitutions
and other variations as are

                                      22
<PAGE>

required or permitted under this Indenture. Upon issuance, any such Note shall
be duly executed by the Company and authenticated by the Trustee as hereinafter
provided.

          (b)  The Notes may have such letters, numbers or other marks of
identification and such legends and endorsements, stamped, printed, lithographed
or engraved thereon, (i) as may be required to comply with this Indenture, any
law or any rule of any securities exchange on which the Notes may be listed, or
any agreement to which the Company is subject and (ii) as may be necessary to
conform to customary usage. Each Note shall be dated the date of its
authentication by the Trustee.

          (c)  Upon their original issuance, Rule 144A Notes shall be issued in
the form of one or more Global Notes registered in the name of the Depositary or
its nominee and deposited with the Trustee, as custodian for the Depositary,
duly executed by the Company and authenticated by the Trustee, for credit by the
Depositary to the respective accounts of beneficial owners of the Notes
represented thereby (or such other accounts as they may direct).  Such Global
Notes, together with their Successor Notes which are Global Notes other than the
Regulation S Global Note, are collectively herein called the "Restricted Global
Note".  Upon their original issuance, Regulation S Notes shall be issued in the
form of one or more temporary Global Notes registered in the name of the
Depositary or its nominee and deposited with the Trustee as custodian for the
Depositary, duly executed by the Company and authenticated by the Trustee, for
credit to the Agent Member accounts at the Depositary of Euroclear and/or CEDEL
for further credit by Euroclear and CEDEL, as the case may be, to the respective
accounts of the beneficial owners of the Notes represented thereby (or such
other accounts as they may direct) at Morgan Guaranty Trust Company of New York,
Brussels office, as operator of the Euroclear System or CEDEL (the "Temporary
Regulation S Global Notes").  Interests in the Temporary Regulation S Global
Notes may only be held by the Agent Members of the Depositary for Euroclear and
CEDEL.  Such Temporary Regulation S Global Notes, together with their Successor
Notes which are Global Notes (including Permanent Regulation S Global Notes, as
defined in Section 2.08(g)(v)) other than the Restricted Global Note are
collectively herein called the "Regulation S Global Note".

          (d)  Agent Members shall have no rights under this Indenture with
respect to any Global Note held on their behalf by the Depositary or its nominee
or by the Trustee, as custodian for the Depositary, or under such Global Note,
and the Depositary may be treated by the Company, the Trustee and any agent of
the Company or the Trustee as the absolute owner of such Global Note for all
purposes whatsoever. Notwithstanding the foregoing, nothing herein shall prevent
the Company, the Trustee or any agent of the Company or the Trustee from giving
effect to any written certification, proxy or other authorization furnished by
the Depositary or impair, as between the Depositary and its Agent Members, the
operation of customary practices of such Depositary governing the exercise of
the rights of a holder of a beneficial ownership interest in any Global Note.

          (e)  Except as provided in Section 2.08(i)(ii), owners of beneficial
ownership interests in Global Notes will not be entitled to receive physical
delivery of certificated Notes.

          SECTION 2.02. Form of Face of Note. If a Global Note to be held by The
Depository Trust Company or its nominee, then insert--UNLESS THIS CERTIFICATE IS
PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW
YORK CORPORATION ("DTC"), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF
TRANSFER,

                                      23
<PAGE>

EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF
CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE
OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE, OR
OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH
AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

          TRANSFERS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS IN WHOLE,
BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR SUCH
SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL NOTE SHALL BE
LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE
INDENTURE REFERRED TO ON THE REVERSE HEREOF.

     [If Restricted Notes or Regulation S Notes, then insert- THIS NOTE HAS NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
ACT").  THE HOLDER BY PURCHASING THIS NOTE AGREES FOR THE BENEFIT OF THE COMPANY
AND THE INITIAL PURCHASERS OF THIS NOTE THAT THIS NOTE MAY NOT BE RESOLD,
PLEDGED OR OTHERWISE TRANSFERRED (X) PRIOR TO THE SECOND ANNIVERSARY (OR SUCH
EARLIER DATE PROVIDED FOR IN RULE 144(K) UNDER THE SECURITIES ACT OR ANY
SUCCESSOR PROVISION THERETO) OF THE ISSUANCE HEREOF (OR A PREDECESSOR NOTE
HERETO) OR (Y) IF LATER, BY ANY HOLDER THAT WAS AN AFFILIATE OF THE COMPANY AT
ANY TIME DURING THE THREE MONTHS PRECEDING THE DATE OF SUCH TRANSFER, IN EITHER
CASE OTHER THAN (1) TO THE COMPANY, (2) SO LONG AS THIS NOTE IS ELIGIBLE FOR
RESALE PURSUANT TO RULE 144A UNDER THE SECURITIES ACT ("RULE 144A"), TO A PERSON
WHOM THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER WITHIN
THE MEANING OF RULE 144A PURCHASING FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A
QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE RESALE, PLEDGE OR
OTHER TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A (AS INDICATED BY THE BOX
CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS
NOTE), (3) IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH REGULATION S UNDER THE
SECURITIES ACT (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE
CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS NOTE), AND, IF SUCH TRANSFER IS
BEING EFFECTED BY CERTAIN TRANSFERORS SPECIFIED IN THE INDENTURE PRIOR TO THE
EXPIRATION OF THE "40-DAY RESTRICTED PERIOD" (WITHIN THE MEANING OF RULE
903(c)(3) OF REGULATION S UNDER THE SECURITIES ACT), A CERTIFICATE WHICH MAY BE
OBTAINED FROM THE COMPANY OR THE TRUSTEE IS DELIVERED BY THE TRANSFEREE TO THE
COMPANY AND THE TRUSTEE, (4) TO AN INSTITUTION THAT IS AN "ACCREDITED INVESTOR"
AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT (AS
INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON
THE REVERSE OF THIS NOTE) THAT IS ACQUIRING THIS NOTE FOR INVESTMENT PURPOSES
AND NOT FOR DISTRIBUTION IN VIOLATION OF THE SECURITIES ACT OR ANY OTHER
APPLICABLE SECURITIES LAWS, AND A CERTIFICATE

                                      24
<PAGE>

IN THE FORM ATTACHED TO THIS NOTE IS DELIVERED BY THE TRANSFEREE TO THE COMPANY
AND THE TRUSTEE (PROVIDED THAT CERTAIN HOLDERS SPECIFIED IN THE INDENTURE MAY
NOT TRANSFER THIS NOTE PURSUANT TO THIS CLAUSE (4) PRIOR TO THE EXPIRATION OF
THE "40-DAY RESTRICTED PERIOD" (WITHIN THE MEANING OF RULE 903(c)(3) OF
REGULATION S UNDER THE SECURITIES ACT)), (5) PURSUANT TO AN EXEMPTION FROM
REGISTRATION UNDER THE SECURITIES ACT PROVIDED BY RULE 144 (IF APPLICABLE) UNDER
THE SECURITIES ACT, OR (6) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER
THE SECURITIES ACT, IN EACH CASE IN ACCORDANCE WITH ANY APPLICABLE SECURITIES
LAWS OF ANY STATE OF THE UNITED STATES. AN INSTITUTIONAL ACCREDITED INVESTOR
HOLDING THIS NOTE AGREES IT WILL FURNISH TO THE COMPANY AND THE TRUSTEE SUCH
CERTIFICATES AND OTHER INFORMATION AS THE COMPANY MAY REASONABLY REQUIRE TO
CONFIRM THAT ANY TRANSFER BY IT OF THIS NOTE COMPLIES WITH THE FOREGOING
RESTRICTIONS. THE HOLDER HEREOF, BY PURCHASING THIS NOTE, REPRESENTS AND AGREES
FOR THE BENEFIT OF THE COMPANY THAT IT IS (1) A QUALIFIED INSTITUTIONAL BUYER
WITHIN THE MEANING OF RULE 144(A) OR (2) AN INSTITUTION THAT IS AN "ACCREDITED
INVESTOR" AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT
AND THAT IT IS HOLDING THIS NOTE FOR INVESTMENT PURPOSES AND NOT FOR
DISTRIBUTION OR (3) A NON-U.S. PERSON OUTSIDE THE UNITED STATES WITHIN THE
MEANING OF (OR AN ACCOUNT SATISFYING THE REQUIREMENTS OF PARAGRAPH (k)(2) OF
RULE 902 UNDER) REGULATION S UNDER THE SECURITIES ACT.]

                                      25
<PAGE>

                   11.875% SENIOR NOTE DUE JANUARY 15, 2010

CUSIP NO. [    ]

No.                                                                 $

          Focal Communications Corporation, a Delaware corporation (herein
called the "Company", which term includes any successor Person under the
indenture referred to on the reverse of this Note) for value received, hereby
promises to pay to _______________, or registered assigns, the principal amount
of ________ dollars ($__________) [if this Note is a Global Note, then insert:
(which principal amount may from time to time be increased or decreased to such
other principal amounts (which shall not exceed $__________ at any time) by
adjustments made to the Schedule annexed hereto by the Trustee hereinafter
referred to in accordance with the indenture referred to on the reverse of this
Note)] on January 15, 2010.

          Interest Payment Dates:        January 15 and July 15, commencing on
                                         July 15, 2000.

          Regular Record Dates:          January 1 and July 1.

          Reference is hereby made to the further provisions of this Note set
forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

          Unless the certificate of authentication hereon has been executed by
the Trustee referred to on the reverse hereof by manual signature, this Note
shall not be entitled to any benefit under the indenture referred to on the
reverse of this Note or be valid or obligatory for any purpose.

          IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.

Dated:

                                       FOCAL COMMUNICATIONS CORPORATION

                                       by _________________________________
                                          Name:
                                          Title:

Attest:

------------------------

                                      26
<PAGE>

          SECTION 2.03  Form of Reverse of Note.
                        -----------------------

          1.   Indenture.
               ---------

          This Note is one of a duly authorized issue of Notes of the Company
designated as its 11.875% Senior Notes due January 15, 2010 (the "Notes"),
issued under an indenture, dated as of January 12, 2000 (herein, as amended from
time to time, called the "Indenture"), between the Company and Harris Trust and
Savings Bank, as trustee (herein called the "Trustee", which term includes any
successor trustee under the Indenture).  The Notes are limited in aggregate
principal amount to $275,000,000.  Reference is hereby made to the Indenture and
all indentures supplemental thereto for a statement of the respective rights,
limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Holder of this Note and of the terms upon which this Note is,
and is to be, authenticated and delivered.  All terms used in this Note which
are defined in the Indenture shall have the meanings assigned to them in the
Indenture.

          2.  Principal Amount and Interest.
              -----------------------------

          The Company will pay the principal amount of this Note on January 15,
2010.

          This Note will bear interest on the outstanding aggregate principal
amount thereof at a rate of 11.875% per annum computed on a semiannual bond
equivalent basis from the Issue Date.

          [If Original Notes, then insert--If (i) the Company has not filed a
registration statement (the "Exchange Offer Registration Statement") under the
Securities Act of 1933, as amended (the "Securities Act"), registering a
security substantially identical to this Note (except that such Note will not
contain terms with respect to transfer restrictions) pursuant to an exchange
offer (the "Registered Exchange Offer") on or prior to April 14, 2000 or (ii)
the Exchange Offer Registration Statement relating to the Registered Exchange
Offer has not become or been declared effective prior to August 12, 2000, or
(iii) neither the Registered Exchange Offer has been consummated nor a
registration statement registering this Note for resale (a "Shelf Registration
Statement") has been declared effective prior to September 11, 2000 or (iv)
after the Shelf Registration Statement has been declared effective, such Shelf
Registration Statement thereafter ceases to be effective or usable (subject to
certain exceptions set forth in the Registration Agreement) in connection with
resales of this Note or notes issued in exchange for this Note pursuant to the
Registered Exchange Offer ("Exchange Notes") in accordance with and during the
periods specified in the Registration Agreement without being succeeded promptly
by an additional registration statement filed and declared effective, in the
case of each of the immediately preceding clauses (i) through (iv) upon the
terms and conditions set forth in the Registration Agreement (each such event
referred to in such clauses (i) through (iv), a "Registration Default"), then
interest will accrue on this Note and the Exchange Notes (in addition to the
stated interest on this Note and the Exchange Notes) (the "Step-Up") and be
payable in cash semiannually in arrears on January 15 and July 15 of each year,
beginning on the January 15 or July 15 immediately following a Registration
Default (such interest to be payable to the Holder of record as of the January 1
and July 1, as the case may be, immediately preceding January 15 or July 15), at
a rate of 0.50% per annum during the 90-day period immediately following the
occurrence of a Registration Default and shall increase by a rate per annum
equal to 0.25%  at the end of each subsequent 90-day period. In no event shall
such rate exceed 1.50% per annum in the aggregate regardless of the number of
Registration Defaults.]

                                      27
<PAGE>

          [If Exchange Notes, then insert--If after a shelf registration
statement registering this Note for resale (a "Shelf Registration Statement")
has been declared effective, such Shelf Registration Statement thereafter ceases
to be effective or usable (subject to certain exceptions set forth in the
Registration Agreement) in connection with resales of this Note in accordance
with and during the periods specified in the Registration Agreement without
being succeeded promptly by an additional registration statement filed and
declared effective, upon the terms and conditions set forth in the Registration
Agreement (a "Registration Default"), then interest will accrue on this Note (in
addition to the stated interest on this Note) (the "Step-Up") and be payable in
cash semiannually in arrears on January 15 and July 15 of each year, beginning
on the January 15 or July 15 immediately following a Registration Default (such
interest to be payable to the Holder of record as of the January 1 and July 1,
as the case may be, immediately preceding such January 15 or July 15), at a rate
of 0.50% per annum during the 90-day period immediately following the occurrence
of a Registration Default and shall increase by a rate per annum equal to 0.25%
at the end of each subsequent 90-day period. In no event shall such rate exceed
1.50% per annum in the aggregate regardless of the number of Registration
Defaults. Interest accruing as a result of the Step Up is referred to herein as
"Additional Interest." The amount of accrued Additional Interest shall be
determined on the basis of the number of days actually elapsed.]

          The Company shall pay interest on overdue principal and premium, if
any, and interest on overdue installments of interest, to the extent lawful, at
a rate per annum equal to the interest rate payable on this Note.

          Any such interest not so punctually paid or duly provided for will
forthwith cease to be payable to the Holder on such Regular Record Date and may
either be paid to the Person in whose name this Note (or one or more Predecessor
Notes) is registered at the close of business on a Special Record Date for the
payment of such Defaulted Interest to be fixed by the Trustee, notice of which
shall be given to the Holder of this Note not less than 10 calendar days prior
to such Special Record Date.

          3.   Method of Payment.
               -----------------

          The Company will pay principal, premium, if any, and as provided
above, interest in money of the United States that at the time of payment is
legal tender for payment of public and private debts.  Payments in respect of
Notes represented by Global Notes (including principal, premium, interest and
Defaulted Interest, if any) will be made by wire transfer of immediately
available funds to the accounts specified by the nominee for the Depositary.
With respect to certificated Notes, the Paying Agent will make all payments of
principal, premium, interest and Defaulted Interest, if any, by wire transfer of
immediately available funds to the United States dollar accounts maintained by
the Holders entitled thereto with banks in the United States, or, if no such
account is designated by the relevant Holder to the Trustee or the Paying Agent
at least 30 days prior to the relevant due date for payment (or such other date
as the Trustee may accept in its discretion), by mailing a check to the
registered address of such Holder.  If a payment date is a date other than a
Business Day at a place of payment, payment may be made at that place on the
next succeeding day that is a Business Day and no interest shall accrue for the
intervening period.

                                      28
<PAGE>

          4.   Paying Agent and Note Registrar.
               -------------------------------

          Initially, the Trustee will act as authenticating agent, Paying Agent
and Note Registrar.  The Trustee may be removed by action of the Holders of not
less than a majority in principal amount of the outstanding Notes, or by the
Company or certain bona fide Holders of Notes upon the occurrence of certain
events.  The Company may change any Paying Agent or Note Registrar with notice
in writing to the Trustee.  The Company, any Subsidiary or any Affiliate of
either of them may act as Paying Agent or Note Registrar.

          5.  Optional Redemption.
              -------------------

          This Note is subject to redemption upon not less than 30 nor more than
60 days' prior written notice to each Holder of Notes to be redeemed at such
Holder's address appearing in the Note Register, in principal amounts or at any
time on or after January 15, 2005, at the following Redemption Prices plus
accrued and unpaid interest, if any, thereon to but excluding the Redemption
Date, if redeemed during the periods indicated below:

          From and Including    To and Including   Redemption Price
          ------------------    ----------------   ----------------
          January 15, 2005      January 14, 2006       105.938%
          January 15, 2006      January 14, 2007       103.958%
          January 15, 2007      January 14, 2008       101.979%
          January 15, 2008                             100.000%
          and thereafter

          This Note will be redeemable at any time and from time to time prior
to January 15, 2003 in the event that the Company receives Net Cash Proceeds
from the sale of its Capital Stock (other than Disqualified Stock) in one or
more Public Equity Offerings, in which case the Company may, at its option, use
all or a portion of any such Net Cash Proceeds to redeem up to 35% of initially
outstanding aggregate principal amount of the Notes; provided, that at least 65%
of the original aggregate principal amount of the Notes remains outstanding
after each such redemption.  Such redemption must occur on a date of redemption
within 90 days of such sale and upon not less than 30 nor more than 60 days'
prior written notice, in  principal amounts of $1,000 or integral multiples
thereof at a redemption price equal to 111.875% of the principal amount of the
Notes to be redeemed plus Additional Interest, if any, to but excluding the date
of redemption.

          If, after giving effect to the offer by the Company to repurchase all
or any part of each Holder's Notes made upon the occurrence of a Change of
Control as set forth in Section 7 hereto, at least 95% of the original aggregate
principal amount of the Notes has been redeemed or repurchased pursuant to the
Indenture, the Company shall have the right to redeem the balance of the Notes
at a redemption price equal to 101% of the principal amount thereof plus accrued
and unpaid interest, if any, thereon to but excluding the date of redemption.
The Company may exercise this right by giving the Holders notice of such
redemption within 30 days following the payment date with respect to the
Company's earlier repurchase offer.

                                      29
<PAGE>

          6.   No Sinking Fund.
               ---------------

          The Notes do not have the benefit of any sinking fund obligations.

          7.   Repurchase of Notes at the Option of Holders upon a Change of
               -------------------------------------------------------------
Control.
-------

          Upon the occurrence of a Change of Control, each Holder will have the
right to require the Company to repurchase all or any part (equal to $1,000
principal amount or an integral multiple thereof) of such Holder's Notes at a
purchase price ("Change of Control Purchase Price") equal to 101% of the
principal amount thereof plus accrued and unpaid interest, if any, thereon to
but excluding the payment date for the Change of Control Purchase Price.

          Within 30 days following any Change of Control, the Company or the
Trustee (at the expense of the Company) shall mail a notice to each Holder
regarding the Company's offer to repurchase all or any part of such Holder's
Notes.  The Holder of this Note may elect to have this Note or a portion hereof
in an authorized denomination purchased by completing the form entitled "Option
of Holder to Elect Purchase" appearing below and tendering this Note pursuant to
the offer described in the notice.  Unless the Company defaults in the payment
of the Change of Control Purchase Price with respect thereto, all Notes or
portions thereof accepted for payment pursuant to the offer described in the
notice will cease to accrue interest from and after the payment date for the
Change of Control Purchase Price.

          8.   Repurchase of Notes at the Option of Holders upon an Asset Sale.
               ---------------------------------------------------------------

          If at any time the Company or any Restricted Subsidiary engages in any
Asset Sale, as a result of which the aggregate amount of Excess Proceeds
calculated as of any date exceeds $5,000,000, the Company shall, within 30 days
of such date, make an offer to purchase (an "Asset Sale Offer") on a pro rata
basis (a) Notes at a purchase price (the "Offer Purchase Price") in cash equal
to 100% of the principal amount thereof, plus accrued and unpaid interest
thereon, if any, to but excluding the purchase date and (b) to the extent
required by the terms thereof, any other indebtedness of the Company that is
pari passu with the Notes.  The pro rata amount of such Excess Proceeds to be
used to purchase Notes shall be in an amount equal to the aggregate amount of
such Excess Proceeds multiplied by the quotient obtained by dividing the
principal amount of the outstanding Notes by the sum of such principal amount
and the principal amount of such other Indebtedness.  In the event the aggregate
Offer Purchase Price of the outstanding Notes tendered pursuant to an Asset Sale
Offer is in excess of the Excess Proceeds to be used to purchase such Notes,
such Excess Proceeds shall be applied to purchase such Notes on a pro rated
basis in principal amounts of $1,000 or an integral multiple thereof.

          Within 30 days of the date the amount of Excess Proceeds exceeds
$5,000,000, the Company or the Trustee (at the expense of the Company) shall
mail to each Holder a written notice regarding the Asset Sale Offer.  The Holder
of this Note may elect to have this Note or a portion hereof in an authorized
denomination purchased by completing the form entitled "Option of Holder to
Elect Purchase" appearing below and tendering this Note pursuant to the Asset
Sale Offer.  Unless the Company defaults in the payment of the Offer Purchase
Price with respect thereto, all Notes or portions thereof selected for payment
pursuant to the Asset Sale Offer will cease to accrue interest from and after
the purchase date.

                                      30
<PAGE>

          9.   Denominations; Transfer; Exchange.
               ---------------------------------

          The Notes are issuable only in registered form without coupons in
denominations of $1,000 principal amount and any integral multiple thereof.  A
Holder may register the transfer or exchange of Notes in accordance with the
Indenture.  No service charge shall be made for any such registration of
transfer or exchange, but the Company may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

          10.  Persons Deemed Owners.
               ---------------------

          Prior to due presentment of this Note for registration of transfer,
the Company, the Trustee, the Paying Agent and the Note Registrar may deem and
treat the Person in whose name this Note is registered as the owner hereof for
all purposes, whether or not this Note be overdue, and none of the Company, the
Trustee, the Paying Agent or the Note Registrar shall be affected by notice to
the contrary.

          11.  Unclaimed Money.
               ---------------

          Subject to certain notice provisions, the Trustee and the Paying Agent
shall pay to the Company upon written request any money held by them for the
payment of principal, premium, if any, or interest that remains unclaimed for
two years.  After payment to the Company, Holders entitled to such money must
look only to the Company for payment as general creditors, and all
responsibility and liability of the Trustee and the Paying Agent with respect to
such money shall cease.

          12.  Discharge Prior to Redemption.
               -----------------------------

          If the Company deposits with the Trustee United States dollars or U.S.
Government Obligations sufficient to pay the principal, premium, if any, and
accrued interest on the Notes to redemption, the Company will, with the
exceptions of certain sections thereof, be discharged from the Indenture and the
Notes, including certain covenants set forth in the Indenture.

          13.  Amendment; Waiver.
               -----------------

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Notes under the Indenture at any
time by the Company and the Trustee with the consent of the Holders of not less
than a majority in aggregate principal amount of the Notes at the time
outstanding.  The Indenture also contains provisions permitting the Holders of
not less than a majority in aggregate principal amount of the Notes at the time
outstanding, on behalf of the Holders of all the Notes, to waive certain past
defaults under the Indenture and their consequences.

          14.  Restrictive Covenants.
               ---------------------

          The Indenture contains certain covenants which, among other things,
restrict the ability of the Company and Restricted Subsidiaries to incur
additional indebtedness (and, in the case of Restricted Subsidiaries, issue
preferred stock), pay dividends or make distributions in respect of the
Company's or Restricted Subsidiaries' capital stock, make other restricted
payments, enter into sale and leaseback transactions, incur liens, cause

                                      31
<PAGE>

encumbrances or restrictions to exist on the ability of Restricted Subsidiaries
to pay dividends or make distributions in respect of their capital stock, issue
and sell capital stock of Restricted Subsidiaries, enter into transactions with
affiliates, sell assets, or amalgamate, consolidate, merge or sell or otherwise
dispose of all or substantially all of their property and assets.

          15.  Defaults and Remedies.
               ---------------------

          With the exception of certain Events of Defaults specified below, if
an Event of Default occurs and is continuing, the Trustee or the Holders of not
less than 25% of the aggregate principal amount of the outstanding Notes may
declare the principal amount of, and any accrued and unpaid interest on, all
Notes then outstanding to be immediately due and payable.  If a bankruptcy or
insolvency default with respect to the Company or a Restricted Subsidiary occurs
and is continuing, the Notes immediately become due and payable.  Holders may
not enforce the Indenture or the Notes except as provided in the Indenture.  The
Trustee may require indemnity satisfactory to it before it enforces the
Indenture or the Notes.  Subject to certain limitations, Holders of not less
than a majority in principal amount of the outstanding Notes will have the right
to direct the time, method and place of conducting any proceeding for exercising
any remedy available to the Trustee.

          16.  No Recourse Against Others.
               --------------------------

          No controlling Person, director, officer, employee, incorporator or
stockholder of the Company, as such, shall have any liability for any covenant,
agreement or other obligations of the Company under the Notes or the Indenture
or for any claim based on, in respect of, or by reason of, such obligations or
their creation, solely by reason of its past, present or future status as a
controlling Person, director, officer, employee, incorporator or stockholder of
the Company.  Each Holder by accepting a Note waives and releases all such
liability (but only such liability).  The waiver and release are part of the
consideration for the issuance of the Notes.

          17.  Governing Law.
               -------------

          THIS SECURITY SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE LAWS OF THE STATE OF NEW YORK BUT WITHOUT GIVING EFFECT TO APPLICABLE
PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF
ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

          The Company will furnish to any Holder upon written request and
without charge to the Holder a copy of the Indenture.  Requests may be made to:

          Focal Communications Corporation
          200 N. LaSalle
          Chicago, Illinois 60601
          Attention:  Chief Financial Officer

          18.  Ranking.
               -------

          The Notes are senior unsecured obligations of the Company ranking pari
passu in right of payment with all existing and future senior indebtedness of
the Company, and will rank senior in right of payment to all existing and future
subordinated Indebtedness

                                      32
<PAGE>

of the Company. Holders of secured Indebtedness of the Company, however, will
have claims that are prior to the claims of the Holders with respect to the
assets securing such other indebtedness except to the extent the Notes are
equally and ratably secured by such assets.

                                      33
<PAGE>

____________________________________________________________

                            CERTIFICATE OF TRANSFER

To assign this Note, fill in the form below:

I or we assign and transfer this Note to

     (Print or type assignee's name, address and zip code)

     (Insert assignee's soc. sec. or tax I.D. No.)

and irrevocably appoint                           agent to transfer this Note on
the books of Focal Communications Corporation.  The agent may substitute another
to act for him.

_____________________________________________________________________

Date: ________________ Your Signature: _____________________

_____________________________________________________________________
Sign exactly as your name appears on the other side of this Note.

                                      34
<PAGE>

In connection with any transfer of any of the Notes evidenced by this
certificate occurring prior to the expiration of the period referred to in Rule
144(k) under the Securities Act of 1933 (the "Securities Act") after the later
of the date of original issuance of such Notes and the last date, if any, on
which such Notes were owned by Focal Communications Corporation or any
Affiliate, the undersigned confirms that such Notes are being transferred in
accordance with the terms of such Notes:

CHECK ONE BOX BELOW

     (1)  [_]  to Focal Communications Corporation; or

     (2)  [_]  pursuant to an effective registration statement under the
               Securities Act; or

     (3)  [_]  inside the United States to a "qualified institutional buyer"
               (as defined in Rule 144A under the Securities Act of 1933) that
               purchases for its own account or for the account of a qualified
               institutional buyer to whom notice is given that such transfer is
               being made in reliance on Rule 144A under the Securities Act, in
               each case pursuant to and in compliance with Rule 144A under the
               Securities Act; or

     (4)  [_]  outside the United States in an offshore transaction within the
               meaning of Regulation S under the Securities Act in compliance
               with Rule 904 under the Securities Act;

     (5)  [_]  pursuant to another available exemption from registration
               provided by Rule 144 under the Securities Act; or

     (6)  [_]  to an institution that is an "accredited investor" as defined in
               Rule 501(a)(1), (2), (3) or (7) under the Securities Act that is
               acquiring this Note for investment purposes and not for
               distribution in violation of the Securities Act or any other
               applicable securities laws.

     Unless one of the boxes is checked, the Trustee will refuse to register any
     of the Notes evidenced by this certificate in the name of any person other
     than the registered holder thereof; provided, however, that if box (3),
     (4), (5) or (6) is checked, the Trustee may require, prior to registering
     any such transfer of the Notes, such legal opinions, certifications and
     other information as the Company has reasonably requested to confirm that
     such transfer is being made pursuant to an exemption from, or in a
     transaction not subject to, the registration requirements of the Securities
     Act, such as the exemption provided by Rule 144 under the Securities Act.

                                      35
<PAGE>

_________________________
Signature

Signature Guarantee:

_________________________                ______________________________
[Signature must be guaranteed            Signature
by an eligible Guarantor
Institution (banks, stock
brokers, savings and loan
associations and credit
unions) with membership in
an approved guarantee
medallion program pursuant
to Securities and Exchange
Commission Rule 17Ad-15]

__________________________________________________________________

             TO BE COMPLETED BY PURCHASER IF (3) ABOVE IS CHECKED.

          The undersigned represents and warrants that it is purchasing this
Note for its own account or an account with respect to which it exercises sole
investment discretion and that it and any such account is a "qualified
institutional buyer" within the meaning of Rule 144A under the Securities Act,
and is aware that the sale to it is being made in reliance on Rule 144A under
the Securities Act and acknowledges that it has received such information
regarding the Company as the undersigned has requested pursuant to Rule 144A
under the Securities Act or has determined not to request such information and
that it is aware that the transferor is relying upon the foregoing
representations of the undersigned in order to claim the exemption from
registration provided by Rule 144A under the Securities Act.

Dated: ________________       ________________________________________________
                              NOTICE:  To be executed by an executive officer

                                      36
<PAGE>

                       [TO BE ATTACHED TO GLOBAL NOTES]

               SCHEDULE OF INCREASES OR DECREASES IN GLOBAL NOTE

   The following increases or decreases in this Global Note have been made:

<TABLE>
<CAPTION>
<S>                <C>                       <C>                       <C>                            <C>
                                                                        Principal Amount of this
                   Amount of decrease in     Amount of increase in     Global Note following such     Signature of authorized
 Date of             Principal Amount           Principal Amount              decrease or             signatory of Trustee or
 Exchange           of this Global Note       of this Global Note               increase                  Notes Custodian
 --------          ---------------------     ---------------------     --------------------------     ------------------------
</TABLE>

                                      37
<PAGE>

                      OPTION OF HOLDER TO ELECT PURCHASE

          If you want to elect to have this Note purchased by the Company
pursuant to Section 4.07 or 4.08 of the Indenture, check the box:

                              [__]

          If you want to elect to have only part of this Note purchased by the
Company pursuant to Section 4.07 or 4.08 of the Indenture, state the amount in
principal amount ($1,000 or an integral multiple thereof): $

Date: _______________    Your Signature: ___________________________________
                                         (Sign exactly as your name appears
                                         on the other side of this Note)

Signature Guarantee: _______________________________________
                     Signature must be guaranteed by an eligible Guarantor
                     Institution (banks, stock brokers, savings and loan
                     associations and credit unions) with membership in an
                     approved guarantee medallion program pursuant to Securities
                     and Exchange Commission Rule 17Ad-15]

          SECTION 2.04.  Form of Trustee's Certificate of Authentication. Harris
Trust and Savings Bank, as Trustee, certifies that this is one of the Notes
referred to in the within-mentioned Indenture.

     Date:

                                       HARRIS TRUST AND SAVINGS BANK,
                                          as Trustee

                                       by _____________________________
                                          Authorized Signatory

          SECTION 2.05.  Execution and Authentication.  (a) The aggregate
principal amount of Notes outstanding at any time shall not exceed $275,000,000
except as provided in Section 2.09.  The Notes shall be executed on behalf of
the Company by its Chief Executive Officer, Chief Financial Officer or, its
President or any Executive Vice President and shall be attested by the Company's
Corporate Secretary or one of its Assistant Secretaries, in each case by manual
or facsimile signature.

          (b)  The Notes shall be authenticated by manual signature of an
authorized officer of the Trustee and shall not be valid for any purpose unless
so authenticated.

          (c)  In case any officer of the Company whose signature shall have
been placed upon any of the Notes shall cease to be such officer of the Company
before authentication of such Notes by the Trustee and the issuance and delivery
thereof, such Notes may, nevertheless, be authenticated by the Trustee and
issued and delivered with

                                      38
<PAGE>

the same force and effect as though such Person had not ceased to be such
officer of the Company.

          (d)  Notwithstanding any other provision hereof, the Trustee shall
authenticate and deliver Notes only upon receipt by the Trustee of an Officers'
Certificate complying with Section 10.04 with respect to satisfaction of all
conditions precedent contained in this Indenture to authentication and delivery
of such Notes.

          (e)  Upon compliance by the Company with the provisions of paragraph
(d) of this Section 2.05, the Trustee shall authenticate and deliver: (1)
Original Notes for original issue in an aggregate principal amount of
$275,000,000 and (2) Exchange Notes for issue only in a Registered Exchange
Offer pursuant to the Registration Agreement, for a like principal amount of
Original Notes, in each case upon receipt of a Company Order.  Such Company
Order shall specify the amount of the Notes to be authenticated and the date on
which the original issue of Notes is to be authenticated and whether the Notes
are to be Original Notes or Exchange Notes.

          (f)  A Note shall not be valid or entitled to any benefit under this
Indenture or obligatory for any purpose unless executed by the Company and
authenticated by the manual signature of the Trustee as provided herein.  The
signature of an authorized officer of the Trustee shall be conclusive evidence,
and the only evidence, that such Note has been authenticated and delivered under
this Indenture.

          (g)  The Trustee may appoint an authenticating agent reasonably
acceptable to the Company to authenticate the Notes.  Unless limited by the
terms of such appointment, an authenticating agent may authenticate Notes
whenever the Trustee may do so.  Each reference in this Indenture to
authentication by the Trustee includes authentication by such agent.  Any
authenticating agent of the Trustee shall have the same rights hereunder as any
Note Registrar or Paying Agent. The Trustee, at its Corporate Trust Office, is
initially appointed authenticating agent hereunder.

          SECTION 2.06.  Note Registrar and Paying Agent.  (a) The Company shall
maintain, pursuant to Section 4.02, an office or agency where the Notes may be
presented for registration of transfer or for exchange, an office or agency
where Notes may be presented for payment and an office or agency where notices
and demands to or upon the Company in respect of the Notes and this Indenture
may be served.  The Company shall cause to be kept at such office a register
(the register maintained in such office being herein sometimes referred to as
the "Note Register") in which, subject to such reasonable regulations as it may
prescribe, the Company shall provide for the registration of Notes and of
transfers of Notes entitled to be registered or transferred as provided herein.
The Trustee, at its Corporate Trust Office, is initially appointed "Note
Registrar" for the purpose of registering Notes and transfers of Notes as herein
provided. The Company may, upon written notice to the Trustee, change the
designation of the Trustee as Note Registrar and appoint another Person to act
as Note Registrar for purposes of this Indenture.  If any Person other than the
Trustee acts as Note Registrar, the Trustee shall have the right at any time,
upon reasonable notice, to inspect or examine the Note Register and to make such
inquiries of the Note Registrar as the Trustee shall in its discretion deem
necessary or desirable in performing its duties hereunder.

          (b)  The Company shall enter into an appropriate agency agreement with
any Person designated by the Company as Note Registrar or Paying Agent that is

                                      39
<PAGE>

not a party to this Indenture, which agreement shall incorporate the provisions
of the Trust Indenture Act and shall implement the provisions of this Indenture
that relate to such Note Registrar or Paying Agent. Prior to the designation of
any such Person, the Company shall, by written notice (which notice shall
include the name and address of such Person), inform the Trustee of such
designation. If the Company fails to maintain a Note Registrar or Paying Agent,
the Trustee shall act as such. The Trustee, at its Corporate Trust Office, is
initially appointed Paying Agent hereunder.

          (c)  Upon surrender for registration of transfer of any Note at an
office or agency of the Company designated for such purpose, the Company shall
execute, and the Trustee shall authenticate and deliver, in the name of the
designated transferee or transferees, one or more new Original Notes or Exchange
Notes, as the case may be, of any authorized denomination or denominations, of
like tenor and aggregate principal amount, all as requested by the transferor.

          SECTION 2.07.  Paying Agent To Hold Money in Trust.  (a) The Company
will pay principal, premium, if any, and interest in money of the United States
that at the time of payment is legal tender for payment of public and private
debts.  On or prior to 10:00 a.m. on each due date of the principal, premium, or
any payment of interest [(including Defaulted Interest)] with respect to any
Note represented by a Global Note, the Company (through the Paying Agent) shall
make payment of a sum sufficient to pay such principal, premium or interest when
so becoming due in United States dollars by wire transfer of immediately
available funds to accounts specified by the Depositary.  With respect to
certificated Notes, the Company (through the Paying Agent) will make all
payments of principal, premium, interest [and Defaulted Interest], if any, by
wire transfer of immediately available funds in United States dollars to the
United States dollar accounts maintained by the Holders entitled thereto with
banks in the United States on or prior to 10:00 a.m. on each due date for
payment, or, if no such account is designated by any Holder to the Trustee or
the Paying Agent at least 30 days prior to the relevant due date for payment (or
such other date as the Trustee may accept in its discretion), by mailing a check
on such due date for payment to the registered address of the relevant Holder.
If a payment date is a date other than a Business Day at a place of payment,
payment may be made at that place on the next succeeding day that is a Business
Day and no interest shall accrue for the intervening period.

          (b)  The Company shall require each Paying Agent (other than the
Trustee) to agree in writing that such Paying Agent shall hold in trust for the
benefit of Holders or the Trustee all money held by such Paying Agent for the
payment of principal, premium or interest with respect to the Notes, shall
notify the Trustee of any default by the Company in making any such payment and
at any time during the continuance of any such default, upon the written request
of the Trustee, shall forthwith pay to the Trustee all sums held in trust by
such Paying Agent.

          (c)  The Company at any time may require a Paying Agent to pay all
money held by it to the Trustee and to account for any funds disbursed by such
Paying Agent.  Upon complying with this Section 2.07(c), the Paying Agent shall
have no further liability for the money delivered to the Trustee.

          SECTION 2.08.  Registration, Registration of Transfer and Exchange.
(a) At the option of the Holder, and subject to the other provisions of this
Section 2.08, Notes may be exchanged for other Notes of any authorized
denominations and of a like tenor and aggregate principal amount, upon surrender
of the Notes to be exchanged at an

                                      40
<PAGE>

office or agency maintained by the Company for such purpose pursuant to Section
4.02. Whenever any Notes are so surrendered for exchange, the Company shall
execute, and the Trustee shall authenticate and deliver, the Notes which the
Holder making the exchange is entitled to receive.

          (b)  All Notes issued upon any registration of transfer or exchange of
Notes shall be the valid obligations of the Company, evidencing the same debt,
and (subject to the provisions in the Original Notes and the Exchange Notes
regarding the payment of Additional Interest) entitled to the same benefits
under this Indenture, as the Notes surrendered upon such registration of
transfer or exchange.

          (c)  Every Note presented or surrendered for registration of transfer
or for exchange shall (if so required by the Company, the Trustee or the Note
Registrar) be duly endorsed, or be accompanied by a duly executed instrument of
transfer in form satisfactory to the Company, the Trustee and the Note
Registrar, by the Holder thereof or such Holder's attorney duly authorized in
writing.

          (d)  No service charge shall be made to the Holder for any
registration of transfer or exchange of Notes, but the Company may require
payment of a sum sufficient to cover any tax or other governmental charge that
may be imposed in connection with any registration of transfer or exchange of
Notes, other than exchanges pursuant to Sections 2.11, 3.06 or 9.06 or in
accordance with any offer pursuant to Sections 4.07 or 4.08.

          (e)  Any holder of beneficial ownership interests in a Global Note
shall, by acceptance of such Global Note, agree that transfers of beneficial
ownership interests in such Global Note may be effected through a book-entry
system maintained by the Holder of such Global Note (or its agent) and the
ownership of a beneficial ownership interest in the Global Note shall be
reflected in a book-entry.

          (f)  The Company shall not be required (i) to issue, register the
transfer of or exchange any Note during a period beginning at the opening of
business 15 calendar days before the day of the mailing of a notice of
redemption of Notes selected for redemption under Section 3.02 and ending at the
close of business on the day of such mailing, or (ii) to register the transfer
of or exchange any Note so selected for redemption in whole or in part, except
the unredeemed portion of any Note being redeemed in part.

          (g)  Certain Transfers and Exchanges.  Notwithstanding any other
provision of this Indenture or the Notes, transfers and exchanges of Notes and
beneficial ownership interests in a Global Note of the kinds specified in this
Section 2.08(g) shall be made only in accordance with this Section 2.08(g).

          (i)  Restricted Global Note to Regulation S Global Note.  If the owner
     of a beneficial ownership interest in the Restricted Global Note wishes at
     any time to transfer such interest to a Person who wishes to acquire the
     same in the form of a beneficial ownership interest in the Regulation S
     Global Note, such transfer may be effected only in accordance with the
     provisions of this clause (g)(i) and clause (g)(v) below and subject to the
     Applicable Procedures. Upon receipt by the Trustee, as Note Registrar, of
     (A) an order given by the Depositary or its authorized representative
     directing that a beneficial ownership interest in the Regulation S Global
     Note in a specified principal amount be

                                      41
<PAGE>

     credited to a specified Agent Member's account and that a beneficial
     ownership interest in the Restricted Global Note in an equal principal
     amount be debited from another specified Agent Member's account and (B) a
     Regulation S Certificate, in form satisfactory to the Trustee and duly
     executed by the owner of such beneficial ownership interest in the
     Restricted Global Note or his attorney duly authorized in writing, then the
     Trustee, as Note Registrar but subject to clause (g)(v) below, shall reduce
     the principal amount of the Restricted Global Note and increase the
     principal amount of the Regulation S Global Note by such specified
     principal amount as provided in Section 2.08(i)(iii).

          (ii)   Regulation S Global Note to Restricted Global Note.  If the
     owner of a beneficial ownership interest in the Regulation S Global Note
     wishes at any time to transfer such interest to a Person who wishes to
     acquire the same in the form of a beneficial ownership interest in the
     Restricted Global Note, such transfer may be effected only in accordance
     with this clause (g)(ii) and subject to the Applicable Procedures.  Upon
     receipt by the Trustee, as Note Registrar, of (A) an order given by the
     Depositary or its authorized representative directing that a beneficial
     ownership interest in the Restricted Global Note in a specified principal
     amount be credited to a specified Agent Member's account and that a
     beneficial ownership interest in the Regulation S Global Note in an equal
     principal amount be debited from another specified Agent Member's account
     and (B) if such transfer is to occur during the Restricted Period, a
     Restricted Notes Certificate, in form satisfactory to the Trustee and duly
     executed by the owner of such beneficial ownership interest in the
     Regulation S Global Note or his attorney duly authorized in writing, then
     the Trustee, as Note Registrar, shall reduce the principal amount of the
     Regulation S Global Note and increase the principal amount of the
     Restricted Global Note by such specified principal amount as provided in
     Section 2.08(i)(iii).

          (iii)  Non-Global Note to Non-Global Note.  A Note that is not a
     Global Note may be transferred, in whole or in part, to a Person who takes
     delivery in the form of another Note that is not a Global Note as provided
     in Section 2.08(a) hereof; provided that, if the Note to be transferred in
     whole or in part is a Restricted Note, or is a Regulation S Note and the
     transfer is to occur during the Restricted Period, then the Trustee shall
     have received (A) a Restricted Notes Certificate (or the completion of the
     Certificate of Transfer on the Note), in form satisfactory to the Trustee
     and duly executed by the transferor Holder or his attorney duly authorized
     in writing, in which case the transferee shall take delivery in the form of
     a Restricted Note, or (B) a Regulation S Certificate (or the completion of
     the Certificate of Transfer on the Note), in form satisfactory to the
     Trustee and duly executed by the transferor Holder or his attorney duly
     authorized in writing, in which case the transferee shall take delivery in
     the form of a Regulation S Note (subject in each case to Section 2.08(h)
     hereof).

          (iv)   Exchanges between Global Note and Non-Global Note.  A
     beneficial ownership interest in a Global Note may be exchanged for a Note
     that is not a Global Note as provided in Section 2.08(i)(ii); provided
     that, if such interest is a beneficial ownership interest in the Restricted
     Global Note, or if such interest is a beneficial ownership interest in the
     Regulation S Global Note and such exchange is to occur during the
     Restricted Period, then such interest shall be exchanged for a Restricted
     Note (subject in each case to Section 2.08(h)).

                                      42
<PAGE>

          (v)   Exchanges between Temporary Regulation S Global Notes and
     Permanent Regulation S Global Notes. Following the termination of the
     Restricted Period (which termination the Company shall notify the Trustee
     of pursuant to Section 4.18(c) hereof), beneficial ownership interests in
     the Temporary Regulation S Global Note may be exchanged for equivalent
     beneficial ownership interests in a permanent Global Note (a "Permanent
     Regulation S Global Note") in fully registered form, pursuant to the
     Applicable Procedures of the Depositary and only upon the receipt by the
     Trustee of a certificate substantially in the form of Annex D hereto to the
     effect that Euroclear or CEDEL, as the case may be, has received a
     certificate substantially in the form of Annex E hereto from the owner of
     such beneficial ownership interest in such Temporary Regulation S Global
     Note. The delivery to the Trustee by Euroclear or CEDEL of the certificate
     or certificates in the form of Annex D referred to above may be relied upon
     by the Company and the Trustee as conclusive evidence that the certificate
     or certificates referred to therein has or have been delivered to Euroclear
     or CEDEL pursuant to the terms of this Indenture. Upon receipt by the
     Trustee, as Note Registrar, of (A) such a certificate substantially in the
     form of Annex D hereto and (B) an order given by the Depositary or its
     authorized representative directing that the Temporary Regulation S Global
     Note be reduced by, and the Permanent Regulation S Global Note be increased
     by, the aggregate principal amount of the beneficial ownership interest in
     the Temporary Regulation S Global Note to be so exchanged and to credit or
     cause to be credited in the account of the Agent Member specified in such
     instructions a beneficial ownership interest in the Permanent Regulation S
     Global Note equal to the reduction in the aggregate principal amount of the
     Temporary Regulation S Global Note, then the Trustee, as Note Registrar,
     shall reduce the principal amount of the Temporary Regulation S Global Note
     and increase the principal amount of the Permanent Regulation S Global Note
     by such specified principal amount as provided in Section 2.08(i)(iii). The
     Company shall use its best efforts to cause the Depositary to ensure that,
     until the expiration of the Restricted Period, beneficial ownership
     interests in the Regulation S Global Note may be held only in or through
     accounts maintained at the Depositary by Euroclear or Cedel (or by Agent
     Members acting for the account thereof), and no person shall be entitled to
     effect any transfer or exchange that would result in any such interest
     being held otherwise than in or through such an account.

          (vi)  Notwithstanding any other provisions of this Indenture (other
     than the provisions set forth in Section 2.08(i)(iii)), a Global Note may
     not be transferred as a whole except by the Depositary to a nominee of the
     Depositary or by a nominee of the Depositary to the Depositary or another
     nominee of the Depositary or by the Depositary or any such nominee to a
     successor Depositary or a nominee of such successor Depositary.

          (h)   Securities Act Legends.  Rule 144A Notes and their Successor
Notes, and Regulation S Notes and their Successor Notes, shall each bear a
Securities Act Legend, subject to the following:

          (i)   subject to the following clauses of this Section 2.08(h), a new
     Note which is issued in exchange for another Note or any portion thereof,
     upon transfer or otherwise, shall bear a Securities Act Legend if such
     other Note bore a Securities Act Legend;

                                      43
<PAGE>

          (ii)   Exchange Notes shall not bear a Securities Act Legend;

          (iii)  at any time after the Notes may be freely transferred without
     registration under the Securities Act or without being subject to transfer
     restrictions pursuant to the Securities Act, a new Note which does not bear
     a Securities Act Legend may be issued in exchange for or in lieu of a Note
     or any portion thereof which bears such a legend if the Trustee has
     received an Unrestricted Note Certificate, in form satisfactory to the
     Trustee and duly executed by the Holder of such legended Note or his
     attorney duly authorized in writing, and after such date and receipt of
     such Unrestricted Note Certificate, the Trustee shall authenticate and
     deliver such a new Note in exchange for or in lieu of such other legended
     Note as provided in this Article II;

          (iv)   a new Note which does not bear a Securities Act Legend may be
     issued in exchange for or in lieu of a Note or any portion thereof which
     bears such a legend if, in the Company's judgment, placing such a legend
     upon such new Note is not necessary to ensure compliance with the
     registration requirements of the Securities Act, and the Trustee, at the
     direction of the Company, shall authenticate and deliver such a new Note as
     provided in this Article II; and

          (v)    notwithstanding the foregoing provisions of this Section
     2.08(h), a Successor Note of a Note that does not bear a particular form of
     Securities Act Legend shall not bear such form of legend unless the Company
     has reasonable cause to believe that such Successor Note is a "restricted
     security" within the meaning of Rule 144, in which case the Trustee, at the
     direction of the Company, shall authenticate and deliver a new Note bearing
     a Securities Act Legend in exchange for such Successor Note as provided in
     this Article II.

          (i)    The provisions of clauses (i), (ii), (iii), (iv) and (v) below
shall apply only to Global Notes:

          (i)    Each Global Note authenticated under this Indenture shall be
     registered in the name of the Depositary or a nominee thereof and delivered
     to the Depositary or a nominee thereof or custodian therefor, and each such
     Global Note shall constitute a single Note for all purposes of this
     Indenture.

          (ii)   Notwithstanding any other provision in this Indenture, no
     Global Note may be exchanged in whole or in part for Notes registered, and
     no transfer of a Global Note in whole or in part may be registered, in the
     name of any Person other than the Depositary or a nominee thereof unless
     (i) the Depositary notifies the Company that it is unwilling or unable to
     continue as a depositary for such Global Note or if at any time the
     Depositary ceases to be a clearing agency registered under the Exchange
     Act, and in either case a successor depositary is not appointed by the
     Company within 90 days, (ii) the Company executes and delivers to the
     Trustee a notice that such Global Note shall be so transferable,
     registrable and exchangeable, and such transfer shall be registrable or
     (iii) there shall have occurred and be continuing a Default with respect to
     the Notes represented by such Global Note.

          (iii)  If any Global Note is to be exchanged for other Notes or
     canceled in whole, it shall be surrendered by or on behalf of the
     Depositary or its nominee

                                      44
<PAGE>

     to the Trustee, as Note Registrar, for exchange or cancellation as provided
     in this Article II. If any Global Note is to be exchanged for other Notes
     or canceled in part, or if another Note is to be exchanged in whole or in
     part for a beneficial ownership interest in any Global Note, then either
     (A) such Global Note shall be so surrendered for exchange or cancellation
     as provided in this Article II or (B) the principal amount thereof shall be
     reduced by an amount equal to the portion thereof to be so exchanged for
     other Notes or canceled, or increased by an amount equal to the principal
     amount of such other Note to be so exchanged for a beneficial ownership
     interest therein, as the case may be, by means of an appropriate adjustment
     made on the records of the Trustee, as Note Registrar, whereupon the
     Trustee, in accordance with the Applicable Procedures, shall instruct the
     Depositary or its authorized representative to make a corresponding
     adjustment to its records. Upon any such surrender or adjustment of a
     Global Note, the Trustee shall, subject to Section 2.08(i)(ii) and as
     otherwise provided in this Article II, authenticate and deliver any Notes
     issuable in exchange for such Global Note (or any portion thereof) to or
     upon the order of, and registered in such names as may be directed by, the
     Depositary or its authorized representative. Upon the request of the
     Trustee in connection with the occurrence of any of the events specified in
     Section 2.08(i)(ii), the Company shall promptly make available to the
     Trustee a reasonable supply of Notes that are not in the form of Global
     Notes. The Trustee shall be entitled to rely upon any order, direction or
     request of the Depositary or its authorized agent which is given or made
     pursuant to this Article II if such order, direction or request is given or
     made in accordance with the Applicable Procedures.

          (iv)  Every Note authenticated and delivered upon registration of
     transfer of, or in exchange for or in lieu of, a Global Note or any portion
     thereof, whether pursuant to this Section, Section 2.09, 3.06, 4.07, 4.08
     or 9.06 or otherwise, shall be authenticated and delivered in the form of,
     and shall be, a Global Note, unless such Note is registered in the name of
     a Person other than the Depositary or a nominee thereof.

          (v)   None of the Company, the Trustee, any agent of the Trustee, any
     Paying Agent or the Note Registrar will have any responsibility or
     liability for any aspect of the Depositary's records (or the records of the
     Agent Members) relating to or payments made on account of beneficial
     ownership interests in a Global Note or for maintaining, supervising or
     reviewing any records of the Depositary relating to such beneficial
     ownership interests.

          SECTION 2.09.  Replacement Notes.  (a) If any mutilated Note is
surrendered to the Trustee, the Company shall execute and upon its written
request the Trustee shall authenticate and deliver, in exchange for any such
mutilated Note, a new Note containing identical provisions and of like principal
amount, bearing a number not contemporaneously outstanding.

          (b)   If there shall be delivered to the Company and the Trustee (i)
evidence to their satisfaction of the destruction, loss or theft of any Note and
(ii) such security or indemnity as may be required by them to save either of
them and any agent of each of them harmless, then, in the absence of notice to
the Company or the Trustee that such Note has been acquired by a bona fide
purchaser, the Company shall execute and upon its request the Trustee shall
authenticate and deliver, in lieu of any such destroyed,

                                      45
<PAGE>

lost or stolen Note, a new Note containing identical provisions and of like
principal amount, bearing a number not contemporaneously outstanding.

          (c)  In case any such mutilated, destroyed, lost or stolen Note has
become or is about to become due and payable, the Company in its discretion may,
instead of issuing a new Note, pay such Note.

          (d)  Upon the issuance of any new Note under this Section 2.09, the
Company may require the payment by the Holder of a sum sufficient to cover any
tax or other governmental charge that may be imposed in relation thereto and any
other expenses (including the fees and expenses of the Trustee) connected
therewith.

          (e)  Every new Note issued pursuant to this Section 2.09 in lieu of
any destroyed, lost or stolen Note shall constitute an original additional
contractual obligation of the Company, whether or not the destroyed, lost or
stolen Note shall be at any time enforceable by anyone, and shall be entitled to
all the benefits of this Indenture equally and proportionately with any and all
other Notes duly issued hereunder.

          (f)  The provisions of this Section 2.09 are exclusive and shall
preclude (to the extent lawful) all other rights and remedies with respect to
the replacement or payment of mutilated, destroyed, lost or stolen Notes.

          SECTION 2.10.  Outstanding Notes.  (a) Notes outstanding at any time
are all Notes authenticated by the Trustee except for those canceled by it,
those delivered to it for cancellation and those described in this Section 2.10
as not outstanding. A Note does not cease to be outstanding because the Company
or an Affiliate of the Company holds such Note.

          (b)  If a Note is replaced pursuant to Section 2.09, it ceases to be
outstanding unless the Trustee and the Company receive proof satisfactory to
them that such replaced Note is held by a bona fide purchaser.

          (c)  In determining whether the Holders of the required principal
amount of Notes have concurred in any direction, waiver or consent or any
amendment, modification or other change to this Indenture, Notes held or
beneficially owned by the Company or a Restricted Subsidiary or by an Affiliate
of the Company or a Restricted Subsidiary or by agents of any of the foregoing
shall be disregarded, except that for the purposes of determining whether the
Trustee shall be protected in relying on any such direction, waiver or consent
or any amendment, modification or other change to this Indenture, only Notes
which a Trust Officer knows are so owned shall be so disregarded.  Notes so
owned which have been pledged in good faith shall not be disregarded if the
pledgee establishes to the satisfaction of the Trustee such pledgee's right so
to act with respect to the Notes and that the pledgee is not the Company, a
Restricted Subsidiary or an Affiliate of either of them or any of their agents.

          SECTION 2.11.  Temporary Notes.  (a) Pending the preparation of
definitive Notes, the Company may execute, and the Trustee shall authenticate,
temporary notes ("Temporary Notes") which are printed or otherwise produced, of
like tenor of the definitive Notes in lieu of which they are issued and with
such appropriate insertions, omissions, substitutions and other variations.

                                      46
<PAGE>

          (b)  If Temporary Notes are issued, the Company shall cause definitive
Notes to be prepared without unreasonable delay.  After the preparation of
definitive Notes, the Temporary Notes shall be exchangeable for definitive Notes
upon surrender of the Temporary Notes to the Trustee, without charge to the
Holder.  Until so exchanged, Temporary Notes will evidence the same debt and
will be entitled to the same benefits under this Indenture as the definitive
Notes in lieu of which they have been issued.

          SECTION 2.12.  Cancellation.  The Company at any time may deliver
Notes to the Trustee for cancellation.  The Note Registrar and the Paying Agent
shall forward to the Trustee for cancellation any Notes surrendered to them for
registration of transfer, exchange, purchase or payment.  The Trustee shall
cancel all Notes surrendered for registration of transfer, exchange, purchase,
payment or cancellation and shall destroy such canceled Notes unless the Company
shall by Company Order otherwise direct.  The Company may not issue new Notes to
replace Notes that have been delivered to the Trustee for cancellation.

          SECTION 2.13.  Payment of Interest; Interest Rights Preserved.
                         ----------------------------------------------

          (a)  Interest on any Note which is payable, and is punctually paid or
duly provided for on any January 15 or July 15 on which Additional Interest is
due (an "Additional Interest Payment Date") shall be paid to the Person in whose
name such Note is registered at the close of business on the Regular Record Date
for such interest payment, which shall be the January 1 or July 1 (whether or
not a Business Day), as the case may be.

          (b)  Any interest on any Note which is payable, but is not punctually
paid or duly provided for, on any Additional Interest Payment Date (herein
called "Defaulted Interest") shall forthwith cease to be payable to the Holder
on the relevant Regular Record Date, and, except as hereinafter provided, such
Defaulted Interest, and any interest payable on such Defaulted Interest, may be
paid by the Company as provided in clause (i) below:

               (i)  The Company may elect to make payment of any Defaulted
     Interest, and any interest payable on such Defaulted Interest, to the
     Persons in whose names the Notes are registered at the close of business on
     a Special Record Date for the payment of such Defaulted Interest, which
     shall be fixed in the following manner. The Company shall notify the
     Trustee in writing of the amount of Defaulted Interest proposed to be paid
     on the Notes and the date of the proposed payment, and at the same time the
     Company shall deposit with the Trustee an amount in United States dollars
     equal to the aggregate amount proposed to be paid in respect of such
     Defaulted Interest or shall make arrangements satisfactory to the Trustee
     for such deposit prior to the date of the proposed payment, such United
     States dollars when deposited to be held in trust for the benefit of the
     Persons entitled to such Defaulted Interest as provided in this clause.
     Thereupon the Trustee shall fix a Special Record Date for the payment of
     such Defaulted Interest which shall be not more than 15 calendar days and
     not less than 10 calendar days prior to the date of the proposed payment
     and not less than 10 calendar days after the receipt by a Trust Officer of
     the Trustee of the notice of the proposed payment. The Trustee shall
     promptly notify the Company of such Special Record Date and, in the name
     and at the expense of the Company, shall cause notice of the proposed
     payment of such Defaulted

                                      47
<PAGE>

     Interest and the Special Record Date therefor to be sent, first class mail,
     postage prepaid, to each Holder at such Holder's address as it appears in
     the Note Register, not less than 10 calendar days prior to such Special
     Record Date. Notice of the proposed payment of such Defaulted Interest and
     the Special Record Date therefor having been mailed as aforesaid, such
     Defaulted Interest shall be paid to the Persons in whose names the Notes
     are registered at the close of business on such Special Record Date in the
     manner contemplated by Section 2.07(a).

          (c)  Subject to the foregoing provisions of this Section 2.13, each
Note delivered under this Indenture upon registration of transfer of, or in
exchange for, or in lieu of, any other Note, shall carry the rights to interest
accrued and unpaid, and to accrue, which were carried by such other Note.

          SECTION 2.14.  Authorized Denominations.  The Notes shall be issuable
in minimum denominations of $1,000 principal amount and any integral multiple
thereof.

          SECTION 2.15.  Computation of Interest.  Interest on the Notes shall
be computed on the basis of a 360-day year of twelve 30-day months; provided
that Additional Interest shall be computed on the basis of a 365- or 366-day
year, as the case may be, and the number of days actually elapsed from and
including the date Additional Interest commences to accrue to but excluding the
date on which Additional Interest ceases to accrue.

          SECTION 2.16.  Persons Deemed Owners.  Prior to the due presentation
for registration of transfer of any Note, the Company, the Trustee, the Paying
Agent and the Note Registrar may deem and treat the Person in whose name the
Note is registered as the owner of such Note for the purpose of receiving
payment of the principal of, premium, if any, and (subject to Section 2.13)
interest on such Note and for all other purposes whatsoever, whether or not such
Note is overdue, and none of the Company, the Trustee, the Paying Agent or the
Note Registrar shall be affected by notice to the contrary.

          SECTION 2.17.  CUSIP Numbers.  The Company, in issuing the Notes, may
use "CUSIP" and "ISIN" numbers for each series of Notes and, if so, the Trustee
shall use the relevant CUSIP and ISIN numbers in any notices to Holders as a
convenience to such Holders; provided that any such notice may state that no
representation is made as to the correctness or accuracy of the CUSIP and ISIN
numbers printed in the notice or on the Notes and that reliance may be placed
only on the other identification numbers printed on the Notes.  The Company
shall promptly notify the Trustee of any change in any CUSIP or ISIN numbers
used.

          SECTION 2.18.  Holder Lists.  The Trustee shall preserve in as current
a form as possible the most recent list available to it of the names and
addresses of Holders and shall otherwise comply with Trust Indenture Act ((S))
312(a). If the Trustee is not the Note Registrar, the Company shall furnish to
the Trustee as of each Regular Record Date and at such other times as the
Trustee may request in writing a list in such form and as of such date as the
Trustee may reasonably require of the names and addresses of Holders, including
the aggregate principal amount of Notes held by each Holder.

                                      48
<PAGE>

                                  ARTICLE III
                                  Redemption
                                  ----------

          SECTION 3.01.  Notice to Trustee.  If the Company elects to redeem
Notes pursuant to paragraph 5 of the Notes, it shall notify the Trustee in
writing of the Redemption Date and the principal amount of Notes to be redeemed.
The Company shall give each such notice to the Trustee at least 60 calendar days
prior to the Redemption Date unless the Trustee consents in writing to a shorter
period.  Such notice shall be accompanied by an Officers' Certificate and an
Opinion of Counsel from the Company to the effect that such redemption will
comply with any conditions to such redemption set forth herein and in the Notes.

          SECTION 3.02.  Selection of Notes To Be Redeemed.  Except as otherwise
provided herein, if less than all the Notes are to be redeemed at any time, the
Trustee shall select the Notes to be redeemed pro rata, by lot or such other
basis as it shall deem fair and appropriate; provided that the Trustee may
select for redemption in part only Notes in denominations larger than $1,000
principal amount.  In selecting Notes to be redeemed pursuant to this Section
3.02, the Trustee shall make such adjustments, reallocations and eliminations as
it shall deem  proper so that the principal amount of each Note to be redeemed
shall be $1,000 principal amount or an integral multiple thereof, by increasing,
decreasing or eliminating any amount less than $1,000 principal amount which
would be allocable to any Holder.  The Trustee in its discretion may determine
the particular Notes (if there are more than one) registered in the name of any
Holder which are to be redeemed, in whole or in part.  Provisions of this
Indenture that apply to Notes called for redemption also apply to portions of
Notes called for redemption.  The Trustee shall notify the Company promptly of
the Notes or portions of Notes to be redeemed.

          SECTION 3.03.  Notice of Redemption.  (a)  At least 30 calendar days
but not more than 60 calendar days before a Redemption Date, the Company shall
send a notice of redemption, first class mail, postage prepaid, to Holders of
Notes to be redeemed at the addresses of such Holders as they appear in the Note
Register.

          (b)    The notice shall identify the Notes to be redeemed and shall
state:

          (i)    the Redemption Date;

          (ii)   the Redemption Price (and shall specify the portion of such
     Redemption Price that constitutes the amount of accrued and unpaid interest
     to be paid, if any);

          (iii)  the name and address of the Paying Agent;

          (iv)   that the Notes called for redemption must be surrendered to the
     Paying Agent to collect the Redemption Price;

          (v)    if any Note is being redeemed in part, the portion of the
     principal amount of such Note to be redeemed and that, after the Redemption
     Date, a new Note or Notes in principal amounts equal to the unredeemed
     portion will be issued, or, if such Note is a Global Note, such Global
     Note, with a notation adjusting the principal amount thereof to be equal to
     the unredeemed portion, will be returned to the Holder thereof;

                                      49
<PAGE>

          (vi)    if fewer than all the outstanding Notes are to be redeemed,
     the identification and principal amounts of the particular Notes to be
     redeemed;

          (vii)   that, unless the Company defaults in making the redemption
     payment, interest on the Notes (or portions thereof) called for redemption
     shall cease and such Notes (or portions thereof) shall cease to accrue
     interest on and after the Redemption Date;

          (viii)  the paragraph of the Notes pursuant to which the Notes are
     being called for redemption;

          (ix)    the CUSIP or ISIN if applicable; and

          (x)     any other information necessary to enable Holders to comply
     with the notice of redemption.

          (c)     At the Company's request, the Trustee shall give the notice of
redemption in the Company's name and at the Company's expense.  In such event,
the Company shall provide the Trustee with the information required by this
Section 3.03 in a timely manner.

          SECTION 3.04.  Effect of Notice of Redemption.  Once notice of
redemption is mailed, Notes called for redemption shall become due and payable
on the Redemption Date and at the Redemption Price stated in such notice.  Upon
surrender to the Paying Agent, such Notes shall be paid at the Redemption Price
stated in such notice.  Failure to give notice or any defect in the notice to
any Holder shall not affect the validity of the notice to any other Holder.

          SECTION 3.05.  Deposit of Redemption Price.  (a)  Prior to 10:00 a.m.,
New York City time, on each Redemption Date, the Company shall deposit with the
Paying Agent (or, if the Company, one of its Subsidiaries or any of their
Affiliates is the Paying Agent, the Paying Agent shall segregate and hold in
trust for the benefit of the Holders) an amount of United States dollars in
immediately available funds, sufficient to pay the Redemption Price on all Notes
to be redeemed on that date other than Notes or portions of Notes called for
redemption on such date which have been delivered by the Company to the Trustee
for cancellation.  The Paying Agent shall make payment of the funds so deposited
or segregated in the manner contemplated by Section 2.07(a).

          (b)  So long as the Company complies with the preceding paragraph and
the other provisions of this Article III, interest on the Notes to be redeemed
on the applicable Redemption Date shall cease to accrue from and after such date
and such Notes or portions thereof shall be deemed not to be entitled to any
benefit under this Indenture except to receive payment of the Redemption Price
on the Redemption Date. If any Note called for redemption shall not be so paid
upon surrender for redemption, then, from the Redemption Date until such
principal, premium, if any, and accrued but unpaid interest is paid, interest
shall be paid on the unpaid principal and premium, if any, and, to the extent
permitted by law, on any accrued but unpaid interest thereon, in each case at
the rate prescribed therefor by such Notes.

          SECTION 3.06.  Notes Redeemed in Part.  Upon surrender and
cancellation of a Note (other than a Global Note) that is redeemed in part, the
Company shall issue and the Trustee shall authenticate and deliver to the
surrendering Holder (at

                                      50
<PAGE>

the Company's expense) a new Note equal in principal amount to the unredeemed
portion of the Note surrendered and canceled; provided that each such Note shall
be equal to $1,000 principal amount or an integral multiple thereof.

                                  ARTICLE IV

                                   Covenants
                                   ---------

          SECTION 4.01.  Payment of Notes.  (a)  The Company shall make all
payments in respect of Offer Purchase Price, principal amount, Redemption Price,
Change of Control Purchase Price, Change of Control Redemption Purchase Price,
accrued and unpaid interest, and Defaulted Interest, if any, on the Notes in
United States dollars in immediately available funds on the dates and in the
manner provided in the Notes and in this Indenture.  Principal, premium and
interest shall be considered paid on the date due if, on such date, the Trustee
or the Paying Agent (other than the Company, a Subsidiary of the Company or any
of their respective Affiliates) holds in accordance with this Indenture United
States dollars in immediately available funds designated for and sufficient to
pay all principal, premium and interest then due.

          (b)  The Company shall pay interest on overdue amounts due hereunder
and interest on overdue installments of interest, to the extent lawful, at a
rate per annum equal to the interest rate payable on the Notes.

          SECTION 4.02.  Maintenance of Office or Agency.  (a)   The Company
shall maintain an office in the Borough of Manhattan, the City of New York, or
agency where Notes may be presented or surrendered for payment, where Notes may
be surrendered for registration of transfer or exchange and where notices and
demands to or upon the Company in respect of the Notes and this Indenture may be
served.  The Company shall give prompt written notice to the Trustee of the
location, and any change in the location, of such office or agency.  If at any
time the Company shall fail to maintain any such required office or agency or
shall fail to furnish the Trustee with the address thereof, such presentations,
surrenders, notices and demands may be made or served at the office of Harris
Trust Company of New York, an affiliate of the Trustee located in the Borough of
Manhattan, the City of New York, and the Company hereby appoints the Trustee its
agent to receive all presentations, surrenders, notices and demands through such
affiliated office of the Trustee.

          (b)  The Company may also from time to time designate one or more
other offices or agencies (in or outside of the City of New York) where the
Notes may be presented or surrendered for any or all of such purposes, and may
from time to time rescind such designations; provided that no such designation
or rescission shall in any manner relieve the Company of its obligation to
maintain an office or agency in The City of New York, for such purposes.  The
Company shall give prompt written notice to the Trustee of any such designation
and any change in the location of any such other office or agency.

          SECTION 4.03.  Money for the Note Payments To Be Held in Trust. (a)
If the Company, any Subsidiary of the Company or any of their respective
Affiliates shall at any time act as Paying Agent with respect to the Notes, such
Paying Agent shall, on or before each due date of the principal of (and premium,
if any) or interest on any of the Notes, segregate and hold in trust for the
benefit of the Persons entitled thereto

                                      51
<PAGE>

United States dollars in immediately available funds designated for and
sufficient to pay the principal (and premium, if any) or interest so becoming
due until such funds shall be paid to such Persons or otherwise disposed of as
herein provided, and shall promptly notify the Trustee of its action or failure
so to act.

          (b)  Whenever the Company shall have one or more Paying Agents with
respect to the Notes, it shall, prior to or on each due date of the principal of
(and premium, if any) or interest on any of the Notes, deposit with a Paying
Agent United States dollars in immediately available funds designated for and
sufficient to pay the principal (and premium, if any) or interest so becoming
due, such funds to be held in trust for the benefit of the Persons entitled to
such principal, premium or interest, and (unless such Paying Agent is the
Trustee) the Paying Agent shall promptly notify the Trustee of the Company's
action or failure so to act.

          SECTION 4.04.  Corporate Existence.  Subject to the provisions of
Article IV and Article V hereof, the Company shall do or cause to be done all
things necessary to preserve and keep in full force and effect the corporate
existence, rights (charter and statutory) and franchises of the Company and each
of its Restricted Subsidiaries; provided that the Company and any such
Restricted Subsidiary shall not be required to preserve any such right or
franchise if the Board of Directors shall determine that the preservation
thereof is no longer desirable in the conduct of the business of the Company.

          SECTION 4.05.  Maintenance of Property.  The Company shall cause all
Property used or useful in the conduct of its business or the business of any of
its Restricted Subsidiaries and material to the Company and its Restricted
Subsidiaries taken as a whole to be maintained and kept in good condition,
repair and working order and supplied with all necessary equipment and shall
cause to be made all necessary repairs, renewals, replacements, betterments and
improvements thereof, all as, in the judgment of the Company, may be necessary
so that the business carried on in connection therewith may be properly and
advantageously conducted at all times; provided that nothing in this Section
4.05 shall prevent the Company from discontinuing the operation or maintenance
of any of such Property if such discontinuance is, in the judgment of management
of the Company, desirable in the conduct of its business or the business of any
of its Restricted Subsidiaries.

          SECTION 4.06.  Payment of Taxes and Other Claims.  The Company shall
pay or discharge or cause to be paid or discharged, before the same shall become
delinquent, (a) all material taxes, assessments and governmental charges levied
or imposed upon the Company or any of its Restricted Subsidiaries or upon the
income, profits or Property of the Company or any of its Restricted Subsidiaries
and (b) all material lawful claims for labor, materials and supplies which, if
unpaid, might become a Lien (other than a Permitted Lien) upon the Property of
the Company or any of its Restricted Subsidiaries; provided that the Company
shall not be required to pay or discharge or cause to be paid or discharged any
such tax, assessment, charge or claim whose amount, applicability or validity is
being contested in good faith by appropriate proceedings upon stay of execution
or the enforcement thereof and for which adequate reserves in accordance with
GAAP or other appropriate provision has been made.

          SECTION 4.07.  Repurchase at the Option of Holders upon a Change of
Control.  (a)   Upon the occurrence of a Change of Control, each Holder will
have the right to require the Company to repurchase all or any part (equal to
$1,000 principal

                                      52
<PAGE>

amount or an integral multiple thereof) of such Holder's Notes pursuant to the
offer described in Section 4.07(b) (the "Change of Control Offer") at a purchase
price (the "Change of Control Purchase Price") equal to 101% of the principal
amount thereof plus accrued and unpaid interest, if any, thereon to but
excluding any Change of Control Payment Date.

          (b)     Within 30 calendar days of the date of any Change of Control,
the Company, or the Trustee at the request and expense of the Company, shall
send to each Holder by first class mail, postage prepaid, a notice prepared by
the Company stating:

          (i)     that a Change of Control has occurred and a Change of Control
     Offer is being made pursuant to this Section 4.07, and that all Notes or
     portions thereof that are timely tendered will be accepted for payment;

          (ii)    the Change of Control Purchase Price, and the date Notes are
     to be purchased pursuant to the Change of Control Offer (the "Change of
     Control Payment Date"), which date shall be a date occurring no earlier
     than 30 calendar days nor later than 60 calendar days subsequent to the
     date such notice is mailed;

          (iii)   that any Notes or portions thereof not tendered or accepted
     for payment will continue to accrue interest;

          (iv)    that, unless the Company defaults in the payment of the Change
     of Control Purchase Price with respect thereto, all Notes or portions
     thereof accepted for payment pursuant to the Change of Control Offer shall
     cease to accrue interest from and after the Change of Control Payment Date;

          (v)     that any Holder electing to have any Notes or portions thereof
     purchased pursuant to a Change of Control Offer will be required to
     surrender such Notes, with the form entitled "Option of Holder to Elect
     Purchase" on the reverse of such Notes completed, to the Paying Agent at
     the address set forth in the notice, prior to the close of business on the
     third Business Day preceding the Change of Control Payment Date;

          (vi)    that any Holder shall be entitled to withdraw such election if
     the Paying Agent receives, not later than the close of business on the
     second Business Day preceding the Change of Control Payment Date, a
     telegram, telex, facsimile transmission or letter, setting forth the name
     of the Holder, the principal amount of Notes delivered for purchase, and a
     statement that such Holder is withdrawing such Holder's election to have
     such Notes or portions thereof purchased pursuant to the Change of Control
     Offer;

          (vii)   that any Holder electing to have Notes purchased pursuant to
     the Change of Control Offer must specify the principal amount that is being
     tendered for purchase, which amount must be $1,000 principal amount or an
     integral multiple thereof;

          (viii)  that any Holder whose Notes are being purchased only in part
     will be issued new Notes equal in principal amount to the unpurchased
     portion of the Note or Notes surrendered, which unpurchased portion must be
     equal to $1,000 principal amount or an integral multiple thereof, or, if
     such Note is a Global

                                      53
<PAGE>

     Note, such Global Note, with a notation adjusting the principal amount
     thereof to be equal to the unpurchased portion, will be returned to the
     Holder thereof;

          (ix)  that, if after giving effect to the Change of Control Offer, at
     least 95% of the original aggregate principal amount of the Notes has been
     redeemed or repurchased, the Company shall have the right to redeem the
     balance of the Notes at the Change of Control Redemption Purchase Price;
     and

          (x)   any other information necessary to enable any Holder to tender
     Notes and to have such Notes purchased pursuant to this Section 4.07(b).

          (c)   On the Change of Control Payment Date, the Company shall (i)
accept for payment any Notes or portions thereof properly tendered pursuant to
the Change of Control Offer; (ii) irrevocably deposit with the Paying Agent (or,
if the Company, one of its Subsidiaries or any of their Affiliates is the Paying
Agent, the Paying Agent shall segregate and hold in trust for the benefit of the
Holders), by 10:00 a.m., New York City time, on such date, in United States
dollars in immediately available funds, an amount equal to the Change of Control
Purchase Price in respect of all Notes or portions thereof so accepted other
than Notes or portions of Notes called for redemption on such date which have
been delivered by the Company to the Trustee for cancellation; and (iii)
deliver, or cause to be delivered, to the Trustee the Notes so accepted together
with an Officers' Certificate listing the Notes or portions thereof tendered to
the Paying Agent and accepted for payment.  The Paying Agent shall make payment
of the funds so deposited or segregated in the manner contemplated by Section
2.07(a).

          (d)   Upon surrender and cancellation of a Note (other than a Global
Note) that is purchased in part pursuant to the Change of Control Offer, the
Company shall execute and the Trustee shall promptly authenticate and deliver to
the surrendering Holder of such Note, a new Note equal in principal amount to
the unpurchased portion of such surrendered Note; provided that each such new
Note shall be equal to $1,000 principal amount or an integral multiple thereof.

          (e)   If after giving effect to a Change of Control Offer at least 95%
of the original aggregate principal amount of the Notes has been redeemed or
repurchased, the Company shall have the right to redeem the balance of the Notes
at a redemption price (the "Change of Control Redemption Purchase Price") equal
to 101% of the principal amount thereof plus accrued and unpaid interest, if
any, thereon to but excluding the date of redemption (the "Change of Control
Redemption Date") by sending (or, at the request and expense of the Company,
having the Trustee send) the Holders by first class mail, postage prepaid, a
notice prepared by the Company of such redemption within 30 calendar days of the
Change of Control Payment Date with respect to such Change of Control Offer (the
"Change of Control Redemption") stating:

          (i)   that a Change of Control Offer has been consummated and after
     giving effect thereto at least 95% of the original aggregate principal
     amount of the Notes has been redeemed or repurchased;

          (ii)  that the Company is exercising its right, pursuant to this
     Section 4.07(e), to redeem the balance of the outstanding Notes;

                                      54
<PAGE>

          (iii)  the Change of Control Redemption Date with respect to such
     Notes, which date shall be no earlier than 30 days nor later than 60 days
     from the date such notice is mailed;

          (iv)   that, unless the Company defaults in the payment of the Change
     of Control Redemption Purchase Price with respect to such Notes, all such
     Notes shall cease to accrue interest from and after such Change of Control
     Redemption Date;

          (v)    that all Holders are required to surrender such Notes to the
     Paying Agent at the address specified in the notice prior to the close of
     business on the third Business Day preceding the Change of Control
     Redemption Date to collect the Change of Control Redemption Purchase Price;
     and

          (vi)   such other matters as are required by Section 3.03.

          (f)    On the Change of Control Redemption Date, the Company shall:

          (i)    accept for payment Notes or portions thereon properly tendered
     pursuant to the Change of Control Redemption;

          (ii)   deposit with the Paying Agent (or, if the Company, one of its
     Subsidiaries or any of their Affiliates is the Paying Agent, the Paying
     Agent shall segregate and hold in trust for the benefit of the Holders), by
     10:00 a.m., New York City time, on such date, in United States dollars in
     immediately available funds, an amount equal to the Change of Control
     Redemption Purchase Price in respect of all Notes or portions thereof to be
     redeemed on that date; and

          (iii)  deliver, or cause to be delivered, to the Trustee the Notes so
     accepted together with an Officer's Certificate listing the Notes tendered
     to the Paying Agent and accepted for payment.

The Paying Agent shall make payment of the funds so deposited or segregated in
the manner contemplated by Section 2.07(a).

          (g)    To the extent such laws and regulations are applicable, the
Company shall comply with the requirements of Section 14(e) under the Exchange
Act and any other securities laws or regulations in connection with the
repurchase of Notes pursuant to a Change of Control Offer or a Change of Control
Redemption.

          SECTION 4.08.  Limitation on Asset Sales.  (a)  The Company shall not,
and shall not permit any of its Restricted Subsidiaries, directly or indirectly,
to, consummate any Asset Sale, unless:

          (i)    the Company or such Restricted Subsidiary, as the case may be,
     receives consideration for such Asset Sale at least equal to the Fair
     Market Value (as evidenced by a Board Resolution delivered to the Trustee)
     of the Property or other assets sold or otherwise disposed of;

          (ii)   at least 75% of the consideration received in respect of such
     Asset Sale by the Company or such Restricted Subsidiary, as the case may
     be, for such Property or other assets consists of (A) Cash Proceeds or
     Telecommunications

                                      55
<PAGE>

     Assets; or (B) the assumption of Indebtedness of the Company or such
     Restricted Subsidiary (other than Indebtedness that is subordinated by its
     terms to the Notes) and the release of the Company or the Restricted
     Subsidiary, as the case may be, from all liability on the Indebtedness
     assumed; or (C) publicly-traded shares of Capital Stock (other than
     Preferred Stock and Disqualified Stock) traded in the United States of any
     Person engaged in a Telecommunications Business; and

          (iii)  the Company or any Restricted Subsidiary, as the case may be,
     uses the Net Cash Proceeds from such Asset Sale in the manner set forth in
     Section 4.08(b).

          (b)    Within 360 calendar days after the closing of any Asset Sale,
the Company or any Restricted Subsidiary, as the case may be, may, at its
option, do any one or more of the following:

          (i)    reinvest an amount equal to the Net Cash Proceeds, or any
     portion thereof, from such Asset Sale in Telecommunications Assets or in
     Capital Stock of any Person engaged in the Telecommunications Business;

          (ii)   apply an amount equal to such Net Cash Proceeds (or remaining
     Net Cash Proceeds) (A) to the permanent reduction of senior secured
     Indebtedness of the Company (other than Indebtedness to a Restricted
     Subsidiary unless the proceeds thereof are used by such Restricted
     Subsidiary in a manner contemplated by clauses (i) through (iii) of this
     paragraph) or other Indebtedness of the Company (other than Indebtedness to
     a Restricted Subsidiary unless the proceeds thereof are used by such
     Restricted Subsidiary in a manner contemplated by clauses (i) through (iii)
     of this paragraph) that is senior to the Notes or to the permanent
     reduction of Indebtedness, or to the redemption of Preferred Stock, of any
     Restricted Subsidiary (other than Indebtedness to, or Preferred Stock owned
     by, the Company or another Restricted Subsidiary unless the proceeds
     thereof are used by the Company or such Restricted Subsidiary in a manner
     contemplated by clauses (i) through (iii) of this paragraph) or (B) to the
     extent none of the Company or any of its Restricted Subsidiaries has any
     Indebtedness outstanding of the type referred to in the immediately
     preceding clause (A) (other than Indebtedness under senior secured
     revolving credit facilities), to the repayment of outstanding Indebtedness
     under any such revolving credit facility; provided, however, that neither
     the Company nor any Restricted Subsidiary shall be required to permanently
     reduce the commitments under any such revolving credit facility by an
     amount equal to the outstanding Indebtedness thereunder so repaid or
     prepaid; or

          (iii)  apply an amount equal to such Net Cash Proceeds (or remaining
     Net Cash Proceeds) to prepay, whether in whole or in part, Indebtedness
     that is pari passu with the Notes and that matures prior to January 15,
     2010.

Net Cash Proceeds from any Asset Sale that are not used as described in clauses
(i) through (iii) above within 360 calendar days of the closing of such Asset
Sale shall constitute "Excess Proceeds."

          (c)    If on any date the aggregate amount of Excess Proceeds
calculated as of such date exceeds $5,000,000 on, the Company shall use the
then-existing Excess

                                      56
<PAGE>

Proceeds to make an offer, as described in Section 4.08(d) (an "Asset Sale
Offer"), to purchase on a pro rata basis (i) Notes at a purchase price (the
"Offer Purchase Price") in cash in United States dollars in immediately
available funds equal to 100% of the principal amount thereof, plus accrued and
unpaid interest thereon, if any, to but excluding the Asset Sale Payment Date
(as defined in Section 4.08(d)(ii)) and (ii) to the extent required by the terms
thereof, any other Indebtedness of the Company that is pari passu with the
Notes. The pro rata amount of such Excess Proceeds to be used to purchase Notes
shall be in an amount equal to the aggregate amount of such Excess Proceeds
multiplied by the quotient obtained by dividing the principal amount of the
outstanding Notes by the sum of such principal amount and the principal amount
of such other Indebtedness.

          (d)    Within 30 calendar days of the date on which the aggregate
amount of Excess Proceeds exceeds $5,000,000, the Company, or the Trustee at the
request and expense of the Company, shall send to each Holder by first class
mail, postage prepaid, a notice prepared by the Company stating:

          (i)    that an Asset Sale Offer is being made pursuant to this Section
     4.08, and that all Notes or portions thereof that are timely tendered will
     be accepted for payment, subject to proration in the event the amount of
     Excess Proceeds to be applied to repurchase Notes is less than the
     aggregate Offer Purchase Price of all Notes timely tendered pursuant to the
     Asset Sale Offer;

          (ii)   the Offer Purchase Price, the amount of Excess Proceeds that
     are available to be applied to purchase tendered Notes, and the date Notes
     or portions thereof are to be purchased pursuant to the Asset Sale Offer
     (the "Asset Sale Payment Date"), which date shall be a date no earlier than
     30 calendar days nor later than 60 calendar days subsequent to the date
     such notice is mailed;

          (iii)  that any Notes or portions thereof not tendered or accepted for
     payment will continue to accrue interest;

          (iv)   that, unless the Company defaults in the payment of the Offer
     Purchase Price with respect thereto, all Notes or portions thereof accepted
     for payment pursuant to the Asset Sale Offer shall cease to accrue interest
     from and after such Asset Sale Payment Date;

          (v)    that any Holder electing to have any Notes or portions thereof
     purchased pursuant to the Asset Sale Offer will be required to surrender
     such Notes, with the form entitled "Option of Holder to Elect Purchase" on
     the reverse of such Notes completed, to the Paying Agent at the address
     specified in the notice, prior to the close of business on the third
     Business Day preceding the Asset Sale Payment Date;

          (vi)   that any Holder shall be entitled to withdraw such election if
     the Paying Agent receives, not later than the close of business on the
     second Business Day preceding the Asset Sale Payment Date, a telegram,
     telex, facsimile transmission or letter, setting forth the name of the
     Holder, the principal amount of Notes delivered for purchase, and a
     statement that such Holder is withdrawing such Holder's election to have
     such Notes or portions thereof purchased pursuant to the Asset Sale Offer;

                                      57
<PAGE>

          (vii)   that any Holder electing to have Notes purchased pursuant to
     the Asset Sale Offer must specify the principal amount that is being
     tendered for purchase, which amount must be equal to $1,000 principal
     amount or an integral multiple thereof;

          (viii)  that any Holder whose Notes are being purchased only in part
     will be issued new Notes equal in principal amount to the unpurchased
     portion of the Note or Notes surrendered, which unpurchased portion will be
     equal to $1,000 principal amount or an integral multiple thereof, or, if
     such Note is a Global Note, such Global Note, with a notation adjusting the
     principal amount thereof to be equal to the unredeemed portion, will be
     returned to the Holder thereof; and

          (ix)    any other information necessary to enable any Holder to tender
     Notes and to have such Notes purchased pursuant to this Section 4.08.

          (e)     To the extent that the aggregate Offer Purchase Price of all
Notes tendered pursuant to an Asset Sale Offer is less than the Excess Proceeds
relating thereto (such shortfall constituting a "Deficiency"), upon completion
of such Asset Sale Offer (including payment of the Offer Purchase Price for
accepted Notes), the Company may use such Deficiency for general corporate
purposes and such Deficiency shall not thereafter constitute Excess Proceeds for
any purpose.

          (f)    In the event the aggregate principal amount of the outstanding
Notes tendered pursuant to an Asset Sale Offer is in excess of the Excess
Proceeds to be used to purchase such Notes as indicated in the notice required
by Section 4.08(d), the Trustee shall select the Notes to be purchased by such
Excess Proceeds on a pro rata basis, with such adjustments as may be deemed
appropriate by the Trustee, so that only Notes in principal amounts of $1,000 or
an integral multiple thereof shall be purchased. Any amount remaining after
giving effect to such purchase shall constitute a Deficiency and shall be
applied as provided in Section 4.08(e).

          (g)    On the Asset Sale Payment Date, the Company shall (i) accept
for payment any Notes or portions thereof properly tendered and selected for
purchase pursuant to the Asset Sale Offer and Section 4.08(f); (ii) irrevocably
deposit with the Paying Agent (or, if the Company, one of its Subsidiaries or
any of their Affiliates is the Paying Agent, the Paying Agent shall segregate
and hold in trust for the benefit of the Holders), by 10:00 a.m., New York City
time, on such date, in United States dollars in immediately available funds, an
amount equal to the Offer Purchase Price in respect of all Notes or portions
thereof so accepted other than Notes or portions of Notes called for redemption
on such date which have been delivered by the Company to the Trustee for
cancellation; and (iii) deliver, or cause to be delivered, to the Trustee the
Notes so accepted together with an Officers' Certificate listing the Notes or
portions thereof tendered to the Company and accepted for payment. The Paying
Agent shall make payment of the funds so deposited or segregated in the manner
contemplated by Section 2.07(a). The Company shall publicly announce the results
of the Asset Sale Offer on or as soon as practicable after the Asset Sale
Payment Date.

          (h)    Upon surrender and cancellation of a Note (other than a Global
Note) that is purchased in part, the Company shall execute and the Trustee shall
promptly authenticate and deliver to the surrendering Holder of such Note a new
Note equal in principal amount to the unpurchased portion of such surrendered
Note; provided

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that each such new Note shall be in a principal amount of $1,000 or an integral
multiple thereof.

          (i)    Upon completion of an Asset Sale Offer (including payment of
the Offer Purchase Price for accepted Notes), the amount of Excess Proceeds for
the purposes of the Notes and this Indenture shall be reset to zero.

          (j)    To the extent such laws and regulations are applicable, the
Company shall comply with the requirements of Section 14(e) under the Exchange
Act and any other securities laws or regulations in connection with the
repurchase of Notes pursuant to an Asset Sale Offer.

          SECTION 4.09.  Limitation on Consolidated Indebtedness.
                         ---------------------------------------

          (a)    The Company will not, and will not permit any Restricted
Subsidiary to, directly or indirectly, Incur any Indebtedness after the Issue
Date provided that the Company may Incur Indebtedness if, after giving effect to
the Incurrence of such Indebtedness and the receipt and application of the net
proceeds therefrom, the ratio of (A) the aggregate consolidated principal amount
of Indebtedness of the Company outstanding as of the most recent available
quarterly or annual balance sheet, after giving pro forma effect to the
Incurrence of such Indebtedness and any other Indebtedness Incurred since such
balance sheet date and the receipt and application of the proceeds thereof, to
(B) Consolidated Cash Flow Available for Fixed Charges for the four full fiscal
quarters immediately preceding the Incurrence of such Indebtedness for which
consolidated financial statements of the Company are available, determined on a
pro forma basis as if any such Indebtedness had been Incurred and the proceeds
thereof had been applied at the beginning of such four fiscal quarters, would be
less than 6.0 to 1.0 for such four-quarter periods.

          (b)    Notwithstanding the foregoing limitation, the Company and its
Restricted Subsidiaries may Incur each and all of the following:

          (i)    Senior Indebtedness in an aggregate principal amount
     outstanding at any one time not to exceed $250,000,000, and any renewal,
     extension, refinancing or refunding thereof in an amount which, together
     with any principal amount remaining outstanding or available pursuant to
     this clause (i) does not exceed the aggregate principal amount outstanding
     or available under all such Senior Indebtedness immediately prior to such
     renewal, extension, refinancing or refunding, less, in any case, any amount
     of such Indebtedness permanently repaid under Section 4.08;

          (ii)   Indebtedness (including Guarantees) Incurred to finance the
     cost (including the cost of design, development, acquisition, construction,
     installation, improvement, transportation or integration) to acquire
     equipment, inventory or network assets (including acquisitions by way of
     any Capital Lease Obligation and acquisitions of Capital Stock of a Person
     that becomes a Restricted Subsidiary to the extent of the Fair Market Value
     of the equipment, inventory or network assets so acquired) by the Company
     or a Restricted Subsidiary after the Issue Date;

          (iii)  Indebtedness owed by the Company to any Significant Restricted
     Subsidiary or Indebtedness owed by a Restricted Subsidiary to the Company
     or to

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<PAGE>

     a Significant Restricted Subsidiary; provided that upon either (A) the
     transfer or other disposition by a Significant Restricted Subsidiary or the
     Company of any Indebtedness so permitted to a Person other than the Company
     or a Significant Restricted Subsidiary or (B) the issuance (other than
     directors' qualifying shares), sale, transfer or other disposition of
     shares of Capital Stock (including by amalgamation, consolidation or
     merger) of a Significant Restricted Subsidiary (such that upon such sale,
     transfer or other disposition such Restricted Subsidiary would no longer
     meet the definition of a Significant Restricted Subsidiary) to a Person
     other than the Company or a Significant Restricted Subsidiary, the
     provisions of this clause (iii) shall no longer be applicable to such
     Indebtedness and such Indebtedness shall be deemed to have been Incurred at
     the time of such transfer or other disposition;

          (iv)  Indebtedness Incurred to renew, extend, refinance or refund
     (including successive extensions, renewals, refinancing and refundings),
     whether in whole or in part (each, a "refinancing") (A) the Notes, (B)
     Indebtedness outstanding at the date of this Indenture, (C) Indebtedness
     Incurred pursuant to clause (ii) of this Section 4.09(b) or (D)
     Indebtedness Incurred pursuant to Section 4.09(a), in an aggregate
     principal amount not to exceed the aggregate principal amount of the
     Indebtedness so refinanced plus the amount of any premium required to be
     paid in connection with such refinancing pursuant to the terms of the
     Indebtedness so refinanced or the amount of any premium reasonably
     determined by the Company as necessary to accomplish such refinancing by
     means of a tender offer or privately negotiated repurchase, plus the
     expenses of the Company and its Restricted Subsidiaries incurred in
     connection with such refinancing; provided that Indebtedness the proceeds
     of which are used to refinance the Notes or Indebtedness which is pari
     passu with the Notes or Indebtedness which is subordinate in right of
     payment to the Notes shall only be permitted under this clause (iv) if (Y)
     in the case of any refinancing of the Notes or Indebtedness which is pari
     passu with the Notes, the refinancing Indebtedness is made pari passu to
     the Notes or constitutes Subordinated Indebtedness, and, in the case of any
     refinancing of Subordinated Indebtedness, the refinancing Indebtedness
     constitutes Subordinated Indebtedness and (Z) in any case, the refinancing
     Indebtedness by its terms, or by the terms of any agreement or instrument
     pursuant to which such Indebtedness is issued, (1) does not provide for
     payments of principal of such Indebtedness at stated maturity or by way of
     a sinking fund applicable thereto or by way of any mandatory redemption,
     defeasance, retirement or repurchase thereof by the Company (including any
     redemption, retirement or repurchase which is contingent upon events or
     circumstances, but excluding any retirement required by virtue of the
     acceleration of any payment with respect to such Indebtedness upon any
     event of default thereunder), in each case prior to the time the same are
     required by the terms of the Indebtedness being refinanced and (2) does not
     permit redemption or other retirement (including pursuant to an offer to
     purchase made by the Company) of such Indebtedness at the option of the
     holder thereof prior to the time the same are required by the terms of the
     Indebtedness being refinanced, other than a redemption or other retirement
     at the option of the holder of such Indebtedness (including pursuant to an
     offer to purchase made by the Company) which is conditioned upon a change
     of control pursuant to provisions substantially similar to those described
     in Section 4.07(a) through (d);

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<PAGE>

          (v)     Indebtedness (A) in respect of performance, surety or appeal
     bonds provided in the ordinary course of business, (B) in respect of
     guarantees or letters of credit Incurred in the ordinary course of business
     or (C) arising from customary agreements providing for indemnification,
     adjustment of purchase price or similar obligations, or from guarantees or
     letters of credit, surety bonds or performance bonds securing any
     obligations of the Company or any of its Restricted Subsidiaries pursuant
     to such agreements, in the case of this clause (C) Incurred in connection
     with the disposition of any business, assets or Restricted Subsidiary
     (other than Guarantees of Indebtedness Incurred by any Person acquiring all
     or any portion of such business, assets or Restricted Subsidiary for the
     purpose of financing such acquisition);

          (vi)    Indebtedness outstanding under the Notes and this Indenture;

          (vii)   Subordinated Indebtedness in an aggregate principal amount
     outstanding at any one time not to exceed $100,000,000, less, in any case,
     any amount of such Indebtedness permanently repaid as provided under
     Section 4.08;

          (viii)  Indebtedness of the Company such that after giving effect to
     the incurrence thereof, the total aggregate principal amount of
     Indebtedness incurred under this clause (viii) plus any refinancings
     thereof otherwise incurred in compliance with the Indenture would not
     exceed 200% of Total Net Incremental Equity;

          (ix)    Acquired Indebtedness;

          (x)     Indebtedness of the Company to the extent the net proceeds
     thereof are promptly (A) used to repurchase Notes tendered as a result of a
     Change of Control Offer or (B) deposited to defease the Notes as provided
     under Article VIII;

          (xi)    Indebtedness not otherwise permitted to be Incurred pursuant
     to clauses (i) through (x) above, which, together with any other
     outstanding Indebtedness Incurred pursuant to this clause (xi), will not
     exceed $25,000,000 aggregate principal amount at any one time outstanding;
     and

          (xii)   Indebtedness of the Company and any Restricted Subsidiary
     outstanding on the Issue Date including without limitation, the 12.125%
     Senior Discount Notes due 2008 issued by the Company February 18, 1998.

          (c)  For purposes of determining any particular amount of Indebtedness
under this Section 4.09, (i) Guarantees, Liens or obligations with respect to
letters of credit supporting Indebtedness otherwise included in the
determination of such particular amount shall not be included and (ii) any Liens
granted pursuant to the equal and ratable provisions referred to in Section 4.12
shall not be treated as Indebtedness. For purposes of determining compliance
with this Section 4.09, in the event that an item of Indebtedness meets the
criteria of more than one of the types of Indebtedness described in the above
clauses, the Company, in its sole discretion, shall classify such item of
Indebtedness and only be required to include the amount and type of such
Indebtedness in one of such clauses; provided, however, that the Company may
allocate portions of such Indebtedness between or among such clauses.

                                      61
<PAGE>

          SECTION 4.10.  Reserved.
                         --------

          SECTION 4.11.  Limitation on Restricted Payments. (a)  The Company
will not, and will not permit any of its Restricted Subsidiaries to, directly or
indirectly, make any Restricted Payment unless, at the time of and after giving
effect to such proposed Restricted Payment:

          (i)    no Default or Event of Default shall have occurred and be
     continuing or shall occur as a consequence thereof;

          (ii)   after giving effect, on a pro forma basis, to such Restricted
     Payment and the Incurrence of any Indebtedness the net proceeds of which
     are used to finance such Restricted Payment, the Company could Incur at
     least $1.00 of additional Indebtedness pursuant to Section 4.09(a); and

          (iii)  after giving effect to such Restricted Payment on a pro forma
     basis, the aggregate amount expended (the amount so expended, if other than
     cash, to be determined in good faith by a majority of the disinterested
     members of the Board of Directors, whose determination shall be conclusive
     and evidenced by a Board Resolution) or declared for all Restricted
     Payments after the Issue Date does not exceed the sum of (A) 50% of the
     Consolidated Net Income of the Company (or, if Consolidated Net Income
     shall be a deficit, minus 100% of such deficit) for the period (taken as
     one accounting period) beginning on the last day of the fiscal quarter
     immediately preceding the Issue Date and ending on the last day of the
     fiscal quarter for which the Company's financial statements are available
     immediately preceding the date of such Restricted Payment, plus (B) 100% of
     the net reduction in Investments, subsequent to the Issue Date, in any
     Person, resulting from payments of interest on Indebtedness, dividends,
     repayments of loans or advances, or other transfers of Property (but only
     to the extent such interest, dividends, repayments or other transfers of
     Property are not included in the calculation of Consolidated Net Income),
     in each case to the Company or any Restricted Subsidiary from any Person
     (including from Unrestricted Subsidiaries) or from redesignations of
     Unrestricted Subsidiaries as Restricted Subsidiaries (valued in each case
     as provided in the definition of "Investment"), not to exceed in the case
     of any Person the amount of Investments previously made subsequent to the
     Issue Date by the Company or any Restricted Subsidiary in such Person and
     which was treated as a Restricted Payment, plus (C) the aggregate Net Cash
     Proceeds received after the Issue Date (X) as capital contributions to the
     Company, (Y) from the issuance (other than to a Subsidiary of the Company)
     of Capital Stock (other than Disqualified Stock) of the Company and
     warrants, rights or options on Capital Stock (other than Disqualified
     Stock) of the Company, or (Z) from the conversion of Indebtedness of the
     Company into Capital Stock (other than Disqualified Stock and other than by
     a Subsidiary of the Company) of the Company after the date of this
     Indenture, less, in the case of this clause (C), an amount equal to the
     amount of such Net Cash Proceeds that are used to Incur Indebtedness
     pursuant to Section 4.09(b)(vii) or to make Restricted Payments under
     Section 4.11(b)(ii) or (vi).

          (b)  The foregoing limitations shall not prevent the Company from:

          (i)  paying a dividend on its Capital Stock at any time within 60 days
     after the declaration thereof if, on the declaration date, the Company
     could have paid such dividend in compliance with Section 4.11(a);

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<PAGE>

          (ii)    retiring (A) any Capital Stock of the Company or (B) any
     Indebtedness of the Company that is subordinate in right of payment to the
     Notes, in exchange for, or out of the proceeds of the substantially
     concurrent sale of Qualified Stock of the Company;

          (iii)   retiring any Indebtedness of the Company subordinated in right
     of payment to the Notes in exchange for, or out of the proceeds of, the
     substantially concurrent Incurrence of Indebtedness of the Company (other
     than Indebtedness to a Subsidiary of the Company), provided that such new
     Indebtedness (A) is subordinated in right of payment to the Notes at least
     to the same extent as the Indebtedness being refinanced, (B) has an Average
     Life longer than the Notes, and (C) has no scheduled principal payments due
     in any amount earlier than the equivalent amount of principal under the
     Indebtedness so retired;

          (iv)    retiring any Capital Stock or options to acquire Capital Stock
     of the Company held by any directors, officers or employees of the Company
     or any Restricted Subsidiary upon the termination of such Person's tenure
     as a director or employee, as the case may be; provided that the aggregate
     price paid for all such retired Capital Stock or options shall not exceed
     $5,000,000 in the aggregate;

          (v)     retiring any Capital Stock of the Company to the extent
     necessary (as determined in good faith by a majority of the disinterested
     members of the Board of Directors, whose determination shall be conclusive
     and evidenced by a Board Resolution) to prevent the loss, or to secure the
     renewal or reinstatement, of any license or franchise held by the Company
     or any Restricted Subsidiary from any governmental agency;

          (vi)    Investments in a Person the primary business of which is
     related, ancillary or complimentary to the business of the Company and its
     Restricted Subsidiaries on the date of such Investments; provided, that the
     aggregate amount of Investments made pursuant to this clause (vi) does not
     exceed the sum of (A) $20,000,000 plus (B) an amount equal to (x) Total Net
     Incremental Equity, minus (y) any amount of Total Net Incremental Equity to
     the extent it has been used to incur Indebtedness pursuant to Section
     4.09(b)(viii);

          (vii)   the declaration or payment of dividends on the Common Stock of
     the Company (so long as such dividends are paid to the holders of all
     classes of Common Stock (following a Public Equity Offering of such Common
     Stock of up to 6% per annum of the Net Cash Proceeds received by the
     Company in such Public Equity Offering; and

          (viii)  payments or distributions to dissenting stockholders pursuant
     to applicable law to the extent required in connection with a
     consolidation, merger or transfer of assets that complies with the
     provisions of the Indenture applicable to mergers, consolidations and
     transfers of all or substantially all of the property and assets of the
     Company;

          (ix)    making Investments not otherwise permitted in an aggregate
     amount not to exceed $10,000,000 at any one time outstanding.

                                      63
<PAGE>

          (c)    In determining the amount of Restricted Payments permissible
under this Section 4.11, amounts expended pursuant to clauses (ii) and (iii) of
Section 4.11(b) hereof shall not be included as Restricted Payments.

          (d)    Not later than the date of making any Restricted Payment
(including any Restricted Payment permitted to be made pursuant to Section
4.11(b) or Section 4.11(c)), the Company shall deliver to the Trustee an
Officers' Certificate stating that such Restricted Payment is permitted and
setting forth the basis upon which the required calculations were computed,
which calculations may be based upon the Company's latest available financial
statements.

          SECTION 4.12.  Limitation on Liens.  (a)  The Company may not, and may
not permit any Restricted Subsidiary to, directly or indirectly, Incur or suffer
to exist any Lien on or with respect to any Property or other assets or
interests therein now owned or hereafter acquired or any income or profits
therefrom or any interest thereon to secure any Indebtedness without making, or
causing such Restricted Subsidiary to make, effective provision for securing the
Notes equally and ratably with such Indebtedness, provided that no Indebtedness
of the Company which is subordinate in right of payment to the Notes may be so
secured.

          (b)    The foregoing restrictions shall not apply to:

          (i)    Liens existing on the date of this Indenture and securing
     Indebtedness outstanding on the date of this Indenture;

          (ii)   Liens Incurred on or after the Issue Date pursuant to Section
     4.09(b)(i);

          (iii)  Liens in favor of the Company or any Significant Restricted
     Subsidiary;

          (iv)   Liens on Property of the Company or a Restricted Subsidiary
     acquired, constructed or constituting improvements made after the Issue
     Date to secure Indebtedness Incurred pursuant to Section 4.09(b)(ii) which
     is otherwise permitted under this Indenture, provided that (A) the
     principal amount of any Indebtedness secured by any such Lien does not
     exceed 100% of such purchase price or cost of construction or improvement
     of the Property subject to such Lien, (B) such Lien attaches to such
     Property prior to, at the time of or within 180 days after the engineering,
     acquisition, installation, development, improvement, completion of
     construction or commencement of operation of such Property and (C) such
     Lien does not extend to or cover any Property other than the specific item
     of Property (or portion thereof) acquired, engineered, constructed,
     installed, developed or constituting the improvements made with the
     proceeds of such Indebtedness;

          (v)    Liens to secure Acquired Indebtedness, provided that (A) such
     Lien attaches to the acquired asset prior to the time of the acquisition of
     such asset and (B) such Lien does not extend to or cover any other
     Property;

          (vi)   Liens to secure Indebtedness Incurred to extend, renew,
     refinance or refund (or successive extensions, renewals, refinancings or
     refundings), in whole or in part, Indebtedness secured by any Lien referred
     to in clauses (i), (ii), (iv) and (v) of this paragraph so long as such
     Lien does not extend to any other

                                      64
<PAGE>

     Property and the principal amount of Indebtedness so secured is not
     increased except as otherwise permitted under Section 4.09(b)(iv);

          (vii)   Liens not otherwise permitted by the foregoing clauses (i)
     through (vi) in an aggregate amount not to exceed 5% of the Company's
     Consolidated Tangible Assets as of the date on which any such Lien arises;

          (viii)  Liens granted after the Issue Date pursuant to Section 4.12(a)
     to secure the Notes; and

          (ix)    Permitted Liens.

          SECTION 4.13.  Limitation on Sale and Leaseback Transactions.  The
Company will not, and will not permit any of its Restricted Subsidiaries to,
directly or indirectly, enter into, assume, Guarantee or otherwise become liable
with respect to any Sale and Leaseback Transaction (other than a Sale and
Leaseback Transaction between the Company or a Restricted Subsidiary on the one
hand and a Restricted Subsidiary or the Company on the other hand), unless (a)
the Company or such Restricted Subsidiary, as the case may be, receives
consideration at the time of such Sale and Leaseback Transaction at least equal
to the Fair Market Value (as evidenced by a Board Resolution) of the Property
subject to such transaction, (b) the Attributable Indebtedness of the Company or
such Restricted Subsidiary with respect thereto is included as Indebtedness and
would be permitted by Section 4.09, (c) the Company or such Restricted
Subsidiary would be permitted to create a Lien on such Property without securing
the Notes by Section 4.12 and (d) the Net Cash Proceeds from such transaction
are applied in accordance with Section 4.08.

          SECTION 4.14.  Limitation on Dividends and Other Payment Restrictions
Affecting Subsidiaries.  (a)  The Company will not, and will not permit any
Restricted Subsidiary to, directly or indirectly, cause or suffer to exist or
become effective, or enter into, any encumbrance or restriction (other than
pursuant to law or regulation) on the ability of any Restricted Subsidiary (i)
to pay dividends or make any other distributions in respect of its Capital Stock
or pay any Indebtedness or other obligation owed to the Company or any
Restricted Subsidiary, (ii) to make loans or advances to the Company or any
Restricted Subsidiary or (iii) to transfer any of its Property to the Company or
any other Restricted Subsidiary, except:

          (A)  any encumbrance or restriction existing as of the Issue Date;

          (B)  any encumbrance or restriction pursuant to an agreement relating
     to an acquisition of Property, so long as the encumbrances or restrictions
     in any such agreement relate solely to the Property so acquired;

          (C)  any encumbrance or restriction relating to any Indebtedness of
     any Restricted Subsidiary existing on the date on which such Restricted
     Subsidiary is acquired by the Company or another Restricted Subsidiary
     (other than any such Indebtedness Incurred by such Restricted Subsidiary in
     connection with or in anticipation of such acquisition);

          (D)  any encumbrance or restriction pursuant to an agreement effecting
     a permitted refinancing of Indebtedness issued pursuant to an agreement
     referred to in the foregoing clauses (A) through (C), so long as the
     encumbrances and

                                      65
<PAGE>

          restrictions contained in any such refinancing agreement are not
          materially more restrictive than the encumbrances and restrictions
          contained in such agreements;

               (E)  in the case of clause (iii) above only, customary provisions
          (X) that restrict the subletting, assignment or transfer of any
          Property or other asset that is a lease, license, conveyance or
          contract or similar Property or other asset, (Y) existing by virtue of
          any transfer of, agreement to transfer, option or right with respect
          to, or Lien on, any Property or other assets of the Company or any
          Restricted Subsidiary not otherwise prohibited by this Indenture or
          (Z) arising or agreed to in the ordinary course of business, not
          relating to any Indebtedness, and that do not, individually or in the
          aggregate, detract from the value of Property or other assets of the
          Company or any Restricted Subsidiary in any manner material to the
          Company or any Restricted Subsidiary;

               (F)  in the case of clause (iii) above only, restrictions
          contained in any security agreement (including a Capital Lease
          Obligation) securing Indebtedness of the Company or a Restricted
          Subsidiary otherwise permitted under this Indenture, but only to the
          extent such restrictions restrict the transfer of the Property subject
          to such security agreement;

               (G)  any encumbrance or restriction pursuant to a Senior
          Indebtedness which is permitted to be outstanding under clause (i) of
          Section 4.09(b);

               (H)  in the case of clause (iii) above only, any encumbrance or
          restriction pursuant to an agreement for Indebtedness that is
          permitted to be outstanding under clause (ii) of Section 4.09(b); and

               (I)  any restriction with respect to a Restricted Subsidiary
          imposed pursuant to an agreement which has been entered into for the
          sale or disposition of all or substantially all of the Capital Stock
          or assets of such Restricted Subsidiary, provided that the
          consummation of such transaction would not result in a Default, that
          such restriction terminates if such transaction is not consummated and
          that the consummation or abandonment of such transaction occurs within
          one year of the date such agreement was entered into.

               (b)  The foregoing limitations shall not prevent the Company or
     any Restricted Subsidiary from (i) creating, incurring, assuming or
     suffering to exist any Liens otherwise permitted under Section 4.12 or (ii)
     restricting the sale or other disposition of Property or other assets of
     the Company or any of its Restricted Subsidiaries that secure Indebtedness
     of the Company or any of its Restricted Subsidiaries otherwise permitted
     under Section 4.09.

               SECTION 4.15. Limitation on Issuance and Sale of Capital Stock of
     Restricted Subsidiaries. The Company will not sell, and will not permit any
     Restricted Subsidiary, directly or indirectly, to issue or sell, any shares
     of Capital Stock of a Restricted Subsidiary (including options, warrants or
     other rights to purchase shares of such Capital Stock) except (a) to the
     Company or a Wholly Owned Restricted Subsidiary; (b) issuance of directors'
     qualifying shares or sales to foreign nationals of shares of Capital Stock
     of foreign Restricted Subsidiaries, to the extent required by applicable
     law; (c) if, immediately after giving effect to such issuance or sale, such
     Restricted Subsidiary would no longer constitute a Restricted Subsidiary
     and any Investment in such Person remaining after giving effect to such
     issuance or sale would have been permitted to be made under Section 4.11 if
     made on the date of such issuance

                                      66
<PAGE>

     or sale; or (d) issuances or sales of Common Stock (other than Disqualified
     Stock) of a Restricted Subsidiary, provided that the Company or such
     Restricted Subsidiary applies the Net Cash Proceeds, if any, of any such
     sale in accordance with Section 4.08.

               SECTION 4.16. Transactions with Affiliates. The Company will not,
     and will not permit any of its Restricted Subsidiaries to, directly or
     indirectly, sell, lease, transfer, or otherwise dispose of, any of its
     Properties or assets to, or purchase any Property or other assets from, or
     enter into any contract, agreement, understanding, loan, advance or
     Guarantee with or for the benefit of, any Affiliate (each of the foregoing,
     an "Affiliate Transaction"), unless (a) such Affiliate Transaction or
     series of related Affiliate Transactions is on terms that are no less
     favorable to the Company or such Restricted Subsidiary than those that
     could have been obtained in a comparable arm's-length transaction by the
     Company or such Restricted Subsidiary with a Person that is not an
     Affiliate (or, in the event that there are no comparable transactions
     involving Persons who are not Affiliates of the Company or the relevant
     Restricted Subsidiary to apply for comparative purposes, is otherwise on
     terms that, taken as a whole, the Company has determined to be fair to the
     Company or the relevant Restricted Subsidiary) and (b) the Company delivers
     to the Trustee (i) with respect to any Affiliate Transaction involving
     aggregate payments or, in the case of assets or Property, a Fair Market
     Value in excess of $1,000,000, a certificate of the chief executive,
     operating or financial officer of the Company evidencing such officer's
     determination that such Affiliate Transaction or series of related
     Affiliate Transactions complies with clause (a) above and is in the best
     interests of the Company or such Restricted Subsidiary, (ii) with respect
     to any Affiliate Transaction or series of related Affiliate Transactions
     involving aggregate payments or, in the case of assets or Property, a Fair
     Market Value in excess of $5,000,000, a Board Resolution certifying that
     such Affiliate Transaction or series of related Affiliate Transactions
     complies with clause (a) above and that such Affiliate Transaction or
     series of related Affiliate Transactions has been approved by a majority of
     the disinterested members of the Board of Directors who have determined
     that such Affiliate Transaction or series of related Affiliate Transactions
     is in the best interest of the Company or such Restricted Subsidiary and
     (iii) with respect to any Affiliate Transaction or series of related
     Affiliate Transactions involving aggregate payments or, in the case of any
     assets or Property, a Fair Market Value in excess of $10,000,000, a written
     opinion stating that the transaction complies with clause (a) above from a
     financial point of view from an investment banking firm of national
     standing in the United States which, in the good faith judgment of the
     Board of Directors, is independent with respect to the Company and its
     Subsidiaries and qualified to perform such task; provided that the
     following shall not be deemed Affiliate Transactions:

               (A)  any employment, non-competition, confidentiality or similar
          agreement entered into by the Company or any of its Restricted
          Subsidiaries in the ordinary course of business;

               (B)  any agreement or arrangement with respect to the
          compensation of a director or officer of the Company or any Restricted
          Subsidiary approved by a majority of the disinterested members of the
          Board of Directors;

               (C)  transactions permitted by Section 4.11;

               (D)  transactions pursuant to any agreement or arrangement
          existing on the Issue Date, including any renewal, replacement,
          extension, amendment or other modification thereof, provided such
          modifications are not materially more adverse to the Company or the
          Restricted Subsidiaries;

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<PAGE>

               (E)  issuances of Capital Stock of the Company to any Affiliates;
          and

               (F)  the sale of telecommunications services to any Affiliate on
          an arm's-length basis which is undertaken in the ordinary course of
          the Company's business.

               SECTION 4.17. Restricted and Unrestricted Subsidiaries. (a) The
     Company may designate a Subsidiary (including a newly formed or newly
     acquired Subsidiary) of the Company or any of its Restricted Subsidiaries
     as an Unrestricted Subsidiary if such Subsidiary does not have any
     obligations which, if in default, would result in a cross default on
     Indebtedness of the Company or a Restricted Subsidiary (other than
     Indebtedness to the Company or a Significant Restricted Subsidiary), and
     (i) such Subsidiary has total assets of $1,000 or less, (ii) such
     Subsidiary has assets of more than $1,000 and an Investment in such
     Subsidiary in an amount equal to the Fair Market Value of such Subsidiary
     would then be permitted under Section 4.11(a) or (iii) such designation is
     effective immediately upon such Person becoming a Subsidiary. Unless so
     designated as an Unrestricted Subsidiary, any Person that becomes a
     Subsidiary of the Company shall be classified as a Restricted Subsidiary
     thereof.

               (b)  The Company may designate any Unrestricted Subsidiary to be
     a Restricted Subsidiary; provided that (i) no default or Event of Default
     shall have occurred and be continuing at the time of or after giving effect
     to such designation and (ii) all Liens and Indebtedness of such
     Unrestricted Subsidiary outstanding immediately after such designation
     would, if Incurred at such time, have been permitted to be Incurred (and
     shall be deemed to have been Incurred) for all purposes of the Indenture.

               (c)  The designation of a Subsidiary as an Unrestricted
     Subsidiary or the designation of an Unrestricted Subsidiary as a Restricted
     Subsidiary in compliance with paragraph (b) hereof shall be made by the
     Board of Directors pursuant to a Board Resolution and shall be effective as
     of the date specified in such Board Resolution.

               SECTION 4.18. Reports. (a) The Company will file with the Trustee
     within 15 days after it files them with the Commission copies of the annual
     reports on Form 10-K and the information, documents, and other reports that
     the Company is required to file with the Commission pursuant to Section 13
     or 15(d) of the Exchange Act as well as quarterly reports ("SEC Reports").
     In the event the Company shall cease to be required to file SEC Reports
     pursuant to either of such sections of the Exchange Act, the Company will
     nevertheless continue to file such reports with the Commission (unless the
     Commission will not accept such a filing) and the Trustee. The Company will
     furnish copies of the SEC Reports to the Holders of Notes at the time the
     Company is required to file the same with the Trustee.

               (b)  From and after qualification of this Indenture under the
     Trust Indenture Act, the Company shall provide the information, documents,
     reports, summaries and certificates required by Section 314(a) of the Trust
     Indenture Act.

               (c)  The Company shall notify the Trustee when the Restricted
     Period terminates.

               SECTION 4.19. Statement of Compliance; Notice of Default or Event
     of Default. (a) The Company shall deliver to the Trustee on or before a
     date not more than 90 days after the end of each fiscal year of the Company
     ending after the date hereof, a statement regarding compliance with this
     Indenture.

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               (b)  The Company shall deliver to the Trustee, within 30 days
     after any executive officer of the Company becomes aware of the occurrence
     of any event which constitutes, or with the giving of notice or the lapse
     of time or both would constitute, a Default or Event of Default, a
     statement describing such Default or Event of Default, its status and what
     action the Company is taking or proposes to take with respect thereto.

               (c)  The Trustee may withhold from Holders notice of any
     continuing Default or Event of Default (other than relating to the payment
     of principal or interest) if the Trustee determines that withholding such
     notice is in the Holders' interest.

                                   ARTICLE V

      Amalgamation, Consolidation, Merger, Conveyance, Lease or Transfer
      ------------------------------------------------------------------

               SECTION 5.01. Merger, Consolidation or Sale of Assets. The
     Company will not, in any transaction or series of related transactions,
     amalgamate or consolidate with, or merge with or into, any other Person
     (other than a merger of a Restricted Subsidiary into the Company in which
     the Company is the surviving corporation), or sell, convey, assign,
     transfer, lease or otherwise dispose of all or substantially all of the
     Property and assets of the Company and its Restricted Subsidiaries taken as
     a whole to any other Person, unless:

               (a)  either (i) the Company shall be the surviving corporation or
     (ii) the corporation (if other than the Company) formed by such
     amalgamation or consolidation or into which the Company is merged, or the
     Person which acquires, by sale, assignment, conveyance, transfer, lease or
     disposition, all or substantially all of the Property and assets of the
     Company and the Restricted Subsidiaries taken as a whole (such corporation
     or Person, the "Surviving Entity"), shall be a corporation organized and
     validly existing under the laws of the United States of America, any
     political subdivision thereof, any state thereof or the District of
     Columbia, and shall expressly assume, by a supplemental indenture, the due
     and punctual payment of the principal of (and premium, if any) and interest
     on all the Notes and the performance of the Company's covenants and
     obligations under this Indenture;

               (b)  immediately after giving effect to such transaction or
     series of related transactions on a pro forma basis (including any
     Indebtedness Incurred in connection with or in respect of such transaction
     or series of related transactions), no Default shall have occurred and be
     continuing;

               (c)  immediately after giving effect to such transaction or
     series of related transactions on a pro forma basis (including any
     Indebtedness incurred in connection with or in respect of, and any
     Indebtedness to be repaid in connection with or as a result of, such
     transaction or series of related transactions), the Company (or the
     Surviving Entity, if the Company is not the surviving corporation) (i)
     shall have a Consolidated Net Worth equal to or greater than the
     Consolidated Net Worth of the Company immediately prior to such transaction
     and (ii) would be permitted to Incur at least $1 of additional Indebtedness
     pursuant to Section 4.09(a); provided that this clause (c)(ii) shall not
     apply to (X) a consolidation, merger or sale of all (but not less than all)
     of the assets of the Company if all Liens and Indebtedness of the company
     or the Surviving Entity, as the case may be, and its Restricted
     Subsidiaries outstanding immediately after such transaction would, if
     Incurred at such time, have been permitted to be Incurred (and all such
     Liens and Indebtedness, other than Liens and Indebtedness

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     of the Company and its Restricted Subsidiaries outstanding immediately
     prior to the transaction, shall be deemed to have been Incurred) for all
     purposes of the Indenture or (Y) a consolidation, merger, sale of all or
     substantially all of the assets of the Company if immediately after giving
     effect to such transaction or series of related transactions on a pro forma
     basis (including any Indebtedness incurred in connection with or in respect
     of, and any Indebtedness to be repaid in connection with or as a result of,
     such transaction or series of related transactions) the Company's (or the
     Surviving Entity's) leverage ration computed pursuant to Section 4.09(a)
     would be equal to or less than the leverage ratio of the Company
     immediately prior to such transaction;

               (d)  if, as a result of any such transaction, Property of the
     Company would become subject to a Lien prohibited by the provisions of this
     Indenture described under Section 4.12, the Company or the Surviving Entity
     to the Company shall have secured the Notes as required thereby; and

               (e)  the Company delivers to the Trustee an Officers' Certificate
     (attaching the arithmetic computations to demonstrate compliance with
     paragraph (c)) and Opinion of Counsel, in each case stating that such
     consolidation, merger or transfer and such supplemental indenture complies
     with this provision and that all conditions precedent provided for herein
     relating to such transaction have been complied with.

               SECTION 5.02. Successor Corporation Substituted. Upon any
     amalgamation or consolidation with, or merger by the Company with or into,
     any other corporation, or any sale, assignment, transfer, lease, conveyance
     or other disposition of all or substantially all of the Property and assets
     of the Company and its Restricted Subsidiaries taken as a whole in
     accordance with Section 5.01, the successor corporation formed by such
     amalgamation or consolidation or into which the Company is merged, or the
     Person to which such sale, conveyance, assignment, transfer, lease,
     conveyance or other disposition is made, shall succeed to, and be
     substituted for, and may exercise every right and power of, the Company
     under this Indenture with the same effect as if such successor Person has
     been named as the Company herein; and thereafter the predecessor
     corporation, except in the case of a lease referred to above, shall be
     relieved of all obligations and covenants under this Indenture and the
     Notes.

                                  ARTICLE VI

                             Defaults and Remedies
                             ---------------------

               SECTION 6.01. Events of Default. "Event of Default", wherever
     used herein with respect to the Notes, means any one of the following
     events (whatever the reason for such event, and whether it shall be
     voluntary or involuntary, or be effected by operation of law, pursuant to
     any judgment, decree or order of any court or any order, rule or regulation
     of any administrative or governmental body):

               (a)  default in the payment in full of interest (including
     Additional Interest, if any) on any Note when the same becomes due and
     payable, and the continuance of such default for a period of 30 days;

               (b)  default in the payment of the principal of (or premium, if
     any, on) any Note at its maturity, upon optional redemption, including a
     Change of Control Redemption Offer, required repurchase (including pursuant
     to a Change of Control Offer

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     or an Asset Sale Offer) or otherwise, or the failure to make an offer to
     purchase any Note as required under this Indenture;

               (c)  default in the performance, or breach, of any covenant or
     warranty of the Company in this Indenture (other than a covenant or
     warranty addressed in clauses (a) or (b) above) and continuance of such
     Default or breach for a period of 60 days after written notice thereof has
     been given to the Company by the Trustee or to the Company and the Trustee
     by Holders of at least 25% of the aggregate principal amount of the
     outstanding Notes specifying such Default and stating that such notice is a
     "Notice of Default" delivered in connection with this Indenture;

               (d)  (i) any principal payment in excess of $10,000,000 with
     respect to Indebtedness of the Company or any restricted Subsidiary is not
     paid when due within the applicable grace period, if any, or (ii)
     Indebtedness of the Company or any Restricted Subsidiary is accelerated by
     the Holders thereof and the principal amount of such accelerated
     Indebtedness exceeds $10,000,000;

               (e)  a final judgment or final judgments for the payment of money
     (other than to the extent covered by insurance as to which the insurance
     company has acknowledged coverage and other than to the extent covered by
     an indemnity given by an insurance company) is entered against the Company
     or any Restricted Subsidiary of the Company in an aggregate amount in
     excess of $10,000,000 by a court or courts of competent jurisdiction, which
     judgment is not discharged, waived, appealed, stayed, bonded or satisfied
     for a period of 60 consecutive days;

               (f)  the entry of a decree or order by a court having
     jurisdiction in the premises adjudging the Company or any Restricted
     Subsidiary bankrupt or insolvent, or approving as properly filed a petition
     seeking reorganization, arrangement, adjustment or composition of or in
     respect of the Company under the United States Bankruptcy Code or any other
     federal or state law or the law of any other jurisdiction relating to
     bankruptcy, insolvency, winding up, liquidation, reorganization or relief
     of debtors ("Bankruptcy Law"), or appointing a receiver, liquidator,
     assignee, trustee, sequestrator (or other similar official) of the Company
     or any Restricted Subsidiary or of any substantial part of its Property, or
     ordering the winding up or liquidation of its affairs, and the continuance
     of any such decree or order unstayed and in effect for a period of 60
     consecutive calendar days; provided that if the entry of such order or
     decree is appealed and dismissed on appeal or otherwise has ceased to be in
     effect then the Event of Default hereunder by reason of the entry of such
     order or decree shall be deemed to have been cured and the related
     acceleration shall be deemed rescinded; or

               (g)  the institution by the Company or any Restricted Subsidiary
     of proceedings to be adjudicated bankrupt or insolvent, or the consent by
     it to the institution of bankruptcy or insolvency proceedings against it,
     or the filing by it of a petition or answer or consent seeking
     reorganization or relief under any Bankruptcy Law or the consent by it to
     the filing of any such petition or to the appointment of a receiver,
     liquidator, assignee, trustee, sequestrator (or other similar official) of
     the Company or any Restricted Subsidiary or of any substantial part of its
     property, or the making by it of an assignment for the benefit of
     creditors, or the admission by it in writing of its inability to pay its
     debts generally as they become due.

               SECTION 6.02. Acceleration. (a) If any Event of Default (other
     than an Event of Default specified in Section 6.01(f) or Section 6.01(g))
     occurs and is continuing, then and in every such case, the Trustee by a
     notice in writing to the

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<PAGE>

     Company may, and at the direction of the Holders of not less than 25% of
     the out standing aggregate principal amount of the Notes by a notice in
     writing to the Company and the Trustee shall, declare the principal amount
     of, and any accrued and unpaid interest on, all Notes then outstanding to
     be immediately due and payable. Upon any such declaration, such principal
     amount of, and any accrued and unpaid interest on, all Notes then
     outstanding will become and be immediately due and payable.

               (b)  If an Event of Default specified in Section 6.01(f) or
     Section 6.01(g) occurs, the principal amount of, and any accrued and unpaid
     interest on, all Notes then outstanding shall ipso facto become and be
     immediately due and payable without any declaration or other act on the
     part of the Trustee or any Holder of Notes.

               (c)  Upon payment of the principal amount of, and any accrued and
     unpaid interest on, the Notes in accordance with clause (a) or (b) above,
     and any interest on any overdue principal, premium and interest (in each
     case to the extent that payment of such interest shall be legally
     enforceable), all of the Company's obligations in respect of the payment of
     the principal of, premium, if any, and interest on the Notes shall
     terminate.

               (d)  In the event of a declaration of acceleration because an
     Event of Default set forth in Section 6.01(d) has occurred and is
     continuing, such declaration of acceleration shall be automatically
     rescinded and annulled if the event of default triggering such Event of
     Default pursuant to Section 6.01(d) shall be remedied, or cured, or waived
     by the holders of the relevant Indebtedness, within 60 calendar days after
     such event of default; provided no judgment or decree for the payment of
     the money due on the Notes has been obtained by the Trustee as provided
     hereinafter in this Article VI.

               (e)  At any time after a declaration of acceleration with respect
     to the Notes has been made and before a judgment or decree for payment of
     the money due has been obtained by the Trustee as provided hereinafter in
     this Article VI, the Holders of not less than a majority in principal
     amount of the outstanding Notes, by written notice to the Company and the
     Trustee, may rescind and annul such declaration and its consequences if,

                    (i)  the Company has paid or deposited with the Trustee a
          sum sufficient to pay:

                         (A)  all overdue installments of interest on all Notes;

                         (B)  the principal of (and premium, if any, on) any
               Notes which have become due otherwise than by such declaration of
               acceleration and interest thereon at the rate or rates prescribed
               therefor in such Notes;

                         (C)  to the extent that payment of such interest is
               lawful, interest on the Defaulted Interest at the rate prescribed
               therefor in the Notes and this Indenture;

                         (D)  all moneys paid or advanced by the Trustee
               hereunder and the reasonable compensation, expenses,
               disbursements and advances of the Trustee, its agents and counsel
               and all other amounts due to the Trustee pursuant to Section
               7.07; and

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<PAGE>

                    (ii) all Events of Default with respect to the Notes, other
          than the nonpayment of the principal of Notes which have become due
          solely by such declaration of acceleration, have been cured or waived
          by the Holders as provided herein.

               (f)  No such rescission shall affect any subsequent Default or
     impair any right consequent thereon.

               SECTION 6.03. Other Remedies. (a) The Company covenants that if
     an Event of Default specified in Section 6.01(a) or Section 6.01(b) occurs
     the Company shall, upon demand of the Trustee, pay to the Trustee, for the
     benefit of the Holders, the whole amount then due and payable on the Notes
     for principal (and premium, if any) and interest and, to the extent that
     payment of such interest shall be legally enforceable, interest upon the
     overdue principal (and premium, if any) and upon Defaulted Interest, at the
     rate or rates prescribed therefor in such Notes; and, in addition thereto,
     such further amount as shall be sufficient to cover the costs and expenses
     of collection, including the reasonable compensation, expenses,
     disbursements and advances of the Trustee, its agents and counsel and all
     other amounts due to the Trustee pursuant to Section 7.07.

               (b)  If the Company fails to pay such amounts forthwith upon such
     demand, the Trustee, in its own name and as trustee of an express trust,
     may, and, subject to Section 6.05, at the direction of the Holders of not
     less than a majority of the outstanding aggregate principal amount of the
     Notes by a notice in writing to the Trustee, shall, institute a judicial
     proceeding for the collection of the sums so due and unpaid, and may
     prosecute such proceeding to judgment or final decree, and may enforce the
     same against the Company or any other obligor upon such Notes and collect
     the moneys adjudged or decreed to be payable in the manner provided by law
     out of the Property and assets of the Company or any other obligor upon
     such Notes, wherever situated.

               (c)  If an Event of Default with respect to the Notes occurs and
     is continuing, the Trustee may in its discretion proceed to protect and
     enforce its rights and the rights of the Holders by such appropriate
     judicial proceedings as the Trustee shall deem most effectual to protect
     and enforce any such rights, whether for the specific enforcement of any
     covenant or agreement in this Indenture or in aid of the exercise of any
     power granted herein, or to enforce any other proper remedy.

               SECTION 6.04. Waiver of Past Defaults. The Holders of not less
     than a majority in principal amount of the outstanding Notes may, on behalf
     of the Holders of all the Notes, waive any past Default and its
     consequences under this Article VI, except a Default (a) in the payment of
     the principal (or premium, if any) or interest on, any Note, or (b) in
     respect of a covenant or provision hereof which under Section 9.02(a)
     cannot be modified or amended without the consent of the Holder of each
     outstanding Note affected.

               SECTION 6.05. Control by Majority. The Holders of not less than a
     majority in principal amount of the outstanding Notes shall have the right
     to direct the time, method and place of conducting any proceeding for
     exercising any remedy available to the Trustee or exercising any trust or
     power conferred on the Trustee; provided that

               (a)  such direction shall not be in conflict with any rule of law
          or with this Indenture or unduly prejudicial to the rights of other
          Holders (it being understood

                                      73
<PAGE>

          that, subject to Section 7.01, the Trustee shall have no duty to
          ascertain whether or not the actions or forebearances specified in or
          pursuant to such direction are unduly prejudicial to such Holders) and
          would not subject the Trustee to personal liability, and

               (b)  the Trustee may take any other action deemed proper by the
          Trustee which is not inconsistent with such direction.

               SECTION 6.06. Limitation on Suits. No Holder of Notes shall have
     any right to institute any proceeding, judicial or otherwise, with respect
     to this Indenture, or for the appointment of a receiver or trustee, or for
     any other remedy hereunder, unless

               (a)  such Holder has previously given written notice to the
          Trustee of a continuing Event of Default with respect to the Notes;

               (b)  the Holders of not less than 25% in principal amount of the
          outstanding Notes shall have made written request to the Trustee to
          institute proceedings in respect of such Event of Default in its own
          name as Trustee hereunder;

               (c)  such Holder or Holders have offered and, if requested,
          provided to the Trustee security or indemnity satisfactory to the
          Trustee in its reasonable discretion against the costs, expenses and
          liabilities to be incurred in compliance with such request;

               (d)  the Trustee for 30 calendar days after its receipt of such
          notice, request and offer of indemnity has failed to institute any
          such proceeding; and

               (e)  no direction inconsistent with such written request has been
          given to the Trustee during such 30-day period by the Holders of not
          less than a majority in principal amount of the outstanding Notes;

     in any event, it being understood and intended that no one or more Holders
     of Notes shall have any right in any manner whatever by virtue of, or by
     availing of, any provision of this Indenture to affect, disturb or
     prejudice the rights of any other Holders of Notes, or to obtain or to seek
     to obtain priority or preference over any other of such Holders or to
     enforce any right under this Indenture, except in the manner herein
     provided and for the equal and ratable benefit of all Holders of Notes.

               SECTION 6.07. Rights of Holders To Receive Payment.
     Notwithstanding any other provision of this Indenture, the right of any
     Holder to receive payment of principal of (premium, if any) and interest on
     the Notes held by such Holder, on or after the respective due dates
     expressed in the Notes or the Redemption Dates or purchase dates provided
     for therein, or to bring suit for the enforcement of any such payment on or
     after such respective dates, shall be absolute and unconditional and shall
     not be impaired or affected without the consent of such Holder.

               SECTION 6.08. Trustee May File Proofs of Claim. In case of the
     pendency of any receivership, insolvency, liquidation, bankruptcy,
     reorganization, arrangement, adjustment, composition or other judicial
     proceedings, or any voluntary or involuntary case under Bankruptcy Law, as
     now or hereafter constituted, relative to the Company or any other obligor
     upon the Notes or the Property and assets of the Company or of such other
     obligor or their creditors, the Trustee (irrespective of whether the

                                      74
<PAGE>

     principal of such Notes shall then be due and payable as therein expressed
     or by declaration or otherwise and irrespective of whether the Trustee
     shall have made any demand on the Company for the payment of overdue
     principal or interest) shall be entitled and empowered, by intervention in
     such proceeding or otherwise, (a) to file and prove a claim for the whole
     amount of principal (and premium, if any) and interest owing and unpaid in
     respect of the Notes, to file such other papers or documents and to take
     such other actions, including participating as a member or otherwise in any
     official committee of creditors appointed in the matter, as may be
     necessary or advisable in order to have the claims of the Trustee
     (including any claim for the reasonable compensation, expenses,
     disbursements and advances of the Trustee, its agents and counsel and all
     other amounts due to the Trustee pursuant to Section 7.07) and of the
     Holders allowed in such judicial proceeding, and (b) to collect and receive
     any moneys or other Property payable or deliverable on any such claims and
     to distribute the same; and any receiver, assignee, trustee, custodian,
     liquidator, sequestrator (or other similar official) in any such proceeding
     is hereby authorized by each Holder to make such payments to the Trustee,
     and in the event that the Trustee shall consent to the making of such
     payments directly to the Holders, to pay to the Trustee any amount due it
     for the reasonable compensation, expenses, disbursements and advances of
     the Trustee, its agents and counsel, and any other amounts due the Trustee
     under Section 7.07. Nothing contained herein shall be deemed to authorize
     the Trustee to authorize or consent to or accept or adopt on behalf of any
     Holder any plan of reorganization, arrangement, adjustment or composition
     affecting the Notes or the rights of any Holder thereof, or to authorize
     the Trustee to vote in respect of the claim of any Holder in any such
     proceeding.

               SECTION 6.09. Priorities. (a) Any money collected by the Trustee
     pursuant to this Article VI shall be applied in the following order, at the
     date or dates fixed by the Trustee and, in case of the distribution of such
     money on account of principal (or premium, if any) or interest, upon
     presentation of the Notes and the notation thereon of the payment if only
     partially paid and upon surrender thereof if fully paid:

               (i)   FIRST: To the payment of all amounts due the Trustee under
          Section 7.07;

               (ii)  SECOND: To the payment of the amounts then due and unpaid
          for principal (and premium, if any) and interest on the Notes,
          ratably, without preference or priority of any kind, according to the
          amounts due and payable on such Notes for the principal (and premium,
          if any) and interest, respectively; and

               (iii) THIRD: To the Company.

               (b)  The Trustee may fix a record date and payment date for any
     payment to Holders pursuant to this Section 6.09. At least 15 calendar days
     before such record date, the Trustee at the expense of the Company shall
     send to each Holder by first class mail, postage prepaid, a notice prepared
     by the Company that states such record date, the payment date and amount to
     be paid.

               SECTION 6.10. Undertaking for Costs. All parties to this
     Indenture agree, and each Holder of any Note by such Holder's acceptance
     thereof shall be deemed to have agreed, that any court may in its
     discretion require, in any suit for the enforcement of any right or remedy
     under this Indenture, or in any suit against the Trustee for any action
     taken, suffered or omitted by it as Trustee, the filing by any party
     litigant in such suit of an undertaking to pay the costs of such suit and
     that such court

                                      75
<PAGE>

     may in its discretion assess reasonable costs, including reasonable
     attorneys' fees, against any party litigant in such suit, having due regard
     to the merits and good faith of the claims or defenses made by such party
     litigant; but the provisions of this Section 6.10 shall not apply to any
     suit instituted by the Trustee, to any suit instituted by any Holder, or
     group of Holders, holding in the aggregate more than 10% in principal
     amount of the outstanding Notes, or to any suit instituted by any Holder
     for the enforcement of the payment of the principal (or premium, if any) or
     interest on any Note on or after its Stated Maturity.

               SECTION 6.11. Waiver of Stay or Extension Laws. The Company (to
     the extent it may lawfully do so) shall not at any time insist upon, or
     plead, or in any manner whatsoever claim or take the benefit or advantage
     of, any stay or extension law wherever enacted, now or at any time
     hereafter in force, which may affect the covenants or the performance of
     this Indenture; and the Company (to the extent that it may lawfully do so)
     hereby expressly waives all benefit or advantage of any such law, and shall
     not hinder, delay or impede the execution of any power herein granted to
     the Trustee, but shall suffer and permit the execution of every such power
     as though no such law had been enacted.

               SECTION 6.12. Trustee May Enforce Claims Without Possession of
     the Notes. All rights of action and claims under this Indenture or the
     Notes may be prosecuted and enforced by the Trustee without the possession
     of any of the Notes or the production thereof in any proceeding relating
     thereto, and any such proceeding instituted by the Trustee shall be brought
     in its own name, as trustee of an express trust, and any recovery of
     judgment shall, after provision for the payment of the reasonable
     compensation, expenses, disbursements and advances of the Trustee, its
     agents and counsel, be for the ratable benefit of the Holders of the Notes.

               SECTION 6.13. Restoration of Rights and Remedies. If the Trustee
     or any Holder of Notes has instituted any proceeding to enforce any right
     or remedy under this Indenture and such proceeding has been discontinued or
     abandoned for any reason, or has been determined adversely to the Trustee
     or to such Holder, then and in every such case the Company, the Trustee and
     the Holders shall, subject to any determination in such proceeding, be
     restored severally and respectively to their former positions hereunder,
     and thereafter all rights and remedies of the Trustee and the Holders shall
     continue as though no such proceeding had been instituted.

               SECTION 6.14. Rights and Remedies Cumulative. Except as otherwise
     provided in Section 2.09, no right or remedy herein conferred upon or
     reserved to the Trustee or to the Holders is intended to be exclusive of
     any other right or remedy, and every right and remedy shall, to the extent
     permitted by law, be cumulative and in addition to every other right and
     remedy given hereunder or now or hereafter existing at law or in equity or
     otherwise. The assertion or employment of any right or remedy hereunder, or
     otherwise, shall not prevent the concurrent assertion or employment of any
     other appropriate right or remedy.

               SECTION 6.15. Delay or Omission Not Waiver. No delay or omission
     of the Trustee or of any Holder of any Note to exercise any right or remedy
     accruing upon any Event of Default shall impair any such right or remedy or
     constitute a waiver of any such Event of Default or an acquiescence
     therein. Every right and remedy given by this Article VI or by law to the
     Trustee or to the Holders may be exercised from time to time, and as often
     as may be deemed expedient, by the Trustee or by the Holders, as the case
     may be.

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                                  ARTICLE VII

                                    Trustee
                                    -------

          SECTION 7.01.  Duties of Trustee.  (a)  If an Event of Default has
occurred and is continuing, the Trustee shall exercise the rights and powers
vested in it by this Indenture and shall use the same degree of care in their
exercise as a prudent person would exercise or use under the circumstances in
the conduct of such person's own affairs.

          (b)  Except during the continuance of an Event of Default of which a
Trust Officer has actual knowledge: (i) the Trustee undertakes to perform such
duties and only such duties as are specifically set forth in this Indenture and
no implied covenants or obligations shall be read into this Indenture against
the Trustee; and (ii) in the absence of bad faith on its part, the Trustee may
conclusively rely, as to the truth of the statements and the correctness of the
opinions expressed therein, upon certificates or opinions furnished to the
Trustee and conforming to the requirements of this Indenture; provided that in
the case of any such certificates or opinions that by any provision of this
Indenture are specifically required to be furnished to the Trustee, the Trustee
shall examine such certificates and opinions to determine whether or not they
conform to the requirements of this Indenture.

          (c)  The Trustee may not be relieved from liability for its own
negligent action, its own negligent failure to act or its own willful
misconduct; provided that: (i) this paragraph (c) shall not limit the effect of
paragraph (b) of this Section 7.01; (ii) the Trustee shall not be liable for any
error of judgment made in good faith by a Trust Officer unless it is proved that
the Trustee was negligent in ascertaining the pertinent facts; and (iii) the
Trustee shall not be liable with respect to any action it takes or omits to take
in good faith in accordance with a direction received by it pursuant to Section
6.05.

          (d)  Money held in trust by the Trustee need not be segregated from
other funds except to the extent required by law.

          (e)  No provision of this Indenture shall require the Trustee to
expend or risk its own funds or otherwise incur any financial liability in the
performance of any of its duties hereunder, or in the exercise of any of its
rights or powers, if it shall have reasonable grounds for believing that
repayment of such funds or adequate indemnity against such risk of liability is
not reasonably assured to it.

          (f)  Every provision of this Indenture relating to the conduct or
affecting the liability of or affording protection to the Trustee shall be
subject to the provisions of this Article VII and to the provisions of the Trust
Indenture Act.

          SECTION 7.02.  Rights of Trustee.  (a)  The Trustee may rely on any
document believed by it to be genuine and to have been signed or presented by
the proper Person.

          (b)  Before the Trustee acts or refrains from acting, it may require
an Officers' Certificate or an Opinion of Counsel.  The Trustee shall not be
liable for any action it takes or omits to take in good faith in reliance on any
Officers' Certificate or Opinion of Counsel.

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<PAGE>

          (c)  The Trustee shall not be liable for any action it takes or omits
to take in good faith which it believes to be authorized or within its rights or
powers; provided that the Trustee's conduct does not constitute willful
misconduct or gross negligence.

          (d)  Before the Trustee acts or refrains from acting, it may consult
with counsel and the written advice of such counsel or any Opinion of Counsel
shall be full and complete authorization and protection in respect of any action
taken, suffered or omitted by it hereunder in good faith and in reliance
thereon.

          (e)  The Trustee shall not be bound to make any investigation into the
facts or matters stated in any resolution, certificate, statement, instrument,
opinion, report, notice, request, direction, consent, order, bond, debenture or
other paper or document, but the Trustee, in its discretion, may make such
further inquiry or investigation into such facts or matters as it may see fit,
and, if the Trustee shall determine to make such further inquiry or
investigation, it shall be entitled to examine the books, records and premises
of the Company, personally or by agent or attorney.

          (f)  The Trustee shall not be liable for any action it takes or omits
to take in good faith in accordance with the direction of the Holders of not
less than a majority of the aggregate outstanding principal amount of Notes
relating to the time, method and place of conducting any proceeding for any
remedy available to the Trustee, or exercising any trust or power conferred upon
the Trustee, under this Indenture.

          (g)  The Trustee shall be under no obligation to exercise any of the
rights or powers vested in it by this Indenture at the request or direction of
any of the Holders pursuant to this Indenture, unless such Holders shall have
offered to the Trustee security reasonable to it or indemnity against the costs,
expenses and liabilities which might be incurred by it in compliance with such
request or direction.

          (h)  The Trustee may execute any of the trusts or powers hereunder or
perform any duties hereunder either directly or by or through agents or
attorneys and the Trustee shall not be responsible for any willful misconduct or
negligence on the part of any agent or attorney appointed with due care by it
hereunder.

          (i)  The Trustee shall not be charged with knowledge of any Default or
Event of Default unless it shall have received written notice thereof from the
Company or the Holder of a Note or unless a Trust Officer shall have actual
knowledge thereof.

          (j)  The Trustee shall not be required to give any bond or surety in
respect of the performance of its powers and duties hereunder.

          (k)  The permissive rights to the Trustee to do things enumerated in
this Indenture shall not be construed as a duty.

          SECTION 7.03.  Individual Rights of Trustee.  The Trustee, any Paying
Agent or Note Registrar, in its individual or any other capacity, may become the
owner or pledgee of Notes and may otherwise deal with the Company, its
Restricted Subsidiaries or its Affiliates with the same rights it would have if
it were not Trustee, Paying Agent or Note Registrar hereunder, as the case may
be; provided that the Trustee must in any event comply with Sections 7.10 and
7.11.

          SECTION 7.04.  Trustee's Disclaimer.  The Trustee shall not be
responsible for and makes no representation as to the validity or adequacy of
this

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<PAGE>

Indenture or the Notes, it shall not be accountable for the Company's use of the
proceeds from the Notes, and it shall not be responsible (a) for any statement
of the Company in this Indenture, including the recitals contained herein, or in
any document issued in connection with the sale of the Notes or in the Notes
other than the Trustee's certificate of authentication or (b) for compliance by
the Company with the Registration Agreement.

          SECTION 7.05.  Notice of Defaults.  Within 90 calendar days after the
occurrence of any Default hereunder known to a Trust Officer with respect to the
Notes, the Trustee shall transmit by mail to all Holders, as their names and
addresses appear in the Note Register, notice of such Default hereunder known to
the Trustee, unless such Default shall have been cured or waived; provided that,
except in the case of a Default in the payment of the principal (or premium, if
any) or interest on any Note, the Trustee shall be protected in withholding such
notice if and so long as the board of directors, the executive committee or a
trust committee of directors and/or Trust Officers of the Trustee in good faith
determine that the withholding of such notice is in the interest of the Holders.

          SECTION 7.06.  Preservation of Information; Reports by Trustee to
Holders.  (a)  The Company shall furnish or cause to be furnished to the
Trustee:

          (i)   semiannually, not less than ten calendar days prior to each
     January 15 and July 15, a list, in such form as the Trustee may reasonably
     require, of the names and addresses of the Holders as of the Regular Record
     Date immediately preceding such January 15 and July 15, and

          (ii)  at such other times as the Trustee may request in writing,
     within 30 calendar days after the receipt by the Company of any such
     request, a list of similar form and content as of a date not more than 15
     calendar days prior to the time such list is furnished;

provided that if and so long as the Trustee shall be the Note Registrar for the
Notes, no such list need be furnished with respect to the Notes.

          (b)  The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 7.06(a) and the names and
addresses of Holders received by the Trustee in its capacity as Note Registrar,
if so acting.  The Trustee may destroy any list furnished to it as provided in
Section 7.06(a) upon receipt of a new list so furnished.

          (c)  Holders may communicate as provided in Section 312(b) of the
Trust Indenture Act with other Holders with respect to their rights under this
Indenture or under the Notes.

          (d)  Each Holder of Notes, by receiving and holding the same, agrees
with the Company and the Trustee that neither the Company nor the Trustee shall
be held accountable by reason of the disclosure of any such information as to
the names and addresses of the Holders in accordance with this Section 7.06,
regardless of the source from which such information was derived, and that the
Trustee shall not be held accountable by reason of mailing any material pursuant
to a request made under this Section 7.06.

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<PAGE>

          (e)  Within 60 calendar days after April 15 of each year commencing
with the year 2000, the Trustee shall transmit by mail to all Holders of Notes,
a brief report dated as of such April 15 if and to the extent required under
Section 313(a) of the Trust Indenture Act.

          (f)  The Trustee shall comply with Sections 313(b) and 313(c) of the
Trust Indenture Act.

          (g)  A copy of each report described in Section 7.06(e) or referred to
in Section 7.06(f) shall, at the time of its transmission to Holders, be filed
by the Trustee with each securities exchange, if any, upon which the Notes are
then listed, with the Commission and also with the Company.  The Company shall
promptly notify the Trustee of any securities exchange upon which the Notes are
listed.

          SECTION 7.07.  Compensation and Indemnity.  (a)  The Company shall pay
to the Trustee from time to time reasonable compensation for its services.  The
Company shall reimburse the Trustee upon request for all reasonable out-of-
pocket expenses incurred or made by it, including costs of collection, in
addition to the compensation for its services.  Such expenses shall include the
reasonable compensation and expenses, disbursements and advances of the
Trustee's agents and counsel.  The Trustee's compensation shall not be limited
by any law on compensation of a trustee of an express trust.

          (b)  The Company shall indemnify the Trustee for, and hold it harmless
against, any and all loss, liability or expense (including reasonable attorneys'
fees) arising out of or incurred by it in connection with the acceptance or
administration of the trust created by this Indenture and the performance of its
duties hereunder, except as set forth in Section 7.07(c).  The Trustee shall
notify the Company promptly of any claim for which it may seek indemnity.
Failure by the Trustee to so notify the Company shall not relieve the Company of
its obligations hereunder.  The Company shall defend any such claim and the
Trustee shall cooperate in the defense of such claim.  The Trustee may have
separate counsel and the Company shall pay the reasonable fees and expenses of
such counsel.  The Company need not pay for any settlement made without its
consent, which consent shall not be unreasonably withheld.

          (c)  The Company need not reimburse any expense or indemnify against
any loss, liability or expense incurred by the Trustee through the Trustee's own
willful misconduct, negligence or bad faith.

          (d)  To secure the Company's payment obligations in this Section 7.07,
the Trustee shall have a Lien prior to the Notes on all money or property held
or collected by the Trustee other than money or property held in trust to pay
the principal, premium (if any), and interest on, particular Notes.

          (e)  The Company's payment obligations pursuant to this Section 7.07
shall survive the resignation or removal of the Trustee and discharge of this
Indenture. Subject to any other rights available to the Trustee under applicable
Bankruptcy Law, when the Trustee incurs expenses after the occurrence of a
Default specified in Section 6.01(f) or Section 6.01(g) hereof, the expenses are
intended to constitute expenses of administration under bankruptcy law.

          SECTION 7.08.  Replacement of Trustee.  (a)  No resignation or removal
of the Trustee and no appointment of a successor Trustee pursuant to this
Article VII

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<PAGE>

shall become effective until the acceptance of appointment by the successor
Trustee under this Section 7.08.

          (b)    The Trustee may resign at any time by giving written notice
thereof to the Company.  If an instrument of acceptance by a successor Trustee
shall not have been delivered to the Trustee within 30 calendar days after the
giving of such notice of resignation, the resigning Trustee may petition any
court of competent jurisdiction for the appointment of a successor Trustee.

          (c)    The Trustee may be removed at any time by Act of the Holders of
not less than a majority in principal amount of the outstanding Notes, delivered
to the Trustee and to the Company.

          (d)    If at any time:

          (i)    the Trustee shall fail to comply with Section 310(b) of the
     Trust Indenture Act after written request therefor by the Company or by any
     Holder who has been a bona fide Holder of a Note for at least six months,
     unless the Trustee's duty to resign is stayed in accordance with the
     provisions of Section 310(b) of the Trust Indenture Act; or

          (ii)   the Trustee shall cease to be eligible under Section 7.10 and
     shall fail to resign after written request therefor by the Company or by
     any such Holder; or

          (iii)  the Trustee shall become incapable of acting or a decree or
     order for relief by a court having jurisdiction in the premises shall have
     been entered in respect of the Trustee in an involuntary case under
     Bankruptcy Law, as now or hereafter constituted; or a decree or order by a
     court having jurisdiction in the premises shall have been entered for the
     appointment of a receiver, custodian, liquidator, assignee, trustee,
     sequestrator (or other similar official) of the Trustee or of its Property
     and assets or affairs, or any public officer shall take charge or control
     of the Trustee or of its Property and assets or affairs for the purpose of
     rehabilitation, conservation, winding up or liquidation; or

          (iv)   the Trustee shall commence a voluntary case under Bankruptcy
     Law, as now or hereafter constituted, or shall consent to the appointment
     of or taking possession by a receiver, custodian, liquidator, assignee,
     trustee, sequestrator (or other similar official) of the Trustee or its
     Property and assets or affairs, or shall make an assignment for the benefit
     of creditors, or shall admit in writing its inability to pay its debts
     generally as they become due, or shall take corporate action in furtherance
     of any such action;

then, in any such case, (A) the Company by a Board Resolution may remove the
Trustee with respect to the Notes, or (B) subject to Section 6.10, any Holder
who has been a bona fide Holder of a Note for at least six months may, on behalf
of such Holder and all others similarly situated, petition any court of
competent jurisdiction for the removal of the Trustee and the appointment of a
successor Trustee for the Notes.

          (e)    If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, the
Company, by or pursuant to a Board Resolution, shall promptly appoint a
successor Trustee.  If, within one year after such resignation, removal or
incapacity, or the occurrence of such vacancy, a successor Trustee shall be
appointed by the Holders of not less than a

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<PAGE>

majority in principal amount of the outstanding Notes by written notice to the
Company and the retiring Trustee, the successor Trustee so appointed shall,
forthwith upon its acceptance of such appointment in accordance with this
Section 7.08, become the successor Trustee and to that extent replace any
successor Trustee appointed by the Company. If no successor Trustee shall have
been so appointed by the Company or the Holders and shall have accepted
appointment in the manner hereinafter provided, any Holder that has been a bona
fide Holder of a Note for at least six months may, subject to Section 6.10, on
behalf of himself and all others similarly situated, petition any court of
competent jurisdiction for the appointment of a successor Trustee.

          (f)  The Company shall give notice of each resignation and each
removal of the Trustee and each appointment of a successor Trustee by mailing
written notice of such resignation, removal and appointment by first class mail,
postage prepaid, to the Holders as their names and addresses appear in the Note
Register.  Each notice shall include the name of the successor Trustee with
respect to the Notes and the address of its Corporate Trust Office.

          (g)  In the event of an appointment hereunder of a successor Trustee,
each such successor Trustee so appointed shall execute, acknowledge and deliver
to the Company and to the retiring Trustee an instrument accepting such
appointment, and thereupon the resignation or removal of the retiring Trustee
shall become effective and such successor Trustee, without any further act, deed
or conveyance, shall become vested with all the rights, powers, trusts and
duties of the retiring Trustee but, on request of the Company or the successor
Trustee, such retiring Trustee shall, upon payment of its charges, execute and
deliver an instrument transferring to such successor Trustee all the rights,
powers and trusts of the retiring Trustee, and shall duly assign, transfer and
deliver to such successor Trustee all Property and money held by such former
Trustee hereunder, subject to its Lien, if any, provided for in Section 7.07.

          (h)  Upon request of any such successor Trustee, the Company shall
execute any and all instruments for more fully and certainly vesting in and
confirming to such successor Trustee all such rights, powers and trusts referred
to in Section 7.08(g).

          (i)  No successor Trustee shall accept its appointment unless at the
time of such acceptance such successor Trustee shall be qualified and eligible
under this Article VII and under the Trust Indenture Act.

          SECTION 7.09.  Successor Trustee by Merger.  Any corporation into
which the Trustee may be merged or converted or with which it may be
consolidated, or any corporation resulting from any merger, conversion or
consolidation to which the Trustee shall be a party, or any corporation
succeeding to all or substantially all of the corporate trust business of the
Trustee, shall be the successor of the Trustee hereunder; provided that such
corporation shall be otherwise qualified and eligible under this Article VII and
under the Trust Indenture Act, without the execution or filing of any paper or
any further act on the part of any of the parties hereto.  In case any Notes
shall have been authenticated, but not delivered, by the Trustee then in office,
any successor by merger, conversion or consolidation to such authenticating
Trustee may adopt such authentication and deliver the Notes so authenticated
with the same effect as if such successor Trustee had itself authenticated such
Notes.  In the event that any Notes shall not have been authenticated by such
predecessor Trustee, any such successor Trustee may authenticate and deliver
such Notes, in either its own name or that of its predecessor Trustee, with the
full force and effect which this Indenture provides for the certificate of
authentication of the Trustee.

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<PAGE>

           SECTION 7.10.  Eligibility; Disqualification.  (a)  There shall at
all times be a Trustee hereunder which shall be

          (i)   a corporation organized and doing business under the laws of the
     United States of America, any State or Territory thereof or the District of
     Columbia, authorized under such laws to exercise corporate trust powers,
     and subject to supervision or examination by Federal, State, Territorial or
     District of Columbia authority,

          (ii)  or a corporation or other Person organized and doing business
     under the laws of a foreign government that is permitted to act as Trustee
     pursuant to a rule, regulation or order of the Commission, authorized under
     such laws to exercise corporate trust powers, and subject to supervision or
     examination by authority of such foreign government or a political
     subdivision thereof substantially equivalent to supervision or examination
     applicable to United States institutional trustees,

in either case having a combined capital and surplus of at least $25,000,000.

          (b)  If such Person publishes reports of condition at least annually,
pursuant to law or to the requirements of the aforesaid supervising or examining
authority, then for the purposes of this Section 7.10, the combined capital and
surplus of such corporation shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published.
Neither the Company nor any Affiliate of the Company nor any Restricted
Subsidiary shall serve as Trustee hereunder.  If at any time the Trustee shall
cease to be eligible to serve as Trustee hereunder pursuant to the provisions of
this Section 7.10, it shall resign immediately in the manner and with the effect
specified in this Article VII.

          (c)  If the Trustee has or shall acquire any "conflicting interest"
within the meaning of Section 310(b) of the Trust Indenture Act, the Trustee and
the Company shall in all respects comply with the provisions of Section 310(b)
of the Trust Indenture Act.  Nothing herein shall prevent the Trustee from
filing with the Commission the application referred to in the penultimate
paragraph of Section 310(b) of the Trust Indenture Act.

          SECTION 7.11.  Preferential Collection of Claims Against Company. The
Trustee shall comply with Section 311(a) of the Trust Indenture Act, excluding
any creditor relationship listed in Section 311(b) of the Trust Indenture Act.
A Trustee who has resigned or been removed shall be subject to Section 311(a) of
the Trust Indenture Act to the extent indicated therein.

                                 ARTICLE VIII

                                  Defeasance
                                  ----------

          SECTION 8.01.  Company's Option To Effect Legal Defeasance or Covenant
Defeasance.  The Company may elect, at its option, at any time, to have Section
8.02 or Section 8.03 applied to the outstanding Notes (in whole and not in part)
upon compliance with the conditions set forth below in this Article VIII.  Such
election shall be evidenced by a Board Resolution delivered to the Trustee.

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<PAGE>

          SECTION 8.02.  Legal Defeasance and Discharge.  (a)  Upon the
Company's exercise of its option to have this Section 8.02 applied to the
outstanding Notes (in whole and not in part), the Company shall be deemed to
have been discharged from its obligations with respect to such Notes as provided
in this Section 8.02 on and after the date the conditions set forth in Section
8.04 are satisfied (hereinafter called "Defeasance").  For this purpose, such
Defeasance means that the Company shall be deemed to have paid and discharged
the entire Indebtedness represented by such Notes and to have satisfied all its
other obligations under such Notes and this Indenture insofar as such Notes are
concerned (and the Trustee, at the expense of the Company, shall execute proper
instruments acknowledging the same), subject to the following which shall
survive until otherwise terminated or discharged hereunder:

          (i)    the rights of Holders of such Notes to receive, solely from the
     trust fund described in Section 8.04 and as more fully set forth in such
     Section 8.04, payments in respect of the principal of (premium, if any) and
     interest on such Notes (but not the Change of Control Purchase Price or the
     Offer Purchase Price) when payments are due, and any rights of Holders of
     such Notes with respect to such amounts,

          (ii)   the Company's obligations with respect to such Notes under
     Section 2.08, 2.09, 2.12, 4.02 and 4.03,

          (iii)  the rights, powers, trusts, obligations and immunities of the
     Trustee under this Indenture,

          (iv)   Article III hereof, and

          (v)    this Article VIII.

          (b)    Subject to compliance with this Article VIII, the Company may
exercise its option to have this Section 8.02 applied to the outstanding Notes
(in whole and not in part) notwithstanding the prior exercise of its option to
have Section 8.03 applied to such Notes.

          SECTION 8.03.  Covenant Defeasance.  Upon the Company's exercise of
its option to have this Section 8.03 applied to the outstanding Notes (in whole
and not in part), (a) the Company shall be released from its obligations under
Section 5.01(d) and (e) hereof, Sections 4.05 through 4.18 (except to the extent
required by the Trust Indenture Act), inclusive, and any covenant added to this
Indenture subsequent to the Issue Date pursuant to Section 9.01, and (b) the
occurrence of any event specified in Section 6.01(c), with respect to any of
Section 5.01(d) and (e), Sections 4.05 through 4.18 (except to the extent
required by the Trust Indenture Act), inclusive, and any covenant added to this
Indenture subsequent to the Issue Date pursuant to Section 9.01, shall be deemed
not to be or result in an Event of Default, in each case with respect to such
Notes as provided in this Section 8.03 on and after the date the conditions set
forth in Section 8.04 are satisfied (hereinafter called "Covenant Defeasance").
For this purpose, such Covenant Defeasance means that, with respect to such
Notes, the Company may omit to comply with and shall have no liability in
respect of any term, condition or limitation set forth in any such specified
Section (to the extent so specified in the case of Section 6.01(c)), whether
directly or indirectly by reason of any reference elsewhere herein to any such
Section or by reason of any reference in any such Section to any other provision
herein or in any other document, but the remainder of this Indenture and such
Notes shall be unaffected thereby.

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<PAGE>

          SECTION 8.04.  Conditions to Defeasance or Covenant Defeasance. The
following shall be the conditions to the application of Section 8.02 or Section
8.03 to the outstanding Notes:

          (a)  The Company shall irrevocably have deposited or caused to be
deposited with the Trustee as trust funds in trust for the purpose of making the
following payments on the outstanding Notes, specifically pledged as security
for such Notes, and dedicated solely to the benefit of the Holders of such
Notes, (i) United States dollars in an amount, or (ii) U.S. Government
Obligations which through the scheduled payment of principal and interest
thereon in accordance with their terms will provide, not later than one day
before the due date of any payment in respect of the outstanding Notes, United
States dollars in an amount, or (iii) a combination thereof, in each case
sufficient, in the opinion of an internationally recognized firm of independent
public accountants expressed in a written certification thereof delivered to the
Trustee, to pay and discharge, and which shall be applied by the Trustee to pay
and discharge, the principal of and interest on such Notes on the respective
Stated Maturities or Redemption Dates thereof, in accordance with the terms of
this Indenture and such Notes.

          (b)  In the event of an election to have Section 8.02 apply to the
outstanding Notes, the Company shall have delivered to the Trustee an Opinion of
Counsel reasonably acceptable to the Trustee stating that (i)(A) the Company has
received from, or there has been published by, the Internal Revenue Service a
ruling or (B) since the date of this Indenture, there has been a change in the
applicable United States federal income tax law, in either case (A) or (B) to
the effect that, and based thereon such Opinion of Counsel shall confirm that,
the Holders of such Notes will not recognize gain or loss for United States
federal income tax purposes as a result of the deposit, Defeasance and discharge
to be effected with respect to such Notes and will be subject to United States
federal income tax in the same manner and at the same times as would have been
the case if the Defeasance had not occurred and (ii) the Company's deposit will
not result in the trust created thereby or the Trustee being subject to
regulation under the Investment Company Act of 1940, as amended.

          (c)  In the event of an election to have Section 8.03 apply to the
outstanding Notes, the Company shall have delivered to the Trustee an Opinion of
Counsel reasonably acceptable to the Trustee stating that (i) the Holders of
such Notes will not recognize gain or loss for United States federal income tax
purposes as a result of the deposit and Covenant Defeasance to be effected with
respect to such Notes and will be subject to United States federal income tax in
the same manner and at the same times as would have been the case if the
Covenant Defeasance had not occurred and (ii) the Company's deposit will not
result in the trust created thereby or the Trustee being subject to regulation
under the Investment Company Act of 1940, as amended.

          (d)  No Default or Event of Default with respect to the outstanding
Notes shall have occurred and be continuing at the time of such deposit after
giving effect thereto or at any time on or prior to the 91st calendar day after
the date of such deposit (it being understood that this condition shall not be
deemed satisfied until after such 91st calendar day).

          (e)  Such Defeasance or Covenant Defeasance shall not cause the
Trustee to have a conflicting interest within the meaning of the Trust Indenture
Act (assuming for the purpose of this clause (e) that all Notes are in default
within the meaning of the Trust Indenture Act).

                                      85
<PAGE>

          (f)  Such Defeasance or Covenant Defeasance shall not result in a
breach or violation of, or constitute a default under, any other agreement or
instrument to which the Company is a party or by which it is bound.

          (g)  If the Notes are to be redeemed prior to Stated Maturity, notice
of such redemption shall have been duly given pursuant to this Indenture or
provision therefor satisfactory to the Trustee shall have been made.

          (h)  The Company shall have delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel, each stating that all conditions
precedent with respect to such Defeasance or Covenant Defeasance have been
complied with.

          SECTION 8.05.  Deposited United States Dollars and U.S. Government
Obligations To Be Held in Trust; Miscellaneous Provisions.  (a)  All United
States dollars and U.S. Government Obligations (including the proceeds thereof)
deposited or deemed to be deposited with the Trustee pursuant to Section 8.04 in
respect of the outstanding Notes shall be held in trust and applied by the
Trustee, in accordance with the provisions of such Notes and this Indenture, to
the payment, either directly or through any Paying Agent as the Trustee may
determine, to the Holders of such Notes, of all sums due and to become due
thereon in respect of principal and any premium and interest, but money so held
in trust need not be segregated from other funds except to the extent required
by law.  The Company shall pay and indemnify the Trustee against any tax, fee or
other charge imposed on or assessed against the U.S. Government Obligations
deposited pursuant to Section 8.04 or principal of and interest received in
respect thereof other than any such tax, fee or other charge which by law is for
the account of the Holders of outstanding Notes.

          (b)  Anything in this Article VIII to the contrary notwithstanding,
the Trustee shall deliver or pay to the Company from time to time upon Company
Order any United States dollars or U.S. Government Obligations held by it as
provided in Section 8.04 which, in the opinion of an internationally recognized
firm of independent public accountants expressed in a written certification
thereof delivered to the Trustee, are in excess of the amount that would then be
required to be deposited to effect the Defeasance or Covenant Defeasance, as the
case may be, with respect to the outstanding Notes.

          (c)  The Trustee and the Paying Agent shall pay to the Company upon
written request any money held by them for the payment of principal (premium, if
any), or interest that remains unclaimed for two years; provided that the
Trustee or such Paying Agent before being required to make any payment may cause
to be published at the expense of the Company once in a newspaper of general
circulation in the City of New York or mail to each Holder entitled to such
money at such Holder's address (as set forth in the Note Register) notice that
such money remains unclaimed and that after a date specified therein (which
shall be at least 30 calendar days from the date of such publication or mailing)
any unclaimed balance of such money then remaining will be repaid to the
Company.  After payment to the Company, Holders entitled to such money must look
only to the Company for payment as general creditors, and all responsibility and
liability of the Trustee and such Paying Agent with respect to such money shall
cease.

          SECTION 8.06.  Reinstatement.  If the Trustee or Paying Agent is
unable to apply any money in accordance with this Article VIII with respect to
any Notes by reason of any order or judgment of any court or governmental
authority enjoining,

                                      86
<PAGE>

restraining or otherwise prohibiting such application, then the obligations
under this Indenture and such Notes from which the Company has been discharged
or released pursuant to Sections 8.02 or 8.03 shall be revived and reinstated as
though no deposit had occurred pursuant to this Article VIII with respect to
such Notes, until such time as the Trustee or Paying Agent is permitted to apply
all money held in trust pursuant to Section 8.05 with respect to such Notes in
accordance with this Article VIII; provided that if the Company makes any
payment of principal of or any premium or interest on any such Note following
such reinstatement of its obligations, the Company shall be subrogated to the
rights (if any) of the Holders of such Notes to receive such payment from the
money so held in trust.

                                  ARTICLE IX

                                  Amendments
                                  ----------

          SECTION 9.01.  Without Consent of Holders.  The Company and the
Trustee may, at any time, and from time to time, without notice to or consent of
any Holder of Notes, enter into one or more indentures supplemental hereto, in
form satisfactory to the Trustee, for any of the following purposes:

          (a)  to evidence the succession of another Person to the Company in
     accordance with the terms of this Indenture and the assumption by such
     successor of the covenants of the Company herein and in the Notes;

          (b)  to add to the covenants of the Company, for the benefit of the
     Holders of all of the Notes, or to surrender any right or power herein
     conferred upon the Company;

          (c)  to add any additional Events of Default;

          (d)  to evidence and provide for the acceptance of appointment
     hereunder of a successor Trustee;

          (e)  to secure the Notes;

          (f)  to cure any ambiguity herein, or to correct or supplement any
     provision hereof which may be inconsistent with any other provision hereof
     or to add any other provisions with respect to matters or questions arising
     under this Indenture; provided that such actions shall not adversely affect
     the interests of the Holders of Notes in any material respect; or

          (g)  to comply with the requirements of the Commission or any other
     regulatory authority in order to effect or maintain the qualification of
     this Indenture under the Trust Indenture Act.

          SECTION 9.02.  With Consent of Holders.  (a)  With the consent of the
Holders of not less than a majority in principal amount of the outstanding
Notes, by Act of said Holders delivered to the Company and the Trustee, the
Company and the Trustee may enter into one or more indentures supplemental
hereto for the purpose of adding any provisions to or changing in any manner or
eliminating any of the provisions of this Indenture or of modifying in any
manner the rights of the Holders; provided that no such

                                      87
<PAGE>

supplemental indenture shall, without the consent of the Holder of each
outstanding Note,

          (i)    change the Stated Maturity of the principal of, or the due date
     of any installment of interest on, any Note, or alter the redemption
     provisions thereof, or reduce the principal amount thereof (or premium, if
     any), or the interest thereon, that would be due and payable upon Maturity
     thereof, or change the place of payment where, or the coin or currency in
     which, any Note or any premium or interest thereon is payable;

          (ii)   reduce the percentage in principal amount of the outstanding
     Notes;

          (iii)  subordinate in right of payment, or otherwise subordinate, the
     Notes to any other Indebtedness;

          (iv)   impair the right to institute suit for the enforcement of any
     payment with respect to the Notes;

          (v)    make any change that would result in the Company being required
     to make any deduction or withholding from any payment made under or with
     respect to the Notes; or

          (vi)   modify any of the provisions of this Section 9.02, except to
     increase any percentage set forth herein or to provide that certain other
     provisions of this Indenture cannot be modified or waived without the
     consent of the Holder of each outstanding Note affected thereby.

          (b)    It shall not be necessary for any Act of Holders under this
Section 9.02 to approve the particular form of any proposed supplemental
indenture, but it shall be sufficient if such Act shall approve the substance
thereof.

          SECTION 9.03.  Effect of Supplemental Indentures.  Upon the execution
of any supplemental indenture under this Article IX, this Indenture shall be
modified in accordance therewith, and such supplemental indenture shall form a
part of this Indenture for all purposes; and every Holder of Notes theretofore
or thereafter authenticated and delivered hereunder shall be bound thereby.

          SECTION 9.04.  Compliance with Trust Indenture Act.  Every amendment
or supplement to this Indenture or the Notes shall comply with the Trust
Indenture Act as then in effect.

          SECTION 9.05.  Revocation and Effect of Consents and Waivers.  (a)  A
consent to an amendment, supplement or a waiver by a Holder of a Note shall bind
the Holder and every subsequent Holder of such Note or portion of such Note that
evidences the same debt as the consenting Holder's Note, even if notation of the
consent or waiver is not made on such Note; provided that any such Holder or
subsequent Holder may revoke the consent or waiver as to such Holder's Note or
portion of such Note if the Trustee receives the notice of revocation at least
one Business Day prior to the date the amendment, supplement or waiver becomes
effective.  After an amendment, supplement or waiver becomes effective pursuant
to this Article IX, it shall bind every Holder.

          (b)  The Company may, but shall not be obligated to, fix a record date
for the purpose of determining the Holders entitled to give their consent or
take any other

                                      88
<PAGE>

action described above or required or permitted to be taken pursuant to this
Indenture. If a record date is fixed, then notwithstanding the immediately
preceding paragraph, those Persons who were Holders at such record date (or
their duly designated proxies), and only those Persons, shall be entitled to
give such consent or to revoke any consent previously given or to take any such
action, whether or not such Persons continue to be Holders after such record
date. No such consent shall be valid or effective for more than 120 calendar
days after such record date.

          SECTION 9.06.  Notation on or Exchange of Notes.  If a supplemental
indenture changes the terms of a Note, the Trustee may require the Holder
thereof to deliver such Note to the Trustee.  The Trustee may place an
appropriate notation on such Note regarding the changed terms and return it to
the Holder.  Alternatively, if the Company or the Trustee so determines, the
Company in exchange for such Note shall issue and the Trustee shall authenticate
a new Note that reflects the changed terms. Failure to make the appropriate
notation or to issue a new Note shall not affect the validity of such
supplement.

          SECTION 9.07. Trustee To Execute Supplemental Indentures.  The Trustee
shall execute any supplemental indenture authorized pursuant to this Article IX
if such supplemental indenture does not adversely affect the rights, duties,
liabilities or immunities of the Trustee.  If it does, the Trustee may, but
shall not be required to, execute such supplemental indenture.  In executing any
supplemental indenture, the Trustee shall receive and shall be (subject to
Section 7.01) fully protected in relying upon an Officers' Certificate and an
Opinion of Counsel, which shall not be at the expense of the Trustee, stating
that the execution of such supplemental indenture is authorized or permitted by
this Indenture.

                                   ARTICLE X

                                 Miscellaneous
                                 -------------

          SECTION 10.01.  Trust Indenture Act Controls.  If and to the extent
that any provision of this Indenture limits, qualifies or conflicts with the
duties imposed by, or with another provision (an "incorporated provision")
included in this Indenture by operation of Sections 310 to 318, inclusive, of
the Trust Indenture Act, such imposed duties or incorporated provision shall
control.  If any provisions of this Indenture modifies or excludes any provision
of the TIA that may be so modified or excluded, the Indenture as so modified or
with such exclusion shall apply.

          SECTION 10.02.  Notices.  (a) Any notice or communication shall be in
writing and delivered in person or mailed by first-class mail, postage prepaid,
addressed as follows.  If to the Company: 200 N. LaSalle, Chicago, Illinois
60601, Attention: Chief Financial Officer; with a copy to Jones, Day, Reavis &
Pogue, 77 West Wacker, Chicago, Illinois 60601, Attention: Elizabeth C.
Kitslaar, if to the Trustee:  Harris Trust and Savings Bank, 311 West Monroe
Street, 12th Floor, Chicago, Illinois 60606, Attention: Corporate Trust
Administration.

          (b)  The Company or the Trustee, by notice to the other, may designate
additional or different addresses for subsequent notices or communications.  Any
notice or communication mailed to a Holder shall be sent to the Holder by first-
class mail, postage prepaid, at the Holder's address as it appears in the Note
Register and shall be duly given if so sent within the time prescribed.  Failure
to mail a notice or

                                      89
<PAGE>

communication to a Holder or any defect in it shall not affect its sufficiency
with respect to other Holders. If a notice or communication is mailed to the
Company, the Trustee or a Holder in the manner provided above, it is duly given,
whether or not the addressee receives it. In case by reason of the suspension of
regular mail service or by reason of any other cause it shall be impracticable
to give notice by mail to Holders, then such notification as shall be made with
the approval of the Trustee shall constitute a sufficient notification for every
purpose hereunder.

          SECTION 10.03.  Certificate and Opinion as to Conditions Precedent.
Upon any request or application by the Company to the Trustee to take or refrain
from taking any action under this Indenture, the Company shall furnish to the
Trustee:  (a) an Officers' Certificate stating that, in the opinion of the
signers, all conditions precedent, if any, provided for in this Indenture
relating to the proposed action have been complied with; and (b) an Opinion of
Counsel stating that, in the opinion of such counsel, all such conditions
precedent have been complied with.

          SECTION 10.04.  Statements Required in Certificate or Opinion.  Each
certificate or opinion with respect to compliance with a covenant or condition
provided for in this Indenture (other than pursuant to Section 4.19) shall
include:  (a) a statement that the individual making such certificate or opinion
has read such covenant or condition; (b) a brief statement as to the nature and
scope of the examination or investigation upon which the statements or opinions
contained in such certificate or opinion are based; (c) a statement that, in the
opinion of such individual, such person has made such examination or
investigation as is necessary to enable such person to express an informed
opinion as to whether or not such covenant or condition has been complied with;
and (d) a statement as to whether or not, in the opinion of such individual,
such covenant or condition has been complied with; provided that, with respect
to matters of fact, an Opinion of Counsel may rely on an Officers' Certificate
or certificates of public officials.

          SECTION 10.05.  Rules by Trustee, Paying Agent and Note Registrar. The
Trustee may make reasonable rules for action by or a meeting of Holders, and any
Note Registrar and Paying Agent may make reasonable rules for their functions;
provided that no such rule shall conflict with the terms of this Indenture or
the Trust Indenture Act.

          SECTION 10.06.  Payments on Business Days.  If a payment hereunder is
scheduled to be made on a date that is not a Business Day, payment shall be made
on the next succeeding day that is a Business Day, and no interest shall accrue
with respect to that payment during the intervening  period.  If a regular
record date is a date that is not a Business Day, such record date shall not be
affected.

          SECTION 10.07.  Governing Law; Jurisdiction.  THIS INDENTURE AND THE
NOTES SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE
STATE OF NEW YORK WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF
LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD
BE REQUIRED THEREBY.  EACH OF THE PARTIES HERETO AGREE TO SUBMIT TO THE NON-
EXCLUSIVE JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK IN ANY ACTION OR
PROCEEDING ARISING OUT OF OR RELATING TO THIS INDENTURE.

                                      90
<PAGE>

          SECTION 10.08.  No Recourse Against Others.  No controlling Person,
director, officer, employee, incorporator or stockholder of the Company, as
such, shall have any liability for any covenant, agreement or other obligations
of the Company under the Notes or this Indenture or for any claim based on, in
respect of, or by reason of, such obligations or their creation, solely by
reason of its past, present or future status as a controlling Person, director,
officer, employee, incorporator or stockholder of the Company.  By accepting a
Note, each Holder waives and releases all such liability (but only such
liability) as part of the consideration for issuance of such Note to such
Holder.

          SECTION 10.09. Successors.  All agreements of the Company in this
Indenture and the Notes shall bind its successors and assigns whether so
expressed or not.  All agreements of the Trustee in this Indenture shall bind
its successors and assigns whether so expressed or not.

          SECTION 10.10.  Counterparts.  This Indenture may be executed in any
number of counterparts and by the parties thereto in separate counterparts, each
of which when so executed shall be deemed to be an original and all of which
taken together shall constitute one and the same agreement.

          SECTION 10.11.  Table of Contents; Headings.  The table of contents,
cross-reference table and headings of the Articles and Sections of this
Indenture have been inserted for convenience of reference only, are not intended
to be considered a part hereof and shall not modify or restrict any of the terms
or provisions hereof.

          SECTION 10.12.  Severability.  In case any provision in this Indenture
or in the Notes shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.

          SECTION 10.13.  Further Instruments and Acts.  Upon request of the
Trustee, the Company will execute and deliver such further instruments and do
such further acts as may be reasonably necessary or proper to carry out more
effectively the purposes of this Indenture.

                    [Remainder of Page Intentionally Blank]

                                      91
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Indenture to
be duly executed all as of the day and year first above written.

                                       FOCAL COMMUNICATIONS CORPORATION

                                          /s/ Robert C. Taylor, Jr.
                                       By ________________________________
                                          Name: Robert C. Taylor, Jr.
                                          Title: Director, President and
                                                 Chief Executive Officer

                                       HARRIS TRUST AND SAVINGS BANK,
                                       as Trustee,

                                          /s/ J. Bartolini
                                       By ________________________________
                                          Name: J. Bartolini
                                          Title: Vice President
<PAGE>

                                                                         ANNEX A
                                                Form of Regulation S Certificate

                           REGULATION S CERTIFICATE

              (For transfers pursuant to (S) 2.08(g)(i) and (iii)
                               of the Indenture)

Harris Trust and Savings Bank
311 West Monroe Street
Chicago, Illinois 60606

Attention: Indenture Trust Division

     Re:  11.875 Senior Notes due 2010
          of Focal Communications Corporation (the "Notes")
          ------------------------------------------------

          Reference is made to the Indenture, dated as of January 12, 2000 (the
"Indenture"), between Focal Communications Corporation (the "Company") and
Harris Trust and Savings Bank, as Trustee.  Terms used herein and defined in the
Indenture or in Regulation S or Rule 144 under the U.S. Securities Act of 1933,
as amended (the "Securities Act"), are used herein as so defined.

          This certificate relates to $________________principal amount of
Notes, which are evidenced by the following certificates (the "Specified
Notes"):

          CUSIP No(s)._______________________________________

          CERTIFICATE No(s)._________________________________

The person in whose name this certificate is executed below (the "Undersigned")
hereby certifies that either (i) it is the sole beneficial owner of the
Specified Notes or (ii) it is acting on behalf of all the beneficial owners of
the Specified Notes and is duly authorized by them to do so.  Such beneficial
owner or owners are referred to herein collectively as the "Owner".  If the
Specified Notes are represented by a Global Note, they are held through the
Depositary or an Agent Member in the name of the Undersigned, as or on behalf of
the Owner.  If the Specified Notes are not represented by a Global Note, they
are registered in the name of the Undersigned, as or on behalf of the Owner.

          The Owner has requested that the Specified Notes be transferred to a
person (the "Transferee") who will take delivery in the form of a Regulation S
Note.  In connection with such transfer, the Owner hereby certifies that, unless
such transfer is being effected pursuant to an effective registration statement
under the Securities Act, it is being effected in accordance with Rule 904 or
Rule 144 under the Securities Act and with all applicable securities laws of the
states of the United States and other jurisdictions.  Accordingly, the Owner
hereby further certifies as follows:

          (1)  Rule 904 Transfers.  If the transfer is being effected in
     accordance with Rule 904:

                                       1
<PAGE>

               (A)  the Owner is not a distributor of the Notes, an affiliate of
          the Company or any such distributor or a person acting on behalf of
          any of the foregoing;

               (B)  the offer of the Specified Notes was not made to a person in
          the United States;

               (C)  either:

                         (i)   at the time the buy order was originated, the
               Transferee was outside the United States or the Owner and any
               person acting on its behalf reasonably believed that the
               Transferee was outside the United States, or

                         (ii)  the transaction is being executed in, on or
               through the facilities of the Eurobond market, as regulated by
               the Association of International Bond Dealers, or another
               designated offshore securities market and neither the Owner nor
               any person acting on its behalf knows that the transaction has
               been prearranged with a buyer in the United States;

               (D)  no directed selling efforts have been made in the United
          States by or on behalf of the Owner or any affiliate thereof;

               (E)  if the Owner is a dealer in securities or has received a
          selling concession, fee or other remuneration in respect of the
          Specified Notes, and the transfer is to occur during the Restricted
          Period, then the requirements of Rule 904(c)(1) have been satisfied;
          and

               (F)  the transaction is not part of a plan or scheme to evade the
          registration requirements of the Securities Act.

          (2)  Rule 144 Transfers.  If the transfer is being effected pursuant
     to Rule 144:

               (A)  the transfer is occurring after a holding period of at least
          one year (computed in accordance with paragraph (d) of Rule 144) has
          elapsed since the Specified Notes were last acquired from the Company
          or from an affiliate of the Company, whichever is later, and is being
          effected in accordance with the applicable amount, manner of sale and
          notice requirements of Rule 144; or

               (B)  the transfer is occurring after a holding period of at least
          two years has elapsed since the Specified Notes were last acquired
          from the Company or from an affiliate of the Company, whichever is
          later, and the Owner is not, and during the preceding three months has
          not been, an affiliate of the Company.

          The Owner also hereby certifies that, if the transfer is occurring
during the period of 40 consecutive days beginning on and including the later of
(A) the day on which the Notes were first offered to persons other than
distributors (as defined in Regulation S of the Securities Act) in reliance on
Regulation S and (B) the original issuance date of the Notes (the "Restricted
Period"), the Transferee shall hold the

                                       2
<PAGE>

Specified Notes in the form of a Global Note held only in or through accounts
maintained at the Depositary by Euroclear or Cedel (or by Agent Members acting
for the account thereof) until the expiration of the Restricted Period.

          This certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the Initial Purchasers.

Dated:

                         ________________________________________
                         (Print the name of the Undersigned, as such term is
                         defined in the second paragraph of this certificate.)

                         By _____________________________________
                            Name:
                            Title:

                         (If the Undersigned is a corporation, partnership or
                         fiduciary, the title of the person signing on behalf of
                         the Undersigned must be stated.)

                                       3
<PAGE>

                                                                         ANNEX B
                                            Form of Restricted Notes Certificate

                         RESTRICTED NOTES CERTIFICATE

                  (For transfers pursuant to (S) 2.08(g)(ii)
                          and (iii) of the Indenture)

Harris Trust and Savings Bank
311 West Monroe Street
Chicago, Illinois 60606

Attention: Indenture Trust Division

     Re:  11.875% Senior Notes due 2010
          of Focal Communications Corporation (the "Notes")
          -------------------------------------------------

          Reference is made to the Indenture, dated as of January 12, 2000 (the
"Indenture"), between Focal Communications Corporation (the "Company") and
Harris Trust and Savings Bank, as Trustee.  Terms used herein and defined in the
Indenture or in Regulation S or Rule 144 under the U.S. Securities Act of 1933,
as amended (the "Securities Act"), are used herein as so defined.

          This certificate relates to $_______________ principal amount of
Notes, which are evidenced by the following certificates (the "Specified
Notes"):

          CUSIP No(s). ______________________________

          CERTIFICATE No(s). ________________________

The person in whose name this certificate is executed below (the "Undersigned")
hereby certifies that either (i) it is the sole beneficial owner of the
Specified Notes or (ii) it is acting on behalf of all the beneficial owners of
the Specified Notes and is duly authorized by them to do so.  Such beneficial
owner or owners are referred to herein collectively as the "Owner".  If the
Specified Notes are represented by a Global Note, they are held through the
Depositary or an Agent Member in the name of the Undersigned, as or on behalf of
the Owner.  If the Specified Notes are not represented by a Global Note, they
are registered in the name of the Undersigned, as or on behalf of the Owner.

          The Owner has requested that the Specified Notes be transferred to a
person (the "Transferee") who will take delivery in the form of a Restricted
Note.  In connection with such transfer, the Owner hereby certifies that, unless
such transfer is being effected pursuant to an effective registration statement
under the Securities Act, it is being effected in accordance with Rule 144A,
Rule 144 or to an Institutional Accredited Investor under Rule 501(a)(1), (2),
(3) or (7) under the Securities Act and in compliance with all applicable
securities laws of the states of the United States and other jurisdictions.
Accordingly, the Owner hereby further certifies as follows:

          (1)  Rule 144A Transfers.  If the transfer is being effected in
     accordance with Rule 144A:

                                       1
<PAGE>

               (A)  the Specified Notes are being transferred to a person that
          the Owner and any person acting on its behalf reasonably believe is a
          "qualified institutional buyer" within the meaning of Rule 144A,
          acquiring for its own account or for the account of a qualified
          institutional buyer; and

               (B)  the Owner and any person acting on its behalf have taken
          reasonable steps to ensure that the Transferee is aware that the Owner
          may be relying on Rule 144A in connection with the transfer; and

          (2)  Rule 144 Transfers.  If the transfer is being effected pursuant
     to Rule 144:

               (A)  the transfer is occurring after a holding period of at least
          one year (computed in accordance with paragraph (d) of Rule 144) has
          elapsed since the Specified Notes were last acquired from the Company
          or from an affiliate of the Company, whichever is later, and is being
          effected in accordance with the applicable amount, manner of sale and
          notice requirements of Rule 144; or

               (B)  the transfer is occurring after a holding period of at least
          two years has elapsed since the Specified Notes were last acquired
          from the Company or from an affiliate of the Company, whichever is
          later, and the Owner is not, and during the preceding three months has
          not been, an affiliate of the Company.

          (3)  Institutional Accredited Investor Transfers.  If the transfer is
     being effected to an Institutional Accredited Investor as defined under
     Rule 501(a)(1), (2), (3) or (7), the Specified Notes are being transferred
     to such an Institutional Accredited Investor as therein so defined who is
     purchasing for investment purposes and not for distribution.

          This certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the Initial Purchasers.

Dated:                   _____________________________________
                         (Print the name of the Undersigned, as such term is
                         defined in the second paragraph of this certificate.)

                         By: _________________________________
                             Name:
                             Title:

                         (If the Undersigned is a corporation, partnership or
                         fiduciary, the title of the person signing on behalf of
                         the Undersigned must be stated.)

                                       2
<PAGE>

                                                                         ANNEX C
                                          Form of Unrestricted Notes Certificate

                        UNRESTRICTED NOTES CERTIFICATE

              (For removal of Securities Act Legends pursuant to
                      (S) 2.08(h)(iii) of the Indenture)

Harris Trust and Savings Bank
311 West Monroe Street
Chicago, Illinois 60606

Attention: Indenture Trust Division

     Re:  11.875 % Senior Notes due 2010
          of Focal Communications Corporation ("the Notes")
          -------------------------------------------------

          Reference is made to the Indenture, dated as of January 12, 2000 (the
"Indenture"), between Focal Communications Corporation (the "Company") and
Harris Trust and Savings Bank, as Trustee.  Terms used herein and defined in the
Indenture or in Regulation S or Rule 144 under the U.S. Securities Act of 1933,
as amended (the "Securities Act"), are used herein as so defined.

          This certificate relates to $______________ principal amount of Notes,
which are evidenced by the following certificates (the "Specified Notes"):

          CUSIP No(s).____________________________

          CERTIFICATE No(s).______________________

The person in whose name this certificate is executed below (the "Undersigned")
hereby certifies that either (i) it is the sole beneficial owner of the
Specified Notes or (ii) it is acting on behalf of all the beneficial owners of
the Specified Notes and is duly authorized by them to do so.  Such beneficial
owner or owners are referred to herein collectively as the "Owner".  If the
Specified Notes are represented by a Global Note, they are held through the
Depositary or an Agent Member in the name of the Undersigned, as or on behalf of
the Owner.  If the Specified Notes are not represented by a Global Note, they
are registered in the name of the Undersigned, as or on behalf of the Owner.

          The Owner has requested that the Specified Notes be exchanged for
Notes bearing no Securities Act Legend pursuant to Section 2.08(h)(iii) of the
Indenture.  In connection with such exchange, the Owner hereby certifies that
the exchange is occurring after a holding period of at least two years (computed
in accordance with paragraph (d) of Rule 144) has elapsed since the Specified
Notes were last acquired from the Company or from an affiliate of the Company,
whichever is later, and the Owner is not, and during the preceding three months
has not been, an affiliate of the Company.  The Owner also acknowledges that any
future transfers of the Specified Notes must comply with all applicable
securities laws of the states of the United States and other jurisdictions.

                                       1
<PAGE>

          This certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the Initial Purchasers.

Dated:
                         ___________________________________________
                         (Print the name of the Undersigned, as such term is
                         defined in the second paragraph of this certificate.)

                         By: _______________________________________
                             Name:
                             Title:

                         (If the Undersigned is a corporation, partnership or
                         fiduciary, the title of the person signing on behalf of
                         the Undersigned must be stated).

                                       2
<PAGE>

                                                                         ANNEX D

                      FORM OF CLEARING SYSTEM CERTIFICATE

     Re:  Focal Communications Corporation
          11.875% Senior Notes due 2010
          (the "Notes")

          Reference is hereby made to the Indenture dated as of January 12, 2000
(the "Indenture"), between Focal Communications Corporation (the "Company") and
Harris Trust and Savings Bank (the "Trustee").  Capitalized terms not defined in
this Certificate shall have the meanings given to them in the Indenture.

          This is to certify that, as of the date hereof, with respect to
$___________ principal amount of Notes, except as set forth below, we have
received in writing by tested telex or by electronic transmission, from our
Agent Members entitled to a portion of such principal amount, certifications
with respect to such portion substantially to the effect set forth in the
Indenture.

          We further certify (i) that we are not making available herewith for
exchange any portion of the Temporary Regulation S Global Note excepted in such
certifications and (ii) that as of the date hereof we have not received any
notification from any of our Agent Members to the effect that the statements
made by such Agent Members with respect to any portion of the part submitted
herewith for exchange are no longer true and cannot be relied upon as the date
hereof.

          We understand that this certification is required in connection with
certain securities laws of the United States.  In connection therewith, if
administrative or legal proceedings are commenced or threatened in connection
with which this

                                       1
<PAGE>

certification is or would be relevant, we irrevocably authorize you to produce
this certification to any interested party in such proceedings.

Dated: ___________,

                                       Yours faithfully,

                                       MORGAN GUARANTY TRUST
                                       COMPANY OF NEW YORK, Brussels office,
                                       as operator of the Euroclear System

                                       By: ___________________________________
                                           Name:
                                           Title:

                                                          or

                                       CEDEL S.A.

                                       By: ___________________________________
                                           Name:
                                           Title:

                                       2
<PAGE>

                                                                         ANNEX E

                  FORM OF CERTIFICATE OF BENEFICIAL OWNERSHIP

     Re:  Focal Communications Corporation
          11.875% Senior Notes due 2010
          (the "Notes")

          Reference is hereby made to the Indenture dated as of January 12, 2000
(the "Indenture"), between Focal Communications Corporation (the "Company") and
Harris Trust and Savings Bank (the "Trustee").  Capitalized terms not defined in
this Certificate shall have the meanings given to them in the Indenture.

          This is to certify that, as of the date hereof, the above-captioned
Notes held by you for our account are beneficially owned by (a) non-U.S.
person(s) or (b) U.S. person(s) who purchased the Notes in transactions which
did not require registration under the Securities Act of 1933, as amended (the
"Act").  As used in this paragraph the term "U.S. person" has the meaning given
to it by Regulation S under the Act.

          We undertake to advise you promptly by tested telex on or prior to the
date on which you intend to submit your certification relating to the Notes held
by you for our account in accordance with your operating procedures if any
applicable statement herein is not correct on such date, and in the absence of
any such notification it may be assumed that this certification applies as of
such date.

          We understand that this certification is required in connection with
certain securities laws of the United States.  In connection therewith, if
administrative or legal proceedings are commenced or threatened in connection
with which this certification is or would be relevant, we irrevocably authorize
you to produce this certification to any interested party in such proceedings.

Dated:                 ,

By: __________________________________
    As, or as agent for, the
    beneficial owner(s) of the
    Notes to which this
    certificate relates.

                                       1<PAGE>
                                                                    Exhibit 4.29

              [FORM OF 11-7/8% SENIOR NOTE DUE JANUARY 15, 2010]

CUSIP NO. 344155AD8

No. 1                                                               $274,870,000

          Focal Communications Corporation, a Delaware corporation (herein
called the "Company", which term includes any successor Person under the
            -------
indenture referred to on the reverse of this Note) for value received, hereby
promises to pay to Cede & Co., or registered assigns, the principal amount of
two hundred seventy-five million dollars ($275,000,000) (which principal amount
may from time to time be increased or decreased to such other principal amounts
(which shall not exceed $275,000,000 at any time) by adjustments made to the
Schedule annexed hereto by the Trustee hereinafter referred to in accordance
with the indenture referred to on the reverse of this Note) on January 15, 2010.

          Interest Payment Dates:    January 15 and July 15, commencing on July
                                     15, 2000.

          Regular Record Dates:      January 1 and July 1.

          UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE COMPANY
                                                          ---
OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY
CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME
AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE
TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER
HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

          TRANSFERS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS IN WHOLE,
BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR SUCH
SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL NOTE SHALL BE
LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE
INDENTURE REFERRED TO ON THE REVERSE HEREOF.

          THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "SECURITIES ACT").  THE HOLDER BY PURCHASING THIS NOTE AGREES FOR
THE BENEFIT OF THE COMPANY AND THE INITIAL PURCHASERS OF THIS NOTE THAT THIS
NOTE MAY NOT BE RESOLD, PLEDGED OR OTHERWISE TRANSFERRED (X) PRIOR TO THE SECOND
ANNIVERSARY (OR SUCH EARLIER DATE PROVIDED FOR IN RULE 144(K) UNDER THE
SECURITIES ACT OR ANY SUCCESSOR PROVISION THERETO) OF THE ISSUANCE HEREOF (OR A
PREDECESSOR NOTE HERETO) OR (Y) IF LATER, BY ANY HOLDER THAT WAS AN AFFILIATE OF
THE COMPANY AT ANY TIME DURING THE THREE MONTHS PRECEDING THE DATE OF SUCH
TRANSFER, IN EITHER CASE OTHER THAN (1) TO THE COMPANY, (2) SO LONG AS THIS NOTE
IS ELIGIBLE FOR RESALE PURSUANT TO RULE 144A UNDER THE SECURITIES
<PAGE>

ACT ("RULE 144A"), TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A
QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF RULE 144A PURCHASING FOR ITS
OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE
IS GIVEN THAT THE RESALE, PLEDGE OR OTHER TRANSFER IS BEING MADE IN RELIANCE ON
RULE 144A (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE CERTIFICATE
OF TRANSFER ON THE REVERSE OF THIS NOTE), (3) IN AN OFFSHORE TRANSACTION IN
ACCORDANCE WITH REGULATION S UNDER THE SECURITIES ACT (AS INDICATED BY THE BOX
CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS
NOTE), AND, IF SUCH TRANSFER IS BEING EFFECTED BY CERTAIN TRANSFERORS SPECIFIED
IN THE INDENTURE PRIOR TO THE EXPIRATION OF THE "40-DAY RESTRICTED PERIOD"
(WITHIN THE MEANING OF RULE 903(c)(3) OF REGULATION S UNDER THE SECURITIES ACT),
A CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE TRUSTEE IS DELIVERED
BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE, (4) TO AN INSTITUTION THAT IS
AN "ACCREDITED INVESTOR" AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) UNDER THE
SECURITIES ACT (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE
CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS NOTE) THAT IS ACQUIRING THIS NOTE
FOR INVESTMENT PURPOSES AND NOT FOR DISTRIBUTION IN VIOLATION OF THE SECURITIES
ACT OR ANY OTHER APPLICABLE SECURITIES LAWS, AND A CERTIFICATE IN THE FORM
ATTACHED TO THIS NOTE IS DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE
TRUSTEE (PROVIDED THAT CERTAIN HOLDERS SPECIFIED IN THE INDENTURE MAY NOT
TRANSFER THIS NOTE PURSUANT TO THIS CLAUSE (4) PRIOR TO THE EXPIRATION OF THE
"40-DAY RESTRICTED PERIOD" (WITHIN THE MEANING OF RULE 903(c)(3) OF REGULATION S
UNDER THE SECURITIES ACT)), (5) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER
THE SECURITIES ACT PROVIDED BY RULE 144 (IF APPLICABLE) UNDER THE SECURITIES
ACT, OR (6) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES
ACT, IN EACH CASE IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE
OF THE UNITED STATES. AN INSTITUTIONAL ACCREDITED INVESTOR HOLDING THIS NOTE
AGREES IT WILL FURNISH TO THE COMPANY AND THE TRUSTEE SUCH CERTIFICATES AND
OTHER INFORMATION AS THE COMPANY MAY REASONABLY REQUIRE TO CONFIRM THAT ANY
TRANSFER BY IT OF THIS NOTE COMPLIES WITH THE FOREGOING RESTRICTIONS. THE HOLDER
HEREOF, BY PURCHASING THIS NOTE, REPRESENTS AND AGREES FOR THE BENEFIT OF THE
COMPANY THAT IT IS (1) A QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF
RULE 144(A) OR (2) AN INSTITUTION THAT IS AN "ACCREDITED INVESTOR" AS DEFINED IN
RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT AND THAT IT IS HOLDING
THIS NOTE FOR INVESTMENT PURPOSES AND NOT FOR DISTRIBUTION OR (3) A NON-U.S.
PERSON OUTSIDE THE UNITED STATES WITHIN THE MEANING OF (OR AN ACCOUNT SATISFYING
THE REQUIREMENTS OF PARAGRAPH (k)(2) OF RULE 902 UNDER) REGULATION S UNDER THE
SECURITIES ACT.

          Reference is hereby made to the further provisions of this Note set
forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

                                       2
<PAGE>

          Unless the certificate of authentication hereon has been executed by
the Trustee referred to on the reverse hereof by manual signature, this Note
shall not be entitled to any benefit under the indenture referred to on the
reverse of this Note or be valid or obligatory for any purpose.

          IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.

Dated:  January 12, 2000

                                                  FOCAL COMMUNICATIONS
                                                  CORPORATION

                                                  by___________________
                                                    Name:
                                                    Title:

Attest:

______________________

                                       3
<PAGE>

                               (REVERSE OF NOTE)

                     11 7/8% Senior Discount Note Due 2010

     1.   Indenture.
          ---------

     This Note is one of a duly authorized issue of Notes of the Company
designated as its 11.875% Senior Notes due January 15, 2010 (the "Notes"),
                                                                  -----
issued under an indenture, dated as of January 12, 2000 (herein, as amended from
time to time, called the "Indenture"), between the Company and Harris Trust and
                          ---------
Savings Bank, as trustee (herein called the "Trustee", which term includes any
                                             -------
successor trustee under the Indenture).  The Notes are limited in aggregate
principal amount to $275,000,000.  Reference is hereby made to the Indenture and
all indentures supplemental thereto for a statement of the respective rights,
limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Holder of this Note and of the terms upon which this Note is,
and is to be, authenticated and delivered.  All terms used in this Note which
are defined in the Indenture shall have the meanings assigned to them in the
Indenture.

     2.   Principal Amount and Interest.
          -----------------------------

          The Company will pay the principal amount of this Note on January 15,
2010.

          This Note will bear interest on the outstanding aggregate principal
amount thereof at a rate of 11.875 % per annum computed on a semiannual bond
equivalent basis from the Issue Date.

          If (i) the Company has not filed a registration statement (the
"Exchange Offer Registration Statement") under the Securities Act of 1933, as
 -------------------------------------
amended (the "Securities Act"), registering a security substantially identical
              --------------
to this Note (except that such Note will not contain terms with respect to
transfer restrictions) pursuant to an exchange offer (the "Registered Exchange
                                                           -------------------
Offer") on or prior to April 14, 2000 or (ii) the Exchange Offer Registration
-----
Statement relating to the Registered Exchange Offer has not become or been
declared effective prior to August 12, 2000, or (iii) neither the Registered
Exchange Offer has been consummated nor a registration statement registering
this Note for resale (a "Shelf Registration Statement") has been declared
                         ----------------------------
effective prior to September 11, 2000 or (iv) after the Shelf Registration
Statement has been declared effective, such Shelf Registration Statement
thereafter ceases to be effective or usable (subject to certain exceptions set
forth in the Registration Agreement) in connection with resales of this Note or
notes issued in exchange for this Note pursuant to the Registered Exchange Offer
("Exchange Notes") in accordance with and during the periods specified in the
  --------------
Registration Agreement without being succeeded promptly by an additional
registration statement filed and declared effective, in the case of each of the
immediately preceding clauses (i) through (iv) upon the terms and conditions set
forth in the Registration Agreement (each such event referred to in such clauses
(i) through (iv), a "Registration Default"), then interest will accrue on this
                     --------------------
Note and the Exchange Notes (in addition to the stated interest on this Note and
the Exchange Notes) (the "Step-Up") and be payable in cash semiannually in
                          -------
arrears on January 15 and July 15 of each year, beginning on the January 15 or
July 15 immediately following a Registration Default (such interest to be
payable to the Holder of record as of the January 1 and July 1, as the case may
be, immediately preceding January 15 or July 15), at a rate of 0.50% per annum
during the 90-day period immediately following the occurrence of a Registration
Default and shall increase by a rate per annum equal to 0.25% at the end of each
subsequent 90-day period.  In no event shall such rate exceed 1.50% per annum in
the aggregate regardless of the number of Registration Defaults.

                                       4
<PAGE>

          The Company shall pay interest on overdue principal and premium, if
any, and interest on overdue installments of interest, to the extent lawful, at
a rate per annum equal to the interest rate payable on this Note.

          Any such interest not so punctually paid or duly provided for will
forthwith cease to be payable to the Holder on such Regular Record Date and may
either be paid to the Person in whose name this Note (or one or more Predecessor
Notes) is registered at the close of business on a Special Record Date for the
payment of such Defaulted Interest to be fixed by the Trustee, notice of which
shall be given to the Holder of this Note not less than 10 calendar days prior
to such Special Record Date.

     3.   Method of Payment.
          ------------------

          The Company will pay principal, premium, if any, and as provided
above, interest in money of the United States that at the time of payment is
legal tender for payment of public and private debts.  Payments in respect of
Notes represented by Global Notes (including principal, premium, interest and
Defaulted Interest, if any) will be made by wire transfer of immediately
available funds to the accounts specified by the nominee for the Depositary.
With respect to certificated Notes, the Paying Agent will make all payments of
principal, premium, interest and Defaulted Interest, if any, by wire transfer of
immediately available funds to the United States dollar accounts maintained by
the Holders entitled thereto with banks in the United States, or, if no such
account is designated by the relevant Holder to the Trustee or the Paying Agent
at least 30 days prior to the relevant due date for payment (or such other date
as the Trustee may accept in its discretion), by mailing a check to the
registered address of such Holder.  If a payment date is a date other than a
Business Day at a place of payment, payment may be made at that place on the
next succeeding day that is a Business Day and no interest shall accrue for the
intervening period.

     4.   Paying Agent and Note Registrar.
          --------------------------------

          Initially, the Trustee will act as authenticating agent, Paying Agent
and Note Registrar.  The Trustee may be removed by action of the Holders of not
less than a majority in principal amount of the outstanding Notes, or by the
Company or certain bona fide Holders of Notes upon the occurrence of certain
events.  The Company may change any Paying Agent or Note Registrar with notice
in writing to the Trustee.  The Company, any Subsidiary or any Affiliate of
either of them may act as Paying Agent or Note Registrar.

     5.   Optional Redemption.
          --------------------

          This Note is subject to redemption upon not less than 30 nor more than
60 days' prior written notice to each Holder of Notes to be redeemed at such
Holder's address appearing in the Note Register, in principal amounts or at any
time on or after January 15, 2005, at the following Redemption Prices plus
accrued and unpaid interest, if any, thereon to but excluding the  Redemption
Date, if redeemed during the periods indicated below:

<TABLE>
<CAPTION>
     From and Including       To and Including         Redemption Price
     ------------------       ----------------         ----------------
   <S>                        <C>                      <C>
   January 15, 2005           January 14, 2006              105.938%
   January 15, 2006           January 14, 2007              103.958%
   January 15, 2007           January 14, 2008              101.979%
</TABLE>

                                       5
<PAGE>

   January 15, 2008 and thereafter                          100.000%

          This Note will be redeemable at any time and from time to time prior
to January 15, 2003 in the event that the Company receives Net Cash Proceeds
from the sale of its Capital Stock (other than Disqualified Stock) in one or
more Public Equity Offerings, in which case the Company may, at its option, use
all or a portion of any such Net Cash Proceeds to redeem up to 35% of initially
outstanding aggregate principal amount of the Notes; provided, that at least 65%
                                                     --------
of the original aggregate principal amount of the Notes remains outstanding
after each such redemption.  Such redemption must occur on a date of redemption
within 90 days of such sale and upon not less than 30 nor more than 60 days'
prior written notice, in  principal amounts of $1,000 or integral multiples
thereof at a redemption price equal to 111.875% of the principal amount of the
Notes to be redeemed plus Additional Interest, if any, to but excluding the date
of redemption.

          If, after giving effect to the offer by the Company to repurchase all
or any part of each Holder's Notes made upon the occurrence of a Change of
Control as set forth in Section 7 hereto, at least 95% of the original aggregate
principal amount of the Notes has been redeemed or repurchased pursuant to the
Indenture, the Company shall have the right to redeem the balance of the Notes
at a redemption price equal to 101% of the principal amount thereof plus accrued
and unpaid interest, if any, thereon to but excluding the date of redemption.
The Company may exercise this right by giving the Holders notice of such
redemption within 30 days following the payment date with respect to the
Company's earlier repurchase offer.

     6.   No Sinking Fund.
          ----------------

          The Notes do not have the benefit of any sinking fund obligations.

     7.   Repurchase of Notes at the Option of Holders upon a Change of Control.
          ----------------------------------------------------------------------

          Upon the occurrence of a Change of Control, each Holder will have the
right to require the Company to repurchase all or any part (equal to $1,000
principal amount or an integral multiple thereof) of such Holder's Notes at a
purchase price ("Change of Control Purchase Price") equal to 101% of the
                 --------------------------------
principal amount thereof plus accrued and unpaid interest, if any, thereon to
but excluding the payment date for the Change of Control Purchase Price.

          Within 30 days following any Change of Control, the Company or the
Trustee (at the expense of the Company) shall mail a notice to each Holder
regarding the Company's offer to repurchase all or any part of such Holder's
Notes.  The Holder of this Note may elect to have this Note or a portion hereof
in an authorized denomination purchased by completing the form entitled "Option
of Holder to Elect Purchase" appearing below and tendering this Note pursuant to
the offer described in the notice.  Unless the Company defaults in the payment
of the Change of Control Purchase Price with respect thereto, all Notes or
portions thereof accepted for payment pursuant to the offer described in the
notice will cease to accrue interest from and after the payment date for the
Change of Control Purchase Price.

     8.   Repurchase of Notes at the Option of Holders upon an Asset Sale.
          ----------------------------------------------------------------

          If at any time the Company or any Restricted Subsidiary engages in any
Asset Sale, as a result of which the aggregate amount of Excess Proceeds
calculated as of any date exceeds $5,000,000, the Company shall, within 30 days
of such date, make an offer to purchase (an "Asset Sale Offer") on a pro rata
                                             ----------------
basis (a) Notes at a purchase price (the

                                       6
<PAGE>

"Offer Purchase Price") in cash equal to 100% of the principal amount thereof,
 --------------------
plus accrued and unpaid interest thereon, if any, to but excluding the purchase
date and (b) to the extent required by the terms thereof, any other indebtedness
of the Company that is pari passu with the Notes. The pro rata amount of such
Excess Proceeds to be used to purchase Notes shall be in an amount equal to the
aggregate amount of such Excess Proceeds multiplied by the quotient obtained by
dividing the principal amount of the outstanding Notes by the sum of such
principal amount and the principal amount of such other Indebtedness. In the
event the aggregate Offer Purchase Price of the outstanding Notes tendered
pursuant to an Asset Sale Offer is in excess of the Excess Proceeds to be used
to purchase such Notes, such Excess Proceeds shall be applied to purchase such
Notes on a pro rated basis in principal amounts of $1,000 or an integral
multiple thereof.

          Within 30 days of the date the amount of Excess Proceeds exceeds
$5,000,000, the Company or the Trustee (at the expense of the Company) shall
mail to each Holder a written notice regarding the Asset Sale Offer.  The Holder
of this Note may elect to have this Note or a portion hereof in an authorized
denomination purchased by completing the form entitled "Option of Holder to
Elect Purchase" appearing below and tendering this Note pursuant to the Asset
Sale Offer.  Unless the Company defaults in the payment of the Offer Purchase
Price with respect thereto, all Notes or portions thereof selected for payment
pursuant to the Asset Sale Offer will cease to accrue interest from and after
the purchase date.

     9.   Denominations; Transfer; Exchange.
          ----------------------------------

          The Notes are issuable only in registered form without coupons in
denominations of $1,000 principal amount and any integral multiple thereof.  A
Holder may register the transfer or exchange of Notes in accordance with the
Indenture.  No service charge shall be made for any such registration of
transfer or exchange, but the Company may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

     10.  Persons Deemed Owners.
          ----------------------

          Prior to due presentment of this Note for registration of transfer,
the Company, the Trustee, the Paying Agent and the Note Registrar may deem and
treat the Person in whose name this Note is registered as the owner hereof for
all purposes, whether or not this Note be overdue, and none of the Company, the
Trustee, the Paying Agent or the Note Registrar shall be affected by notice to
the contrary.

     11.  Unclaimed Money.
          ----------------

          Subject to certain notice provisions, the Trustee and the Paying Agent
shall pay to the Company upon written request any money held by them for the
payment of principal, premium, if any, or interest that remains unclaimed for
two years.  After payment to the Company, Holders entitled to such money must
look only to the Company for payment as general creditors, and all
responsibility and liability of the Trustee and the Paying Agent with respect to
such money shall cease.

     12.  Discharge Prior to Redemption.
          ------------------------------

          If the Company deposits with the Trustee United States dollars or U.S.
Government Obligations sufficient to pay the principal, premium, if any, and
accrued interest on the Notes to redemption, the Company will, with the
exceptions of certain

                                       7
<PAGE>

sections thereof, be discharged from the Indenture and the Notes, including
certain covenants set forth in the Indenture.

     13.  Amendment; Waiver.
          ------------------

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Notes under the Indenture at any
time by the Company and the Trustee with the consent of the Holders of not less
than a majority in aggregate principal amount of the Notes at the time
outstanding.  The Indenture also contains provisions permitting the Holders of
not less than a majority in aggregate principal amount of the Notes at the time
outstanding, on behalf of the Holders of all the Notes, to waive certain past
defaults under the Indenture and their consequences.

     14.  Restrictive Covenants.
          ----------------------

          The Indenture contains certain covenants which, among other things,
restrict the ability of the Company and Restricted Subsidiaries to incur
additional indebtedness (and, in the case of Restricted Subsidiaries, issue
preferred stock), pay dividends or make distributions in respect of the
Company's or Restricted Subsidiaries' capital stock, make other restricted
payments, enter into sale and leaseback transactions, incur liens, cause
encumbrances or restrictions to exist on the ability of Restricted Subsidiaries
to pay dividends or make distributions in respect of their capital stock, issue
and sell capital stock of Restricted Subsidiaries, enter into transactions with
affiliates, sell assets, or amalgamate, consolidate, merge or sell or otherwise
dispose of all or substantially all of their property and assets.

     15.  Defaults and Remedies.
          ----------------------

          With the exception of certain Events of Defaults specified below, if
an Event of Default occurs and is continuing, the Trustee or the Holders of not
less than 25% of the aggregate principal amount of the outstanding Notes may
declare the principal amount of, and any accrued and unpaid interest on, all
Notes then outstanding to be immediately due and payable.  If a bankruptcy or
insolvency default with respect to the Company or a Restricted Subsidiary occurs
and is continuing, the Notes immediately become due and payable.  Holders may
not enforce the Indenture or the Notes except as provided in the Indenture.  The
Trustee may require indemnity satisfactory to it before it enforces the
Indenture or the Notes.  Subject to certain limitations, Holders of not less
than a majority in principal amount of the outstanding Notes will have the right
to direct the time, method and place of conducting any proceeding for exercising
any remedy available to the Trustee.

     16.  No Recourse Against Others.
          ---------------------------

          No controlling Person, director, officer, employee, incorporator or
stockholder of the Company, as such, shall have any liability for any covenant,
agreement or other obligations of the Company under the Notes or the Indenture
or for any claim based on, in respect of, or by reason of, such obligations or
their creation, solely by reason of its past, present or future status as a
controlling Person, director, officer, employee, incorporator or stockholder of
the Company.  Each Holder by accepting a Note waives and releases all such
liability (but only such liability).  The waiver and release are part of the
consideration for the issuance of the Notes.

                                       8
<PAGE>

     17.  Governing Law.
          --------------

          THIS SECURITY SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE LAWS OF THE STATE OF NEW YORK BUT WITHOUT GIVING EFFECT TO APPLICABLE
PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF
ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

          The Company will furnish to any Holder upon written request and
without charge to the Holder a copy of the Indenture.  Requests may be made to:

          Focal Communications Corporation
          200 N. LaSalle
          Chicago, Illinois 60601
          Attention:  Chief Financial Officer

     18.  Ranking.
          --------

          The Notes are senior unsecured obligations of the Company ranking pari
passu in right of payment with all existing and future senior indebtedness of
the Company, and will rank senior in right of payment to all existing and future
subordinated Indebtedness of the Company.  Holders of secured Indebtedness of
the Company, however, will have claims that are prior to the claims of the
Holders with respect to the assets securing such other indebtedness except to
the extent the Notes are equally and ratably secured by such assets.

                                       9
<PAGE>

______________________________________________________________________

                            CERTIFICATE OF TRANSFER

To assign this Note, fill in the form below:

I or we assign and transfer this Note to

     (Print or type assignee's name, address and zip code)

     (Insert assignee's soc. sec. or tax I.D. No.)

and irrevocably appoint                           agent to transfer this Note on
the books of Focal Communications Corporation.  The agent may substitute another
to act for him.

______________________________________________________________________

Date: ________________ Your Signature: _____________________

______________________________________________________________________
Sign exactly as your name appears on the other side of this Note.

                                       10
<PAGE>

In connection with any transfer of any of the Notes evidenced by this
certificate occurring prior to the expiration of the period referred to in Rule
144(k) under the Securities Act of 1933 (the "Securities Act") after the later
of the date of original issuance of such Notes and the last date, if any, on
which such Notes were owned by Focal Communications Corporation or any
Affiliate, the undersigned confirms that such Notes are being transferred in
accordance with the terms of such Notes:

CHECK ONE BOX BELOW

     (1)  [_]  to Focal Communications Corporation; or

     (2)  [_]  pursuant to an effective registration statement under the
               Securities Act; or

     (3)  [_]  inside the United States to a "qualified institutional buyer" (as
                                              -----------------------------
               defined in Rule 144A under the Securities Act of 1933) that
               purchases for its own account or for the account of a qualified
               institutional buyer to whom notice is given that such transfer is
               being made in reliance on Rule 144A under the Securities Act, in
               each case pursuant to and in compliance with Rule 144A under the
               Securities Act; or

     (4)  [_]  outside the United States in an offshore transaction within the
               meaning of Regulation S under the Securities Act in compliance
               with Rule 904 under the Securities Act;

     (5)  [_]  pursuant to another available exemption from registration
               provided by Rule 144 under the Securities Act; or

     (6)  [_]  to an institution that is an "accredited investor" as defined in
               Rule 501(a)(1), (2), (3) or (7) under the Securities Act that is
               acquiring this Note for investment purposes and not for
               distribution in violation of the Securities Act or any other
               applicable securities laws.

     Unless one of the boxes is checked, the Trustee will refuse to register any
     of the Notes evidenced by this certificate in the name of any person other
     than the registered holder thereof; provided, however, that if box (3),
                                         --------  -------
     (4), (5) or (6) is checked, the Trustee may require, prior to registering
     any such transfer of the Notes, such legal opinions, certifications and
     other information as the Company has reasonably requested to confirm that
     such transfer is being made pursuant to an exemption from, or in a
     transaction not subject to, the registration requirements of the Securities
     Act, such as the exemption provided by Rule 144 under the Securities Act.

                                       11
<PAGE>

______________________
Signature

Signature Guarantee:

_______________________                      _____________________________
[Signature must be guaranteed                Signature
by an eligible Guarantor
Institution (banks, stock
brokers, savings and loan
associations and credit
unions) with membership in
an approved guarantee
medallion program pursuant
to Securities and Exchange
Commission Rule 17Ad-15]

____________________________________________________________

             TO BE COMPLETED BY PURCHASER IF (3) ABOVE IS CHECKED.

          The undersigned represents and warrants that it is purchasing this
Note for its own account or an account with respect to which it exercises sole
investment discretion and that it and any such account is a "qualified
                                                             ---------
institutional buyer" within the meaning of Rule 144A under the Securities Act,
-------------------
and is aware that the sale to it is being made in reliance on Rule 144A under
the Securities Act and acknowledges that it has received such information
regarding the Company as the undersigned has requested pursuant to Rule 144A
under the Securities Act or has determined not to request such information and
that it is aware that the transferor is relying upon the foregoing
representations of the undersigned in order to claim the exemption from
registration provided by Rule 144A under the Securities Act.

Dated: ________________       ______________________________________________
                              NOTICE: To be executed by an executive officer

                                       12
<PAGE>

               SCHEDULE OF INCREASES OR DECREASES IN GLOBAL NOTE

          The following increases or decreases in this Global Note have been
made:

<TABLE>
<CAPTION>
                                                                         Principal Amount of this
                     Amount of decrease in    Amount of increase in      Global Note following      Signature of authorized
Date of                 Principal Amount         Principal Amount           such decrease or        signatory  of Trustee or
Exchange              of this Global Note      of this Global Note              increase                 Notes Custodian
--------            -----------------------  -----------------------  ---------------------------  -------------------------
<S>                 <C>                      <C>                      <C>                          <C>
</TABLE>

                                       13
<PAGE>

                      OPTION OF HOLDER TO ELECT PURCHASE

          If you want to elect to have this Note purchased by the Company
pursuant to Section 4.07 or 4.08 of the Indenture, check the box:

                                        [_]

          If you want to elect to have only part of this Note purchased by the
Company pursuant to Section 4.07 or 4.08 of the Indenture, state the amount in
principal amount ($1,000 or an integral multiple thereof): $

Date: _______________    Your Signature:       __________________
                                               (Sign exactly as your name
                                               appears on the other side of
                                               this Note)

Signature Guarantee: _______________________________________
                     Signature must be guaranteed by an eligible Guarantor
                     Institution (banks, stock brokers, savings and loan
                     associations and credit unions) with membership in an
                     approved guarantee medallion program pursuant to Securities
                     and Exchange Commission Rule 17Ad-15.

                                       14
<PAGE>

          Harris Trust and Savings Bank, as Trustee, certifies that this is one
of the Notes referred to in the within-mentioned Indenture.

     Date: January 12, 2000

                                             HARRIS TRUST AND SAVINGS BANK,
                                                as Trustee

                                             by_______________________
                                               Authorized Signatory

                                       15

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