<PAGE>
 
                                                                  Exhibit 4.2(a)

                                                                  EXECUTION COPY

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


                                  MEDIACOM LLC

                                      and

                          MEDIACOM CAPITAL CORPORATION

                                   as Issuers

                                      and

                        BANK OF MONTREAL TRUST COMPANY,

                                   as Trustee


                             _____________________



                                   Indenture

                                        
                             ______________________

                         Dated as of  February 26, 1999


                         7 7/8% Senior Notes due 2011

--------------------------------------------------------------------------------
<PAGE>
 
               Reconciliation and tie between Trust Indenture Act
             of 1939 and Indenture, dated as of February 26, 1999/1/


Trust Indenture
Act Section                   Indenture Section

(S) 310(a)(1)...............................................................608
(S) 310(a)(2)...............................................................608
(S) 310(b)..................................................................609
(S) 312(a)..................................................................701
(S) 312(c)..................................................................702
(S) 313(a)..................................................................703
(S) 313(c)..................................................................703
(S) 314(a)(4)...........................................................1010(a)
(S) 314(c)(1)...............................................................102
(S) 314(c)(2)...............................................................102
(S) 314(e)..................................................................102
(S) 315(a)..............................................................601 (a)
(S) 315(b)..................................................................602
(S) 315(c)..............................................................601 (b)
(S) 315(d).........................................................601 (c), 603
(S) 316(a)(last sentence....................................101 ("outstanding")
(S) 316(a)(a)(1)(A)....................................................502, 512
(S) 316(a)(a)(1)(B).........................................................513
(S) 316(a)(b)...............................................................508
(S) 316(a)(c)............................................................104(d)
(S) 317(a)(1)...............................................................503
(S) 317(a)(2)...............................................................504
(S) 317(b).................................................................1003
(S) 318(a)..................................................................111

--------------------
/1/ This reconciliation and tie shall not, for any purpose, be deemed to be a
    part of the Indenture.
<PAGE>
                               TABLE OF CONTENTS:
<TABLE>
<CAPTION>
                                                                                                                                PAGE
                                                                                                                                ----
<S>                          <C>                                                                                                <C>
ARTICLE ONE. DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION                                                               1

SECTION 101.                 Definitions........................................................................................   1
                             -----------
SECTION 102.                 Compliance Certificates and Opinions...............................................................  17
                             ------------------------------------
SECTION 103.                 Form of Documents Delivered to Trustee.............................................................  18
                             --------------------------------------
SECTION 104.                 Acts of Holders....................................................................................  18
                             ---------------
SECTION 105.                 Notices, Etc., to Trustee and the Issuers..........................................................  19
                             -----------------------------------------
SECTION 106.                 Notice to Holders; Waiver..........................................................................  19
                             ------------------------
SECTION 107.                 Effect of Headings and Table of Contents...........................................................  20
                             ----------------------------------------
SECTION 108.                 Successors and Assigns.............................................................................  20
                             ----------------------
SECTION 109.                 Separability Clause................................................................................  20
                             -------------------
SECTION 110.                 Benefits of Indenture..............................................................................  20
                             ---------------------
SECTION 111.                 Governing Law......................................................................................  20
                             -------------
SECTION 112.                 Legal Holidays.....................................................................................  21
                             --------------
SECTION 113.                 No Personal Liability of Directors, Officers, Employees, Stockholders or Incorporators.............  21
                             --------------------------------------------------------------------------------------
SECTION 114.                 Counterparts.......................................................................................  21
                             ------------
SECTION 115.                 Communications by Holders with Other Holders.......................................................  21
                             --------------------------------------------
ARTICLE TWO. NOTE FORMS.........................................................................................................  21

SECTION 201.                 Forms Generally....................................................................................  21
                             ---------------
SECTION 202.                 Restrictive Legends................................................................................  22
                             -------------------
SECTION 203.                 Form of Note.......................................................................................  26
                             ------------
SECTION 204.                 Form of Trustee's Certificate of Authentication....................................................  39
                             -----------------------------------------------
ARTICLE THREE. THE NOTES........................................................................................................  40

SECTION 301.                 Title and Terms....................................................................................  40
                             ---------------
SECTION 302.                 Denominations......................................................................................  40
                             -------------
SECTION 303.                 Execution, Authentication, Delivery and Dating.....................................................  41
                             ----------------------------------------------
SECTION 304.                 Temporary Notes....................................................................................  42
                             ---------------
SECTION 305.                 Registration, Registration of Transfer and Exchange................................................  42
                             ---------------------------------------------------
SECTION 306.                 Book-Entry Provisions for Global Notes.............................................................  43
                             --------------------------------------
SECTION 307.                 Special Transfer Provisions........................................................................  44
                             ---------------------------
SECTION 308.                 Form of Certificate to Be Delivered in Connection with Transfers to Institutional Accredited         47
                             Investors..........................................................................................
                             ---------
SECTION 309.                 Form of Certificate to Be Delivered in Connection with Transfers Pursuant to Regulation S..........  49
                             -----------------------------------------------------------------------------------------
SECTION 310.                 Mutilated, Destroyed, Lost and Stolen Notes........................................................  50
                             -------------------------------------------
SECTION 311.                 Payment of Interest; Interest Rights Preserved.....................................................  50
                             ----------------------------------------------
SECTION 312.                 Persons Deemed Owners..............................................................................  51
                             ---------------------
SECTION 313.                 Cancellation.......................................................................................  52
                             ------------
SECTION 314.                 Computation of Interest............................................................................  52
                             -----------------------
SECTION 315.                 CUSIP Numbers......................................................................................  52
                             -------------
ARTICLE FOUR. SATISFACTION AND DISCHARGE........................................................................................  52

SECTION 401.                 Satisfaction and Discharge of Indenture............................................................  52
                             ---------------------------------------
SECTION 402.                 Application of Trust Money.........................................................................  53
                             --------------------------
ARTICLE FIVE. REMEDIES..........................................................................................................  54

SECTION 501.                 Events of Default..................................................................................  54
                             -----------------
SECTION 502.                 Acceleration of Maturity; Rescission and Annulment.................................................  56
                             --------------------------------------------------
SECTION 503.                 Collection of Indebtedness and Suits for Enforcement by Trustee....................................  56
                             ---------------------------------------------------------------
</TABLE>
<PAGE>
 
<TABLE>
<CAPTION>
<S>                          <C>                                                                                                <C>
SECTION 504.                 Trustee May File Proofs of Claim...................................................................  56
                             --------------------------------
SECTION 505.                 Trustee May Enforce Claims Without Possession of Notes.............................................  57
                             ------------------------------------------------------
SECTION 506.                 Application of Money Collected.....................................................................  57
                             ------------------------------
SECTION 507.                 Limitation on Suits................................................................................  58
                             -------------------
SECTION 508.                 Unconditional Right of Holders to Receive Principal, Premium and Interest..........................  58
                             -------------------------------------------------------------------------
SECTION 509.                 Restoration of Rights and Remedies.................................................................  58
                             ----------------------------------
SECTION 510.                 Rights and Remedies Cumulative.....................................................................  59
                             ------------------------------
SECTION 511.                 Delay or Omission Not Waiver.......................................................................  59
                             ----------------------------
SECTION 512.                 Control by Holders.................................................................................  59
                             ------------------
SECTION 513.                 Waiver of Past Defaults............................................................................  59
                             -----------------------
SECTION 514.                 Undertaking for Costs..............................................................................  60
                             ---------------------
ARTICLE SIX. THE TRUSTEE........................................................................................................  60

SECTION 601.                 Certain Duties and Responsibilities................................................................  60
                             -----------------------------------
SECTION 602.                 Notice of Defaults.................................................................................  61
                             ------------------
SECTION 603.                 Certain Rights of Trustee..........................................................................  61
                             -------------------------
SECTION 604.                 Trustee Not Responsible for Recitals or Issuance of Notes..........................................  63
                             ---------------------------------------------------------
SECTION 605.                 May Hold Notes.....................................................................................  63
                             --------------
SECTION 606.                 Money Held in Trust................................................................................  63
                             -------------------
SECTION 607.                 Compensation and Reimbursement.....................................................................  63
                             ------------------------------
SECTION 608.                 Corporate Trustee Required; Eligibility............................................................  64
                             ---------------------------------------
SECTION 609.                 Resignation and Removal; Appointment of Successor..................................................  64
                             -------------------------------------------------
SECTION 610.                 Acceptance of Appointment by Successor.............................................................  65
                             --------------------------------------
SECTION 611.                 Merger, Conversion, Consolidation or Succession to Business........................................  66
                             -----------------------------------------------------------
SECTION 612.                 Trustee's Application for Instructions from the Issuers............................................  66
                             -------------------------------------------------------
ARTICLE SEVEN. HOLDERS LISTS AND REPORTS BY TRUSTEE AND THE ISSUERS.............................................................  67

SECTION 701.                 The Issuers to Furnish Trustee Names and Addresses.................................................  67
                             --------------------------------------------------
SECTION 702.                 Disclosure of Names and Addresses of Holders.......................................................  67
                             --------------------------------------------
SECTION 703.                 Reports by Trustee.................................................................................  67
                             ------------------
ARTICLE EIGHT. MERGER, CONSOLIDATION, OR SALE OF ASSETS.........................................................................  68

SECTION 801.                 The Issuers and Guarantors May Consolidate Etc. Only on Certain Terms..............................  68
                             ---------------------------------------------------------------------
SECTION 802.                 Successor Substituted..............................................................................  69
                             ---------------------
ARTICLE NINE. SUPPLEMENTS, AMENDMENTS AND MODIFICATIONS TO INDENTURE............................................................  69

SECTION 901.                 Supplemental Indentures Without Consent of Holders.................................................  69
                             --------------------------------------------------
SECTION 902.                 Supplemental Indentures with Consent of Holders....................................................  70
                             -----------------------------------------------
SECTION 903.                 Execution of Supplemental Indentures...............................................................  70
                             ------------------------------------
SECTION 904.                 Effect of Supplemental Indentures..................................................................  71
                             ---------------------------------
SECTION 905.                 Conformity with Trust Indenture Act................................................................  71
                             -----------------------------------
SECTION 906.                 Reference in Notes to Supplemental Indentures......................................................  71
                             ---------------------------------------------
SECTION 907.                 Notice of Supplemental Indentures..................................................................  71
                             ---------------------------------
ARTICLE TEN. COVENANTS..........................................................................................................  71

SECTION 1001.                Payment of Principal, Premium, if any, and Interest................................................  71
                             ---------------------------------------------------
SECTION 1002.                Maintenance of Office or Agency....................................................................  71
                             -------------------------------
SECTION 1003.                Money for Note Payments to Be Held in Trust........................................................  72
                             -------------------------------------------
SECTION 1004.                Corporate Existence................................................................................  73
                             -------------------
SECTION 1005.                Payment of Taxes and Other Claims..................................................................  73
                             ---------------------------------
SECTION 1006.                Compliance with Laws...............................................................................  73
                             --------------------
SECTION 1007.                Limitation on Restricted Payments..................................................................  74
                             ---------------------------------
SECTION 1008.                Limitation on Indebtedness.........................................................................  75
                             --------------------------
SECTION 1009.                Limitation on Affiliate Transactions...............................................................  78
                             ------------------------------------
SECTION 1010.                Limitation on Dividends and Other Payment Restrictions Affecting Subsidiaries......................  79
                             -----------------------------------------------------------------------------
</TABLE>
<PAGE>
 
<TABLE>
<CAPTION>
<S>                          <C>                                                                                                <C>
SECTION 1011.                Limitation on Liens................................................................................  79
                             -------------------
SECTION 1012.                Change of Control..................................................................................  80
                             -----------------
SECTION 1013.                Limitation on Sales of Assets......................................................................  81
                             -----------------------------
SECTION 1014.                Reports............................................................................................  82
                             -------
SECTION 1015.                Limitation on Business Activities of Mediacom Capital..............................................  82
                             -----------------------------------------------------
SECTION 1016.                Statement by Officers as to Default................................................................  83
                             -----------------------------------
SECTION 1017.                Limitation on Guarantees of Certain Indebtedness...................................................  83
                             ------------------------------------------------
SECTION 1018.                Designation of Unrestricted Subsidiaries...........................................................  84
                             ----------------------------------------
ARTICLE ELEVEN. REDEMPTION OF NOTES.............................................................................................  85

SECTION 1101.                Optional Redemption................................................................................  85
                             -------------------
SECTION 1102.                Applicability of Article...........................................................................  85
                             ------------------------
SECTION 1103.                Election to Redeem; Notice to Trustee..............................................................  85
                             -------------------------------------
SECTION 1104.                Selection by Trustee of Notes to Be Redeemed.......................................................  85
                             --------------------------------------------
SECTION 1105.                Notice of Redemption...............................................................................  85
                             --------------------
SECTION 1106.                Deposit of Redemption Price........................................................................  86
                             ---------------------------
SECTION 1107.                Notes Payable on Redemption Date...................................................................  87
                             --------------------------------
SECTION 1108.                Notes Redeemed in Part.............................................................................  87
                             ----------------------
ARTICLE TWELVE.              DEFEASANCE AND COVENANT DEFEASANCE.................................................................  87

SECTION 1201.                The Issuers' Option to Effect Defeasance or Covenant Defeasance....................................  87
                             ---------------------------------------------------------------
SECTION 1202.                Defeasance and Discharge...........................................................................  87
                             ------------------------
SECTION 1203.                Covenant Defeasance................................................................................  88
                             -------------------
SECTION 1204.                Conditions to Defeasance or Covenant Defeasance....................................................  88
                             -----------------------------------------------
SECTION 1205.                Deposited Money and U.S. Government Obligations to Be Held in Trust; Other Miscellaneous             90
                             Provisions.........................................................................................
                             ----------
SECTION 1206.                Reinstatement......................................................................................  90
                             -------------
ARTICLE THIRTEEN. RESTRICTED SUBSIDIARY GUARANTEE                                                                                 90

SECTION 1301.                Unconditional Guarantee............................................................................  90
                             -----------------------
SECTION 1302.                Severability.......................................................................................  91
                             ------------
SECTION 1303.                Limitation of Guarantor's Liability................................................................  91
                             -----------------------------------
SECTION 1304.                Contribution.......................................................................................  91
                             ------------
SECTION 1305.                Additional Guarantors..............................................................................  92
                             ---------------------
SECTION 1306.                Subordination of Subrogation and Other Rights......................................................  92
                             ---------------------------------------------

</TABLE>
<PAGE>
 
          INDENTURE, dated as of February 26, 1999 between MEDIACOM LLC, a New
York limited liability company ("Mediacom"), MEDIACOM CAPITAL CORPORATION, a New
York corporation ("Mediacom Capital" and together with Mediacom, the "Issuers"),
as joint and several obligors, each having its principal office at 100 Crystal
Run Road, Middletown, New York 10941, and BANK OF MONTREAL TRUST COMPANY, a New
York trust company, as trustee (the "Trustee"), having its principal corporate
trust office at 88 Pine Street, New York, NY 10005.

                            RECITALS OF THE ISSUERS

          The Issuers have duly authorized the creation of and issuance of (i)
7 7/8% Senior Notes due 2011 (the "Initial Notes") and (ii) if and when issued
in exchange for notes as provided in the Registration Rights Agreement (as
defined herein), 7 7/8% Senior Notes due 2011 (the "Exchange Notes") (the
Initial Notes, the Exchange Notes, the Private Exchange Notes (as defined
herein) and the Additional Notes (as defined herein) are referred to herein
collectively as the "Notes"), of substantially the tenor and amount hereinafter
set forth, and to provide therefor the Issuers have duly authorized the
execution and delivery of this Indenture. "Exchange Notes" and "Private Exchange
Notes" shall include notes issued in exchange for Additional Notes having
substantially the same tenor and amount as the Additional Notes.

          Upon the issuance of the Exchange Notes, if any, or the effectiveness
of the Shelf Registration Statement (as defined herein), this Indenture will be
subject to, and shall be governed by, the provisions of the Trust Indenture Act
of 1939, as amended, that are required or deemed to be part of and to govern
indentures qualified thereunder.

          All things necessary have been done to make the Notes, when executed
and duly issued by the Issuers and authenticated and delivered hereunder by the
Trustee or the Authenticating Agent, the valid obligations of the Issuers and to
make this Indenture a valid agreement of the Issuers in accordance with their
and its terms.

          NOW, THEREFORE, THIS INDENTURE WITNESSETH:

          For and in consideration of the premises and the purchase of the Notes
by the Holders thereof, it is mutually covenanted and agreed, for the equal and
proportionate benefit of all Holders of the Notes, as follows:

                                  ARTICLE ONE.

            DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

          SECTION 101.  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 have the meanings assigned to
     them in this Article, and words in the singular include the plural as well
     as the singular, and words in the plural include the singular as well as
     the plural;

          (b) all other terms used herein which are defined in the Trust
     Indenture Act, either directly or by reference therein, or defined by SEC
     rule and not otherwise defined herein have the meanings assigned to them
     therein;
<PAGE>
 
          (c) all accounting terms not otherwise defined herein have the
     meanings assigned to them in accordance with GAAP (as defined herein);

          (d) the 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;

          (e) the word "or" is not exclusive; and

          (f) provisions of this Indenture apply to successive events and
     transactions.

          Certain terms, used principally in Articles Two, Ten and Twelve, are
     defined in those Articles.

          "8 1/2% Notes" means the Issuers' $200,000,000 8 1/2% Senior Notes due
     2008.

          "Acquired Indebtedness" means Indebtedness of a Person existing at the
time such Person becomes a Restricted Subsidiary or assumed in connection with
an Asset Acquisition from such Person and not Incurred in connection with, or in
anticipation of, such Person becoming a Restricted Subsidiary or such Asset
Acquisition.

          "Affiliate" means (i) any Person that directly, or indirectly through
one or more intermediaries, controls, or is controlled by, or is under common
control with, Mediacom; (ii) any spouse, immediate family member or other
relative who has the same principal residence as any Person described in clause
(i) above; (iii) any trust in which any such Persons described in clauses (i)
and (ii) above has a beneficial interest; and (iv) any corporation or other
organization of which any such Persons described above collectively owns 5% or
more of the equity of such entity. For purposes of this definition, "control"
(including, with correlative meaning, the terms "controlling," "controlled by"
and "under common control with") when used with respect to any specified Person
includes the direct or indirect beneficial ownership of more than 5% of the
voting securities of such Person or the power to direct or cause the direction
of the management and policies of such Person whether by contract or otherwise.

          "Asset Acquisition" means (i) an Investment by Mediacom or any
Restricted Subsidiary in any other Person pursuant to which such Person shall
become a Restricted Subsidiary or shall be consolidated or merged with or into
Mediacom or any Restricted Subsidiary, or (ii) any acquisition by Mediacom or
any Restricted Subsidiary of the assets of any Person which constitute
substantially all of an operating unit, a division or a line of business of such
Person or which is otherwise outside of the ordinary course of business.

          "Asset Sale" means any direct or indirect sale, conveyance, transfer,
lease (that has the effect of a disposition) or other disposition (including,
without limitation, any merger, consolidation or sale-leaseback transaction) to
any Person other than Mediacom or any Wholly Owned Restricted Subsidiary or any
Controlled Subsidiary, in one transaction or a series of related transactions,
of (i) any Equity Interest of any Restricted Subsidiary, (ii) any material
license, franchise or other authorization of Mediacom or any Restricted
Subsidiary, (iii) any assets of Mediacom or any Restricted Subsidiary which
constitute substantially all of an operating unit, a division or a line of
business of Mediacom or any Restricted Subsidiary or (iv) any other property or
asset of Mediacom or any Restricted Subsidiary outside of the ordinary course of
business. For the purposes of this definition, the term "Asset Sale" shall not
include (i) any transaction consummated in compliance with Sections 801 and
1012, and the creation of any Lien not prohibited under Section 1011, (ii) the
sale of property or equipment that has become worn out, obsolete or damaged or
otherwise unsuitable for use in connection with the business of Mediacom or any
Restricted Subsidiary, as the case may be, (iii) any transaction consummated in

                                       2
<PAGE>
 
compliance with Section 1007, and (iv) Asset Swaps permitted pursuant to clause
(d) of Section 1013.  In addition, solely for purposes of Section 1013, any
sale, conveyance, transfer, lease or other disposition, whether in one
transaction or a series of related transactions, involving assets with a fair
market value not in excess of $2,000,000 in any fiscal year shall be deemed not
to be an Asset Sale.

          "Asset Sale Proceeds" means, with respect to any Asset Sale, (i) cash
received by Mediacom or any of its Restricted Subsidiaries from such Asset Sale
(including cash received as consideration for the assumption of liabilities
incurred in connection with or in anticipation of such Asset Sale), after (a)
provision for all income or other taxes measured by or resulting from such Asset
Sale, (b) payment of all brokerage commissions, underwriting, legal, accounting
and other fees and expenses related to such Asset Sale, and any relocation
expenses incurred as a result thereof, (c) provision for minority interest
holders in any Restricted Subsidiary as a result of such Asset Sale by such
Restricted Subsidiary, (d) payment of amounts required to be applied to the
repayment of Indebtedness secured by a Lien on the asset or assets that were the
subject of such Asset Sale (including payments made to obtain or avoid the need
for the consent of any holder of such Indebtedness), and (e) deduction of
appropriate amounts to be provided by Mediacom or such Restricted Subsidiary as
a reserve, in accordance with generally accepted accounting principles
consistently applied, against any liabilities associated with the assets sold or
disposed of in such Asset Sale and retained by Mediacom or such Restricted
Subsidiary after such Asset Sale, including, without limitation, pension and
other post employment benefit liabilities and liabilities related to
environmental matters or against any indemnification obligations associated with
the assets sold or disposed of in such Asset Sale; and (ii) promissory notes and
other non-cash consideration received by Mediacom or any Restricted Subsidiary
from such Asset Sale or other disposition upon the liquidation or conversion of
such notes or non-cash consideration into cash.

          "Asset Swap" means the substantially concurrent purchase and sale, or
exchange, of Productive Assets between Mediacom or any of the Restricted
Subsidiaries and another Person or group of affiliated Persons (which Person or
group of affiliated Persons is not affiliated with Mediacom and the Restricted
Subsidiaries) pursuant to an Asset Swap Agreement; it being understood that an
Asset Swap may include a cash equalization payment made in connection therewith,
provided that such cash payment, if received by Mediacom or any of the
Restricted Subsidiaries, shall be deemed to be proceeds received from an Asset
Sale and shall be applied in accordance with Section 1013.

          "Asset Swap Agreement" means a definitive agreement, subject only to
customary closing conditions that Mediacom in good faith believes will be
satisfied, providing for an Asset Swap; provided, however, that any amendment
to, or waiver of, any closing condition that individually or in the aggregate is
material to such Asset Swap shall be deemed to be a new Asset Swap.

          "Available Asset Sale Proceeds" means, with respect to any Asset Sale,
the aggregate Asset Sale Proceeds from such Asset Sale that have not been
applied in accordance with clause (iii)(a) and that have not yet been the basis
for application in accordance with clause (iii)(b) of clause (a) of Section
1013.

          "Bankruptcy Law" means Title II, U.S. Code or any similar federal or
state law for relief of debtors.

          "Business Day" means a day other than a Saturday, Sunday or other day
on which commercial banking institutions are authorized or required by law to
close in New York City.

          "Capitalized Lease Obligations" means Indebtedness represented by
obligations under a lease that is required to be capitalized for financial
reporting purposes in accordance with generally accepted accounting principles
and the amount of such Indebtedness shall be the capitalized amount of

                                       3
<PAGE>
 
such obligations determined in accordance with generally accepted accounting
principles consistently applied.

          "Cash Equivalents" means (i) United States dollars; (ii) securities
issued or directly and fully guaranteed or insured by the United States
government or any agency or instrumentality thereof having maturities of not
more than six months from the date of acquisition; (iii) certificates of deposit
and eurodollar time deposits with maturities of six months or less from the date
of acquisition, bankers' acceptances with maturities not exceeding six months
and overnight bank deposits, in each case with any lender party to any
Subsidiary Credit Facility or any Future Subsidiary Credit Facility or with any
domestic commercial bank having capital and surplus in excess of $500,000,000;
(iv) repurchase obligations with a term of not more than seven days for
underlying securities of the types described in clauses (ii) and (iii) above
entered into with any financial institution meeting the qualifications specified
in clause (iii) above; (v) commercial paper having a rating of at least P-1 from
Moody's or a rating of at least A-1 from S&P; and (vi) money market mutual or
similar funds having assets in excess of $100,000,000, at least 95% of the
assets of which are comprised of assets specified in clauses (i) through (v)
above.

          "Change of Control" means the occurrence of any of the following
events: (i) any Person (as such term is used in Sections 13(d) and 14(d) 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)(1) under the
Exchange Act), other than one or more Permitted Holders, is or becomes the
"beneficial owner" (as defined in Rule 13d-3 and 13d-5 under the Exchange Act,
except that a Person shall be deemed to have "beneficial ownership" of all
shares that any such Person has the right to acquire, whether such right is
exercisable immediately or only after the passage of time, upon the happening of
an event or otherwise), directly or indirectly, of more than 50% of the total
voting power of the then outstanding Voting Equity Interests of Mediacom; (ii)
Mediacom consolidates with, or merges with or into, another Person (other than a
Wholly Owned Restricted Subsidiary) or Mediacom or any its Subsidiaries sells,
assigns, conveys, transfers, leases or otherwise disposes of all or
substantially all of the assets of Mediacom and its Subsidiaries (determined on
a consolidated basis) to any Person (other than Mediacom or any Wholly Owned
Restricted Subsidiary), other than any such transaction where immediately after
such transaction the Person or Persons that "beneficially owned" (as defined in
Rule 13d-3 and 13d-5 under the Exchange Act, except that a Person shall be
deemed to have "beneficial ownership" of all shares that any such Person has the
right to acquire, whether such right is exercisable immediately or only after
the passage of time, upon the happening of an event or otherwise) immediately
prior to such transaction, directly or indirectly, a majority of the total
voting power of the then outstanding Voting Equity Interests of Mediacom,
"beneficially own" (as so determined), directly or indirectly, more than 50% of
the total voting power of the then outstanding Voting Equity Interests of the
surviving or transferee Person; (iii) Mediacom is liquidated or dissolved or
adopts a plan of liquidation or dissolution (whether or not otherwise in
compliance with the provisions of this Indenture); (iv) a majority of the
members of the Executive Committee of Mediacom shall consist of Persons who are
not Continuing Members; or (v) Mediacom ceases to own 100% of the issued and
outstanding Equity Interests of Mediacom Capital, other than by reason of a
merger of Mediacom Capital into and with a corporate successor to Mediacom;
provided, however, that a Change of Control will be deemed not to have occurred
in any of the circumstances described in clauses (i) through (iv) above if after
the occurrence of any such circumstance (A) Rocco B. Commisso continues to be
the manager of Mediacom pursuant to the Operating Agreement and/or the chief
executive officer of Mediacom (or the surviving or transferee Person in the case
of clause (ii) above), or (B) Rocco B. Commisso and the other Permitted Holders
together with their respective designees constitute the majority of the members
of the Executive Committee.

          "Change of Control Offer" shall have the meaning ascribed thereto in
Section 1012.

                                       4
<PAGE>
 
          "Change of Control Payment" shall have the meaning ascribed thereto in
Section1012.

          "Code" means the Internal Revenue Code of 1986, as amended.

          "Committee Resolution" means with respect to Mediacom, a duly adopted
resolution of the Executive Committee of Mediacom.

          "Comparable Restriction Provisions" shall have the meaning ascribed
thereto in Section 1010.

          "Consolidated Income Tax Expense" means, with respect to Mediacom for
any period, the provision for federal, state, local and foreign income taxes
payable by Mediacom and the Restricted Subsidiaries for such period as
determined on a consolidated basis in accordance with generally accepted
accounting principles consistently applied.

          "Consolidated Interest Expense" means, with respect to Mediacom and
the Restricted Subsidiaries for any period, without duplication, the sum of (i)
the interest expense of Mediacom and the Restricted Subsidiaries for such period
as determined on a consolidated basis in accordance with generally accepted
accounting principles consistently applied, including, without limitation,
amortization of original issue discount on any Indebtedness and the interest
portion of any deferred payment obligation and after taking into account the
effect of elections made under any Hedging Agreements, however denominated, with
respect to such Indebtedness; (ii) the interest component of Capitalized Lease
Obligations paid, accrued and/or scheduled to be paid or accrued by Mediacom and
the Restricted Subsidiaries during such period as determined on a consolidated
basis in accordance with generally accepted accounting principles consistently
applied; and (iii) dividends and distributions in respect of Disqualified Equity
Interests actually paid in cash by Mediacom and the Restricted Subsidiaries
during such period as determined on a consolidated basis in accordance with
generally accepted accounting principles consistently applied. For purposes of
this definition, interest on a Capitalized Lease Obligation shall be deemed to
accrue at an interest rate reasonably determined by Mediacom to be the rate of
interest implicit in such Capitalized Lease Obligation in accordance with
generally accepted accounting principles consistently applied.

          "Consolidated Net Income" means, with respect to any period, the net
income (loss) of Mediacom and the Restricted Subsidiaries for such period
determined on a consolidated basis in accordance with generally accepted
accounting principles consistently applied, adjusted, to the extent included in
calculating such net income (loss), by excluding, without duplication, (i) all
extraordinary, unusual or nonrecurring items of income or expense and of gains
or losses and all gains and losses from the sale or other disposition of assets
out of the ordinary course of business (net of taxes, fees and expenses relating
to the transaction giving rise thereto) for such period; (ii) that portion of
such net income (loss) derived from or in respect of Investments in Persons
other than any Restricted Subsidiary, except to the extent actually received in
cash by Mediacom or any Restricted Subsidiary; (iii) the portion of such net
income (loss) allocable to minority interests in unconsolidated Persons for such
period, except to the extent actually received in cash by Mediacom or any
Restricted Subsidiary; (iv) net income (loss) of any other Person combined with
Mediacom or any Restricted Subsidiary on a "pooling of interests" basis
attributable to any period prior to the date of combination; (v) net income
(loss) of any Restricted Subsidiary to the extent that the declaration or
payment of dividends or similar distributions by that Restricted Subsidiary of
that net income (loss) is not at the date of determination permitted without any
prior governmental approval (which has not been obtained) or, directly or
indirectly, by operation of the terms of its charter or any agreement,
instrument, judgment, decree, order, statute, rule or governmental regulation
applicable to that Restricted Subsidiary or the holders of its Equity Interests;
(vi) the cumulative effect of a change in accounting principles after the date
of this Indenture; (vii) net income

                                       5
<PAGE>
 
(loss) attributable to discontinued operations; (viii) management fees payable
to the "manager" as defined in the Operating Agreement and to Mediacom
Management and its Affiliates pursuant to management agreements with
Subsidiaries of Mediacom accrued for such period that have not been paid during
such period; and (ix) any other item of expense, other than "interest expense,"
which appears on Mediacom's consolidated statement of income (loss) below the
line item "Operating Income," determined on a consolidated basis in accordance
with generally accepted accounting principles consistently applied.

          "Consolidated Total Indebtedness" means, as at any date of
determination, an amount equal to the aggregate amount of all outstanding
Indebtedness and the aggregate liquidation preference or redemption payment
value of all Disqualified Equity Interests of Mediacom and the Restricted
Subsidiaries outstanding as of such date of determination, less the obligations
of Mediacom or any Restricted Subsidiary under any Hedging Agreement as of such
date of determination that would appear as a liability on the balance sheet of
such Person, in each case determined on a consolidated basis in accordance with
generally accepted accounting principles consistently applied.

          "Continuing Member" means, as of the date of determination, any Person
who (i) was a member of the Executive Committee of Mediacom on the date of this
Indenture, (ii) was nominated for election or elected to the Executive Committee
of Mediacom with the affirmative vote of a majority of the Continuing Members
who were members of the Executive Committee at the time of such nomination or
election or (iii) is a representative of, or was approved by, a Permitted
Holder.

          "Controlled Subsidiary" means a Restricted Subsidiary which is engaged
in a Related Business (i) 80% or more of the outstanding Equity Interests of
which (other than Equity Interests constituting directors' qualifying shares to
the extent mandated by applicable law) are owned by Mediacom or by one or more
Wholly Owned Restricted Subsidiaries or Controlled Subsidiaries or by Mediacom
and one or more Wholly Owned Restricted Subsidiaries or Controlled Subsidiaries,
(ii) of which Mediacom possesses, directly or indirectly, the power to direct or
cause the direction of the management or policies, whether through the ownership
of Voting Equity Interests, by agreement or otherwise, and (iii) all of whose
Indebtedness is Non-Recourse Indebtedness.

          "Corporate Trust Office" means the office of the Trustee which
initially is located at 88 Pine Street, New York, New York.

          "Cumulative Credit" means the sum of (i) $10,000,000, plus (ii) the
aggregate Net Cash Proceeds received by Mediacom or a Restricted Subsidiary from
the issue or sale (other than to a Restricted Subsidiary) of Equity Interests of
Mediacom or a Restricted Subsidiary (other than Disqualified Equity Interests)
on or after April 1, 1998, plus (iii) the principal amount (or accreted amount
(determined in accordance with generally accepted accounting principles), if
less) of any Indebtedness, or the liquidation preference or redemption payment
value of any Disqualified Equity Interests, of Mediacom or any Restricted
Subsidiary which has been converted into or exchanged for Equity Interests of
Mediacom or a Restricted Subsidiary (other than Disqualified Equity Interests)
on or after April 1, 1998, plus (iv) cumulative Operating Cash Flow on or after
April 1, 1998, to the end of the fiscal quarter immediately preceding the date
of the proposed Restricted Payment, or, if cumulative Operating Cash Flow for
such period is negative, minus the amount by which cumulative Operating Cash
Flow is less than zero, plus (v) to the extent not already included in Operating
Cash Flow, if any Investment constituting a Restricted Payment that was made
after the date of this Indenture is sold or otherwise liquidated or repaid or
any Unrestricted Subsidiary which was designated as an Unrestricted Subsidiary
after the date of this Indenture is sold or otherwise liquidated, the fair
market value of such Restricted Payment (less the cost of disposition, if any)
on the date of such sale, liquidation or repayment, as determined in good faith
by the Executive Committee, whose determination shall be conclusive and
evidenced by a Committee Resolution, plus (vi) if any Unrestricted Subsidiary is
redesignated as a

                                       6
<PAGE>
 
Restricted Subsidiary, the value of the Restricted Payment that would result if
such Subsidiary were redesignated as an Unrestricted Subsidiary at such time,
determined in accordance with Section 1018.

          "Cumulative Interest Expense" means the aggregate amount of
Consolidated Interest Expense paid or accrued of the Issuers and the Restricted
Subsidiaries on or after April 1, 1998, to the end of the fiscal quarter
immediately preceding the proposed Restricted Payment.

          "Debt to Operating Cash Flow Ratio" means the ratio of (i) the
Consolidated Total Indebtedness as of the date of calculation (the
"Determination Date") to (ii) four times the Operating Cash Flow for the latest
three months for which financial information is available immediately preceding
such Determination Date (the "Measurement Period"). For purposes of calculating
Operating Cash Flow for the Measurement Period immediately prior to the relevant
Determination Date, (I) any Person that is a Restricted Subsidiary on the
Determination Date (or would become a Restricted Subsidiary on such
Determination Date in connection with the transaction that requires the
determination of such Operating Cash Flow) will be deemed to have been a
Restricted Subsidiary at all times during such Measurement Period; (II) any
Person that is not a Restricted Subsidiary on such Determination Date (or would
cease to be a Restricted Subsidiary on such Determination Date in connection
with the transaction that requires the determination of such Operating Cash
Flow) will be deemed not have been a Restricted Subsidiary at any time during
such Measurement Period; and (III) if Mediacom or any Restricted Subsidiary
shall have in any manner (x) acquired (including through an Asset Acquisition or
the commencement of activities constituting such operating business) or (y)
disposed of (including by way of an Asset Sale or the termination or
discontinuance of activities constituting such operating business) any operating
business during such Measurement Period or after the end of such period and on
or prior to such Determination Date, such calculation will be made on a pro
forma basis in accordance with generally accepted accounting principles
consistently applied, as if, in the case of an Asset Acquisition or the
commencement of activities constituting such operating business, all such
transactions had been consummated on the first day of such Measurement Period,
and, in the case of an Asset Sale or termination or discontinuance of activities
constituting such operating business, all such transactions had been consummated
prior to the first day of such Measurement Period.

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

          "Depositary" means The Depository Trust Company, its nominees and
their respective successors and assigns, or such other depository institution
hereinafter appointed by Mediacom.

          "Designation" shall have the meaning ascribed thereto in Section 1018.

          "Distribution Compliance Period" means the 40-day distribution
compliance period as defined in Regulation S under the Securities Act.

          "Disqualified Equity Interest" means (i) any Equity Interest issued by
Mediacom which, by its terms (or by the terms of any security into which it is
convertible or for which it is exchangeable at the option of the holder
thereof), or upon the happening of any event, matures or is mandatorily
redeemable, pursuant to a sinking fund obligation or otherwise, or is redeemable
at the option of the holder thereof (except, in each such case, upon the
occurrence of a Change of Control or a Regulatory Equity Interest Repurchase),
in whole or in part, or is exchangeable into Indebtedness, on or prior to the
earlier of the maturity date of the Notes or the date on which no Notes remain
outstanding; and (ii) any Equity Interest issued by any Restricted Subsidiary
which, by its terms (or by the terms of any security into which it is
convertible or for which it is exchangeable at the option of the holder
thereof), or upon the happening of any event, matures or is mandatorily
redeemable, pursuant to a sinking fund obligation or

                                       7
<PAGE>
 
otherwise, or is redeemable at the option of the holder thereof, in whole or in
part, or is exchangeable into Indebtedness.

          "Equity Interest" in any Person means any and all shares, interests,
rights to purchase, warrants, options, participations or other equivalents of or
interests in (however designated) corporate stock or other equity
participations, including partnership interests, whether general or limited, and
membership interests in such Person, including any Preferred Equity Interests.

          "Equity Offering" means a public or private offering by Mediacom or a
Restricted Subsidiary for cash of its respective Equity Interests (other than
Disqualified Equity Interests) or options, warrants or rights with respect to
such Equity Interests.

          "Excess Proceeds" means, with respect to any Asset Sale, the then
Available Asset Sale Proceeds less any such Available Asset Sale Proceeds that
are required to be applied and are applied in accordance with clause (iii)(b)(1)
of clause (a) of Section 1013.

          "Excess Proceeds Offer" shall have the meaning ascribed thereto in
Section 1013.

          "Exchange Act" means the Securities Exchange Act of 1934, as amended.

          "Exchange Offer" means the offer by the Issuers to exchange all of the
Initial Notes for a like aggregate principal amount of Exchange Notes, as
provided in the Registration Rights Agreement, and the offer by the Issuers to
exchange all of the Additional Notes for a like aggregate principal amount of
Exchange Notes, in each case as provided in this Indenture.

          "Exchange Offer Registration Statement" has the meaning ascribed
thereto in the Registration Rights Agreement.

          "Executive Committee" means (i) so long as Mediacom is a limited
liability company, (x) while the Operating Agreement is in effect, the Executive
Committee authorized thereunder, and (y) at any other time, the manager or board
of managers of Mediacom, or management committee or similar governing body
responsible for the management of the business and affairs of Mediacom; (ii) if
Mediacom were to be reorganized as a corporation, the board of directors of
Mediacom; and (iii) if Mediacom were to be reorganized as a partnership, the
board of directors of the corporate general partner of such partnership (or if
such general partner is itself a partnership, the board of directors of such
general partner's corporate general partner).

          "Future Subsidiary Credit Facilities" means one or more debt
facilities (other than the Subsidiary Credit Facilities) entered into from time
to time after the date of this Indenture by one or more Restricted Subsidiaries
or groups of Restricted Subsidiaries with banks or other institutional lenders,
together with all loan documents and instruments thereunder (including, without
limitation, any guarantee agreements and security documents), including any
amendment (including any amendment and restatement), modification or supplement
thereto or any refinancing, refunding, deferral, renewal, extension or
replacement thereof (including, in any such case and without limitation, adding
or removing Subsidiaries of Mediacom as borrowers or guarantors thereunder),
whether by the same or any other lender or group of lenders.

          "GAAP" or "generally accepted accounting principles" means generally
accepted accounting principles in the United States of America as in effect as
of the date of this Indenture, including those set forth in the opinions and
pronouncements of the Accounting Principles Board of the American Institute of
Certified Public Accountants and statements and pronouncements of the Financial

                                       8
<PAGE>
 
Accounting Standards Board or in such other statements by such other entity as
approved by a significant segment of the accounting profession. All ratios and
computations based on GAAP contained in this Indenture shall be computed in
conformity with GAAP.

          "Guarantor" means any Subsidiary of Mediacom that guarantees the
Issuers' obligations under this Indenture and the Notes issued after the date of
this Indenture pursuant to Section 1017.

          "Hedging Agreement" means any interest rate swap agreement, interest
rate cap agreement, interest rate collar agreement or other similar agreement
providing for the transfer or mitigation of interest rate risks either generally
or under specific contingencies.

          "Holder" or "Noteholder" means the Person in whose name a Note is
registered in the Note Register.

          "Incur" means, with respect to any Indebtedness or other obligation of
any Person, to create, issue, incur (including by conversion, exchange or
otherwise), assume, guarantee or otherwise become liable in respect of such
Indebtedness or other obligation or the recording, as required pursuant to
generally accepted accounting principles or otherwise, of any such Indebtedness
or other obligation on the balance sheet of such Person (and "Incurrence",
"Incurred" and "Incurring" shall have meanings correlative to the foregoing).
Indebtedness of any Person or any of its Subsidiaries existing at the time such
Person becomes a Restricted Subsidiary (or is merged into or consolidates with
Mediacom or any Restricted Subsidiary), whether or not such Indebtedness was
incurred in connection with, or in contemplation of, such Person becoming a
Restricted Subsidiary (or being merged into or consolidated with Mediacom or any
Restricted Subsidiary), shall be deemed Incurred at the time any such Person
becomes a Restricted Subsidiary or merges into or consolidates with Mediacom or
any Restricted Subsidiary.

          "Indebtedness" means, with respect to any Person, without duplication,
any indebtedness, secured or unsecured, contingent or otherwise, in respect of
borrowed money (whether or not the recourse of the lender is to the whole of the
assets of such Person or only to a portion thereof), or evidenced by bonds,
notes, debentures or similar instruments or letters of credit or representing
the deferred and unpaid balance of the purchase price of property or services
(but excluding trade payables incurred in the ordinary course of business and
non-interest bearing installment obligations and other accrued liabilities
arising in the ordinary course of business) if and to the extent any of the
foregoing indebtedness would appear as a liability upon a balance sheet of such
Person prepared in accordance with generally accepted accounting principles, and
shall also include, to the extent not otherwise included (but without
duplication), (i) any Capitalized Lease Obligations, (ii) obligations secured by
a lien to which any property or assets owned or held by such Person is subject,
whether or not the obligation or obligations secured thereby shall have been
assumed, (iii) guarantees of items of other Persons which would be included
within this definition for such other Persons (whether or not such items would
appear upon the balance sheet of the guarantor), and (iv) obligations of
Mediacom or any Restricted Subsidiary under any Hedging Agreement applicable to
any of the foregoing (if and only to the extent any amount due in respect of
such Hedging Agreement would appear as a liability upon a balance sheet of such
Person prepared in accordance with generally accepted accounting principles).
Indebtedness (i) shall not include obligations under performance bonds,
performance guarantees, surety bonds and appeal bonds, letters of credit or
similar obligations, Incurred in the ordinary course of business, including in
connection with pole rental or conduit attachments and the like or the
requirements of cable television franchising authorities, and otherwise
consistent with industry practice; (ii) shall not include obligations of any
Person (x) arising from the honoring by a bank or other financial institution of
a check, draft or other similar instrument inadvertently drawn against
insufficient funds in the ordinary course of business, provided such obligations
are extinguished within five business days of their Incurrence, (y) resulting

                                       9
<PAGE>
 
from the endorsement of negotiable instruments for collection in the ordinary
course of business and consistent with past practice and (z) under stand-by
letters of credit to the extent collateralized by cash or Cash Equivalents; and
(iii) which provides that an amount less than the principal amount thereof shall
be due upon any declaration of acceleration thereof shall be deemed to be
Incurred or outstanding in an amount equal to the accreted value thereof at the
date of determination.

          "Indenture" means this Indenture, as amended or supplemented from time
to time.

          "Investment" means, directly or indirectly, any advance, loan or other
extension of credit (including by means of a guarantee) or capital contribution
to (by means of transfers of property to others, payments for property or
services for the account or use of others or otherwise), the acquisition, by
purchase or otherwise, of any stock, bonds, notes, debentures, partnership,
membership or joint venture interests or other securities or other evidence of
beneficial interest of any Person, provided that the term "Investment" shall not
include any such advance, loan or extension of credit having a term not
exceeding 90 days arising in the ordinary course of business or any pledge of
Equity Interests pursuant to the Subsidiary Credit Facilities or any Future
Subsidiary Credit Facilities.  If Mediacom or any Restricted Subsidiary sells or
otherwise disposes of any Voting Equity Interest of any direct or indirect
Restricted Subsidiary such that, after giving effect to such sale or
disposition, Mediacom no longer owns, directly or indirectly, greater than 50%
of the outstanding Voting Equity Interests of such Restricted Subsidiary,
Mediacom shall be deemed to have made an Investment on the date of any such sale
or disposition equal to the fair market value of the Voting Equity Interests of
such former Restricted Subsidiary not sold or disposed of.

          "Issue Date" means the date on which the Initial Notes are originally
issued.

          "Issuers' Request" shall have the meaning ascribed thereto in Section
102.

          "Lien" means any mortgage, pledge, lien, charge, security interest,
hypothecation, assignment for security or encumbrance of any kind (including any
conditional sale or capital lease or other title retention agreement, any lease
in the nature thereof or any agreement to give a security interest).

          "Liquidated Damages" means the "liquidated damages" specified in
Section three of the Registration Rights Agreement or in such other registration
rights agreement to be executed in connection with the issuance of Additional
Notes.

          "Mediacom" means Mediacom LLC, a New York limited liability company.

          "Mediacom Arizona" means Mediacom Arizona LLC, a Delaware limited
liability company, and a wholly owned Subsidiary of Mediacom.

          "Mediacom California" means Mediacom California LLC, a Delaware
limited liability company, and a Subsidiary of Mediacom.

          "Mediacom Capital" means Mediacom Capital Corporation, a New York
corporation, and a wholly owned Subsidiary of Mediacom.

          "Mediacom Delaware" means Mediacom Delaware LLC, a Delaware limited
liability company, and a wholly owned Subsidiary of Mediacom.

                                       10
<PAGE>
 
          "Mediacom Management" means Mediacom Management Corporation, a
Delaware corporation.

          "Moody's" means Moody's Investors Service, Inc.

          "Net Cash Proceeds" means, with respect to any issuance or sale of
Equity Interests, the proceeds in the form of cash or Cash Equivalents received
by Mediacom or any Restricted Subsidiary of such issuance or sale net of
attorneys' fees, accountants fees, underwriters' or placement agents' fees,
discounts or commissions and brokerage, consultant and other fees actually
incurred in connection with such issuance or sale and net of taxes paid or
payable as a result thereof.

          "Non-Recourse Indebtedness" means Indebtedness of a Person (i) as to
which neither of the Issuers nor any of the Restricted Subsidiaries (other than
such Person or any Subsidiaries of such Person) (a) provides any guarantee or
credit support of any kind (including any undertaking, guarantee, indemnity,
agreement or instrument that would constitute Indebtedness) or (b) is directly
or indirectly liable (as a guarantor or otherwise); and (ii) the incurrence of
which will not result in any recourse against any of the assets of either of the
Issuers or the Restricted Subsidiaries (other than to such Person or to any
Subsidiaries of such Person and other than to the Equity Interests in such
Person or in another Restricted Subsidiary or an Unrestricted Subsidiary pledged
by Mediacom, a Restricted Subsidiary or an Unrestricted Subsidiary); provided,
however, that Mediacom or any Restricted Subsidiary may make a loan to a
Controlled Subsidiary or an Unrestricted Subsidiary, or guarantee a loan made to
a Controlled Subsidiary or an Unrestricted Subsidiary, if such loan or guarantee
is permitted under Section 1007 at the time of the making of such loan or
guarantee, and such loan or guarantee shall not constitute Indebtedness which is
not Non-Recourse Indebtedness.

          "Note Register" shall have the meaning ascribed thereto in Section
305.

          "Note Registrar" shall have the meaning ascribed thereto in Section
305.

          "Officer" means the Chairman, the Chief Executive Officer, any Senior
Vice President, the Treasurer or the Secretary of Mediacom.

          "Officers' Certificate" means a certificate signed by two Officers.

          "Operating Agreement" means the Third Amended and Restated Operating
Agreement of Mediacom dated as of January 20, 1998, as the same may be amended,
supplemented or modified from time to time.

          "Operating Cash Flow" means, with respect to Mediacom and the
Restricted Subsidiaries on a consolidated basis, for any period, an amount equal
to Consolidated Net Income for such period increased (without duplication) by
the sum of (i) Consolidated Income Tax Expense accrued for such period to the
extent deducted in determining Consolidated Net Income for such period; (ii)
Consolidated Interest Expense for such period to the extent deducted in
determining Consolidated Net Income for such period; and (iii) depreciation,
amortization and any other non-cash items for such period to the extent deducted
in determining Consolidated Net Income for such period (other than any non-cash
item (other than the management fees referred to in clause (viii) of the
definition of "Consolidated Net Income") which requires the accrual of, or a
reserve for, cash charges for any future period) of Mediacom and the Restricted
Subsidiaries, including, without limitation, amortization of capitalized debt
issuance costs for such period, all of the foregoing determined on a
consolidated basis in accordance with generally accepted accounting principles
consistently applied, and decreased by non-cash items to the extent they

                                       11
<PAGE>
 
increase Consolidated Net Income (including the partial or entire reversal of
reserves taken in prior periods) for such period.

          "Opinion of Counsel" means a written opinion from legal counsel who is
acceptable to the Trustee. The counsel may be an employee of or counsel to
Mediacom or the Trustee.

          "Other Pari Passu Debt" means Indebtedness of Mediacom or any
Restricted Subsidiary that does not constitute Subordinated Obligations that is
not senior in right of payment to the Notes.

          "Other Pari Passu Debt Pro Rata Share" means the amount of the
applicable Available Asset Sale Proceeds obtained by multiplying the amount of
such Available Asset Sale Proceeds by a fraction, (i) the numerator of which is
the aggregate principal amount and/or accreted value, as the case may be, of all
Other Pari Passu Debt outstanding at the time of the applicable Asset Sale with
respect to which Mediacom or any Restricted Subsidiary is required to use
Available Asset Sale Proceeds to repay or make an offer to purchase or repay and
(ii) the denominator of which is the sum of (a) the aggregate principal amount
of all Notes outstanding at the time of the applicable Asset Sale and (b) the
aggregate principal amount and/or accreted value, as the case may be, of all
Other Pari Passu Debt outstanding at the time of the applicable Asset Sale Offer
with respect to which Mediacom or any Restricted Subsidiary is required to use
the applicable Available Asset Sale Proceeds to offer to repay or make an offer
to purchase or repay.

          "Other Permitted Liens" means (i) Liens imposed by law, such as
carriers', warehousemen's and mechanics' liens and other similar liens arising
in the ordinary course of business which secure payment of obligations that are
not yet delinquent or that are being contested in good faith by appropriate
proceedings promptly instituted and diligently conducted and for which an
appropriate reserve or provision shall have been made in accordance with
generally accepted accounting principles consistently applied; (ii) Liens for
taxes, assessments or governmental charges or claims that are not yet delinquent
or that are being contested in good faith by appropriate proceedings promptly
instituted and diligently conducted and for which an appropriate reserve or
provision shall have been made in accordance with generally accepted accounting
principles consistently applied; (iii) easements, rights of way, and other
restrictions on use of property or minor imperfections of title that in the
aggregate are not material in amount and do not in any case materially detract
from the property subject thereto or interfere with the ordinary conduct of the
business of Mediacom or its Subsidiaries; (iv) Liens related to Capitalized
Lease Obligations, mortgage financings or purchase money obligations (including
refinancings thereof), in each case Incurred for the purpose of financing all or
any part of the purchase price or cost of construction or improvement of
property, plant or equipment used in the business of Mediacom or any Restricted
Subsidiary or a Related Business, provided that any such Lien encumbers only the
asset or assets so financed, purchased, constructed or improved; (v) Liens
resulting from the pledge by Mediacom of Equity Interests in a Restricted
Subsidiary in connection with a Subsidiary Credit Facility or a Future
Subsidiary Credit Facility or in an Unrestricted Subsidiary in any circumstance,
in each such case where recourse to Mediacom is limited to the value of the
Equity Interests so pledged; (vi) Liens resulting from the pledge by Mediacom of
intercompany indebtedness owed to Mediacom in connection with a Subsidiary
Credit Facility or a Future Subsidiary Credit Facility; (vii) Liens incurred or
deposits made in the ordinary course of business in connection with workers'
compensation, unemployment insurance and other types of social security; (viii)
Liens to secure the performance of statutory obligations, surety or appeal
bonds, performance bonds, deposits to secure the performance of bids, trade
contracts, government contracts, leases or licenses or other obligations of a
like nature incurred in the ordinary course of business (including without
limitation, landlord Liens on leased properties); (ix) leases or subleases
granted to third Persons not interfering with the ordinary course of business of
Mediacom; (x) deposits made in the ordinary course of business to secure
liability to insurance carriers; (xi) Liens securing reimbursement obligations
with respect to letters of credit which encumber documents

                                       12
<PAGE>
 
and other property relating to such letters of credit and the products and
proceeds thereof; (xii) Liens on the assets of Mediacom to secure hedging
agreements with respect to Indebtedness permitted by this Indenture to be
Incurred; (xiii) attachment or judgment Liens not giving rise to a Default or an
Event of Default; (xiv) any interest or title of a lessor under any capital
lease or operating lease; and (xv) Liens resulting from the pledge of "Unfunded
Capital Commitments" (as defined in the Operating Agreement) securing the
repayment of Indebtedness in respect of reimbursement obligations for letters of
credit given in connection with or in contemplation of the acquisition of a
Related Business.

          "Paying Agent" means an office or agency maintained by the Issuers
within the City and State of New York where Notes may be presented for payment.

          "Permitted Holder" means (i) Rocco B. Commisso or his spouse or
siblings, any of their lineal descendants and their spouses, (ii) any controlled
Affiliate of any individual described in clause (i) above, (iii) in the event of
the death or incompetence of any individual described in clause (i) above, such
Person's estate, executor, administrator, committee or other personal
representative, in each case who at any particular date will beneficially own or
have the right to acquire, directly or indirectly, Equity Interests of Mediacom,
(iv) any trust or trusts created for the benefit of each Person described in
this definition, including any trust for the benefit of the parents or siblings
of any individual described in clause (i) above, (v) any trust for the benefit
of any such trust, (vi) any of the holders of Equity Interests in Mediacom on
the date of this Indenture, or (vii) any of the Affiliates of any Person
described in clause (vi) above.

          "Permitted Investments" means (i) Cash Equivalents; (ii) Investments
in prepaid expenses, negotiable instruments held for collection and lease,
utility and workers' compensation, performance and other similar deposits; (iii)
the extension of credit to vendors, suppliers and customers in the ordinary
course of business; (iv) Investments existing as of the date of this Indenture,
and any amendment, modification, extension or renewal thereof to the extent such
amendment, modification, extension or renewal does not require Mediacom or any
Restricted Subsidiary to make any additional cash or non-cash payments or
provide additional services in connection therewith; (v) Hedging Agreements;
(vi) any Investment for which the sole consideration provided is Equity
Interests (other than Disqualified Equity Interests) of Mediacom; (vii) any
Investment consisting of a guarantee permitted under clause (e) of the second
paragraph of Section 1008; (viii) Investments in Mediacom, in any Wholly Owned
Restricted Subsidiary or in any Controlled Subsidiary or any Person that, as a
result of or in connection with such Investment, becomes a Wholly Owned
Restricted Subsidiary or a Controlled Subsidiary or is merged with or into or
consolidated with Mediacom or a Wholly Owned Restricted Subsidiary or a
Controlled Subsidiary; (ix) loans and advances to officers, directors and
employees of Mediacom and the Restricted Subsidiaries for business-related
travel expenses, moving expenses and other similar expenses in each case
incurred in the ordinary course of business; (x) any acquisition of assets
solely in exchange for the issuance of Equity Interests (other than Disqualified
Equity Interests) of Mediacom; (xi) Related Business Investments; and (xii)
other Investments made pursuant to this clause (xii) at any time, and from time
to time, after the date of this Indenture, in addition to any Permitted
Investments described in clauses (i) through (xi) above, in an aggregate amount
at any one time outstanding not to exceed $10,000,000.

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

          "Preferred Equity Interest" means, in any Person, an Equity Interest
of any class or classes, however designated, which is preferred as to the
payment of dividends or distributions, or as to

                                       13
<PAGE>
 
the distribution of assets upon any voluntary or involuntary liquidation or
dissolution of such Person, over Equity Interests of any other class in such
Person.

          "Private Exchange" means the issuance by the Issuers of a like amount
of Private Exchange Notes in exchange for Initial Notes or Additional Notes held
by a Holder which holds Initial Notes or Additional Notes acquired by it that
have, or that are reasonably likely to have, the status of an unsold allotment
in an initial distribution, or which is not entitled to participate in the
Exchange Offer, pursuant to the Registration Rights Agreement or similar
agreement with respect to the Additional Notes.

          "Private Exchange Notes" means the Issuers' 7 7/8% Senior Notes due
2011, if and when issued pursuant to a Private Exchange for Initial Notes or
Additional Notes.

          "Productive Assets" means assets of a kind used or useable by Mediacom
and the Restricted Subsidiaries in any Related Business and specifically
includes assets acquired through Asset Acquisitions (it being understood that
"assets" may include Equity Interests of a Person that owns such Productive
Assets, provided that after giving effect to such transaction, such Person would
be a Restricted Subsidiary).

          "QIB" shall have the meaning ascribed thereto under Rule 144A of the
Securities Act.

          "Redemption Date" shall have the meaning ascribed thereto in Section
1103.

          "Registration Rights Agreement" means the Exchange and Registration
Rights Agreement dated as of February 26, 1999 among Mediacom, Mediacom Capital
and Chase Securities Inc.

          "Regular Record Date" means, with respect to any Interest Payment
Date, the February 1 or August 1 (whether or not a Business Day), as the case
may be, next preceding such Interest Payment Date.

          "Regulatory Equity Interest Repurchase" shall have the meaning
ascribed thereto in Section 1007.

          "Reinvestment Date" shall have the meaning ascribed thereto in Section
1013.

          "Related Business" means a cable television, media and communications,
telecommunications or data transmission business, and businesses ancillary,
complementary or reasonably related thereto, and reasonable extensions thereof.

          "Related Business Investment" means (i) any capital expenditure or
Investment, in each case related to the business of Mediacom and its Restricted
Subsidiaries as conducted on the date of this Indenture and as such business may
thereafter evolve in the fields of Related Businesses, (ii) any Investment in
any other Person primarily engaged in a Related Business and (iii) any customary
deposits or earnest money payments made by Mediacom or any Restricted Subsidiary
in connection with or in contemplation of the acquisition of a Related Business.

          "Required Filing Dates" shall have the meaning ascribed thereto in
Section 1014.

          "Restricted Payment" means (i) any dividend (whether made in cash,
property or securities) on or with respect to any Equity Interests of Mediacom
or of any Restricted Subsidiary (other than with respect to Disqualified Equity
Interests and other than any dividend made to Mediacom or another Restricted
Subsidiary or any dividend payable in Equity Interests of Mediacom or any
Restricted

                                       14
<PAGE>
 
Subsidiary); or (ii) any distribution (whether made in cash, property or
securities) on or with respect to any Equity Interests of Mediacom or of any
Restricted Subsidiary (other than with respect to Disqualified Equity Interests
and other than any distribution made to Mediacom or another Restricted
Subsidiary or any distribution payable in Equity Interests of Mediacom or any
Restricted Subsidiary); or (iii) any redemption, repurchase, retirement or other
direct or indirect acquisition of any Equity Interests of Mediacom (other than
Disqualified Equity Interests), or any warrants, rights or options to purchase
or acquire any such Equity Interests or any securities exchangeable for or
convertible into any such Equity Interests; or (iv) any redemption, repurchase,
retirement or other direct or indirect acquisition for value or other payment of
principal, prior to any scheduled final maturity, scheduled repayment or
scheduled sinking fund payment, of any Subordinated Obligations; or (v) any
Investment (other than a Permitted Investment).

          "Restricted Subsidiary" means any Subsidiary of Mediacom that has not
been designated by the Executive Committee of Mediacom by a Committee Resolution
delivered to the Trustee as an Unrestricted Subsidiary pursuant to Section 1018.
Any such designation may be revoked by a Committee Resolution delivered to the
Trustee, subject to the provisions of such covenant.

          "Restricted Subsidiary Guarantee" shall have the meaning ascribed
thereto in Section 1017.

          "Revocation" shall have the meaning ascribed thereto in Section 1018.

          "S&P" means Standard & Poor's Ratings Group.

          "SEC" means the Securities and Exchange Commission.

          "Securities Act" means the Securities Act of 1933, as amended.

          "Shelf Registration Statement" has the meaning ascribed thereto in the
Registration Rights Agreement.

          "Significant Subsidiary" means any Restricted Subsidiary which at the
time of determination had (A) total assets which, as of the date of Mediacom's
most recent quarterly consolidated balance sheet, constituted at least 10% of
Mediacom's total assets on a consolidated basis as of such date, or (B) revenues
for the three-month period ending on the date of Mediacom's most recent
quarterly consolidated statement of income which constituted at least 10% of
Mediacom's total revenues on a consolidated basis for such period, or (C)
Subsidiary Operating Cash Flow for the three-month period ending on the date of
Mediacom's most recent quarterly consolidated statement of income which
constituted at least 10% of Mediacom's total Operating Cash Flow on a
consolidated basis for such period.

          "Southeast Credit Facility" means the $225,000,000 senior credit
facility dated as of January 23, 1998 among Mediacom Southeast, the lenders
party thereto and The Chase Manhattan Bank, as administrative agent, as amended
and restated through the date of this Indenture.

          "Specified Action" shall have the meaning ascribed thereto in Section
1010.

          "Specified Affilate Transaction" shall have the meaning ascribed
thereto in Section 1009.

                                       15
<PAGE>
 
          "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.

          "Subordinated Obligations" means, with respect to either of the
Issuers, any Indebtedness of either of the Issuers which is expressly
subordinated in right of payment to the Notes.

          "Subsidiary" means a Person the majority of whose voting stock,
membership interests or other Voting Equity Interests is or are owned by
Mediacom or a Subsidiary.  Voting stock in a corporation is Equity Interests
having voting power under ordinary circumstances to elect directors.

          "Subsidiary Credit Facilities" means the Southeast Credit Facility and
the Western Credit Facility, together with all loan documents and instruments
thereunder (including, without limitation, any guarantee agreements and security
documents), including any amendment (including any amendment and restatement),
modification or supplement thereto or any refinancing, refunding, deferral,
renewal, extension or replacement thereof (including, in any such case and
without limitation, adding or removing Subsidiaries of Mediacom as borrowers or
guarantors thereunder), whether by the same or any other lender or group of
lenders, pursuant to which (i) an aggregate amount of Indebtedness up to
$325,000,000 may be Incurred pursuant to clause (c)(i) of the second paragraph
of Section 1008 and (ii) any additional amount of Indebtedness in excess of
$325,000,000 may be Incurred pursuant to the first paragraph or pursuant to
clause (c)(ii) or any other applicable clause (other than clause (c)(i)) of the
second paragraph of Section 1008.

          "Subsidiary Operating Cash Flow" means, with respect to any Subsidiary
for any period, the "Operating Cash Flow" of such Subsidiary and its
Subsidiaries for such period determined by utilizing all of the elements of the
definition of "Operating Cash Flow" in this Indenture, including the defined
terms used in such definition, consistently applied only to such Subsidiary and
its Subsidiaries on a consolidated basis for such period.

          "Successor Company" shall have the meaning ascribed thereto in Section
801.

          "TIA" means the Trust Indenture Act of 1939 (15 U.S.C. (S)(S) 77aaa-
77bbbb) as in effect on the date of this Indenture.

          "Trust Officer" means an officer of the Trustee assigned by the
Trustee to administer its corporate trust matters or to any other officer of the
Trustee to whom such matter is referred because of his knowledge of and
familiarity with the particular subject.

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

          "Unrestricted Subsidiary" means any Subsidiary of Mediacom designated
as such pursuant to the provisions of Section 1018, and any Subsidiary of an
Unrestricted Subsidiary. Any such designation may be revoked by a Committee
Resolution delivered to the Trustee, subject to the provisions of such covenant.

          "U.S. Government Obligations" means direct obligations (or
certificates representing an ownership interest in such obligations) of the
United States of America (including any agency or instrumentality thereof) for
the payment of which the full faith and credit of the United States of America
is pledged and which are not callable or redeemable at the issuer's option.

                                       16
<PAGE>
 
          "Voting Equity Interests" means Equity Interests in any Person with
voting power under ordinary circumstances entitling the holders thereof to elect
the Executive Committee, the board of managers, board of directors or other
governing body of such Person.

          "Weighted Average Life to Maturity" means, when applied to any
Indebtedness at any date, the number of years obtained by dividing (i) the sum
of the products obtained by multiplying (a) the amount of each then remaining
installment, sinking fund, serial maturity or other required scheduled payment
of principal, including payment of final maturity, in respect thereof by (b) the
number of years (calculated to the nearest one-twelfth) that will elapse between
such date and the making of such payment, by (ii) the then outstanding aggregate
principal amount of such Indebtedness.

          "Western Credit Facility" means the $100,000,000 senior credit
facility dated as of June 24, 1997 among Mediacom California, Mediacom Arizona
and Mediacom Delaware, the lenders party thereto, and The Chase Manhattan Bank,
as administrative agent, as amended and restated through the date of this
Indenture.

          "Wholly Owned Restricted Subsidiary" means a Restricted Subsidiary 99%
or more of the outstanding Equity Interests of which (other than Equity
Interests constituting directors' qualifying shares to the extent mandated by
applicable law) are owned by Mediacom or by one or more Wholly Owned Restricted
Subsidiaries or by Mediacom and one or more Wholly Owned Restricted
Subsidiaries.

          SECTION 102.  Compliance Certificates and Opinions.
                        ------------------------------------ 

          Upon any application or request by the Issuers (an "Issuers' Request")
to the Trustee to take any action under any provision of this Indenture, the
Issuers and any other obligor on the Notes shall furnish to the Trustee an
Officers' Certificate in form and substance reasonably acceptable to the Trustee
stating that all conditions precedent, if any, provided for in this Indenture
(including any covenant compliance with which constitutes a condition precedent)
relating to the proposed action have been complied with and an Opinion of
Counsel stating that in the opinion of such counsel all such conditions
precedent, if any, have been complied with, except that in the case of any such
application or request as to which the furnishing of such documents is
specifically required by any provision of this Indenture relating to such
particular application or request, no additional certificate or opinion need be
furnished.

          Each certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (including certificates
provided pursuant to Section 1016(a)) shall include:

          (1) a statement that each individual signing such certificate or
     opinion has read such covenant or condition and the definitions herein
     relating thereto;

          (2) 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;

          (3) a statement that, in the opinion of each such individual or such
     firm, he or it has made such examination or investigation as is necessary
     to enable him or it to express an informed opinion as to whether or not
     such covenant or condition has been complied with; and

          (4) a statement as to whether, in the opinion of each such individual,
     such condition or covenant has been complied with.

                                       17
<PAGE>
 
          SECTION 103.  Form of Documents Delivered to Trustee.
                        -------------------------------------- 

          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.

          Any certificate or opinion of an officer of the Issuers or any other
obligor on the Notes may be based, insofar as it relates to legal matters, upon
a certificate or opinion of, or representations by, counsel, unless such officer
knows, or in the exercise of reasonable care should know, that the certificate
or opinion or representations with respect to the matters upon which his
certificate or opinion is based are erroneous. Any such certificate or Opinion
of Counsel may be based, insofar as it relates to factual matters, upon a
certificate or opinion of, or representations by, an officer or officers of the
Issuers or any other obligor on the Notes stating that the information with
respect to such factual matters is in the possession of the Issuers or any other
obligor on the Notes unless such counsel knows, or in the exercise of reasonable
care should know, that the certificate or opinion or representations with
respect to such matters are erroneous.

          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 104.  Acts of Holders.
                        --------------- 

          (i)   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 agents duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required, to the Issuers. 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 conclusive in favor of the Trustee and the Issuers, if made in the
manner provided in this Section 104.

          (ii)  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 a certificate 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 his individual
capacity, such certificate or affidavit shall also constitute sufficient proof
of 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 that the Trustee deems sufficient.

          (iii) The principal amount and serial numbers of Notes held by any
Person, and the date of holding the same, shall be proved by the Note Register.

          (iv)  If the Issuers shall solicit from the Holders any request,
demand, authorization, direction, notice, consent, waiver or other Act, the
Issuers may, at their option, by or pursuant to a

                                       18
<PAGE>
 
Committee Resolution, fix in advance a record date for the determination of
Holders entitled to give such request, demand, authorization, direction, notice,
consent, waiver or other Act, but the Issuers shall have no obligation to do so.
Notwithstanding TIA (S) 316(c), such record date shall be the record date
specified in or pursuant to such Committee Resolution, which shall be a date not
earlier than the date 30 days prior to the first solicitation of Holders
generally in connection therewith and not later than the date such solicitation
is completed. If such a record date is fixed, such request, demand,
authorization, direction, notice, consent, waiver or other Act may be given
before or after such record date, but only the Holders of record at the close of
business on such record date shall be deemed to be Holders for the purposes of
determining whether Holders of the requisite proportion of outstanding Notes
have authorized or agreed or consented to such request, demand, authorization,
direction, notice, consent, waiver or other Act, and for that purpose the
outstanding Notes shall be computed as of such record date; provided that no
such authorization, agreement or consent by the Holders on such record date
shall be deemed effective unless it shall become effective pursuant to the
provisions of this Indenture not later than six months after the record date.

          (v)   Any request, demand, authorization, direction, notice, consent,
waiver or other Act of the Holder of any Note shall bind every future Holder of
the same Note and the Holder of every Note issued upon the registration of
transfer thereof or in exchange therefor or in lieu thereof (including in
accordance with Section 310) in respect of anything done, omitted or suffered to
be done by the Trustee, any Paying Agent or the Issuers in reliance thereon,
whether or not notation of such action is made upon such Note.

          SECTION 105.  Notices, Etc., to Trustee and the Issuers.
                        ----------------------------------------- 

          Any request, demand, authorization, direction, notice, consent, waiver
or Act of Holders or other document provided or permitted by this Indenture to
be made upon, given or furnished to, or filed with,

          (1) the Trustee by any Holder or by the Issuers or any other obligor
     on the Notes shall be sufficient for every purpose hereunder if made,
     given, furnished or delivered in writing and mailed, first-class postage
     prepaid, or delivered by recognized overnight courier, to or with the
     Trustee and received at its Corporate Trust Office, Attention: Corporate
     Trust Administration, or

          (2) the Issuers by the Trustee or by any Holder shall be sufficient
     for every purpose hereunder (unless otherwise herein expressly provided) if
     made, given, furnished or delivered, in writing, or mailed, first-class
     postage prepaid, or delivered by recognized overnight courier, to the
     Issuers addressed to it and received at the address of its principal office
     specified in the first paragraph of this Indenture, or at any other address
     previously furnished in writing to the Trustee by the Issuers.

          SECTION 106.  Notice to Holders; Waiver.
                        ------------------------- 

          Where this Indenture provides for notice of any event to Holders by
the Issuers or the Trustee, such notice shall be sufficiently given (unless
otherwise herein expressly provided) if in writing and mailed, first-class
postage prepaid, to each Holder, at his address as it appears in the Note
Register, not later than the latest date, and not earlier than the earliest
date, prescribed for the giving of such notice. Neither the failure to mail such
notice, nor any defect in any notice so mailed, to any particular Holder shall
affect the sufficiency of such notice with respect to other Holders. Any notice
mailed to a Holder in the manner herein prescribed shall be conclusively deemed
to have been received by such Holder, whether or not such Holder actually
receives such notice. Where this Indenture provides for notice in any manner,
such notice may be waived in writing by the Person entitled to receive such
notice, either before 

                                       19
<PAGE>
 
or after the event, and such waiver shall be the equivalent of such notice.
Waivers of notice by Holders shall be filed with the Trustee, but such filing
shall not be a condition precedent to the validity of any action taken in
reliance upon such waiver.

          In case by reason of the suspension of or irregularities in regular
mail service or by reason of any other cause, it shall be impracticable to mail
notice of any event to Holders when such notice is required to be given pursuant
to any provision of this Indenture, then any manner of giving such notice as
shall be satisfactory to the Trustee shall be deemed to be a sufficient giving
of such notice for every purpose hereunder.

          If the Issuers mail any notice or communication to any Holder, they
shall mail a copy to the Trustee at the same time.

          SECTION 107.  Effect of Headings and Table of Contents.
                        ---------------------------------------- 

          The Article and Section headings herein and the Table of Contents are
for convenience only and shall not affect the construction hereof.

          SECTION 108.  Successors and Assigns.
                        ---------------------- 

          All covenants and agreements in this Indenture by the Issuers shall
bind each of their successors and assigns, whether so expressed or not.

          SECTION 109.  Separability Clause.
                        ------------------- 

          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 110.  Benefits of Indenture.
                        --------------------- 

          Nothing in this Indenture or in the Notes, express or implied, shall
give to any Person, (other than the parties hereto, any agent and their
successors hereunder and each of the Holders) any benefit or any legal or
equitable right, remedy or claim under this Indenture.

          SECTION 111.  Governing Law.
                        ------------- 

          THIS INDENTURE AND THE NOTES SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK EXCLUDING (TO THE GREATEST
EXTENT PERMISSIBLE BY LAW) ANY RULE OF LAW THAT WOULD CAUSE THE APPLICATION OF
THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF NEW YORK. UPON THE ISSUANCE
OF THE EXCHANGE NOTES OR THE EFFECTIVENESS OF THE SHELF REGISTRATION STATEMENT,
THIS INDENTURE SHALL BE SUBJECT TO THE PROVISIONS OF THE TRUST INDENTURE ACT
THAT ARE REQUIRED TO BE PART OF THIS INDENTURE AND SHALL, TO THE EXTENT
APPLICABLE, BE GOVERNED BY SUCH PROVISIONS. EACH OF THE PARTIES HERETO AGREES TO
SUBMIT TO THE JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK AND THE U.S.
FEDERAL COURTS, IN EACH CASE SITTING IN THE BOROUGH OF MANHATTAN, AND WAIVES ANY
OBJECTION AS TO VENUE OR FORUM NON CONVENIENS.

                                       20
<PAGE>
 
          SECTION 112.  Legal Holidays.
                        -------------- 

          In any case where any interest payment date, any date established for
payment of Defaulted Interest pursuant to Section 311 or redemption date or
Stated Maturity of any Note shall not be a Business Day, then (notwithstanding
any other provision of this Indenture or of the Notes) payment of principal (or
premium, if any) or interest need not be made on such date, but may be made on
the next succeeding Business Day with the same force and effect as if made on
the interest payment date or date established for payment of Defaulted Interest
pursuant to Section 311, Redemption Date, or at the Stated Maturity or maturity;
provided that no interest shall accrue for the period from and after such
interest payment date, redemption date or date established for payment of
Defaulted Interest pursuant to Section 311, Stated Maturity or maturity, as the
case may be, to the next succeeding Business Day.

          SECTION 113.  No Personal Liability of Directors, Officers, Employees,
                        --------------------------------------------------------
Stockholders or Incorporators.
----------------------------- 

          No manager, director, officer, employee, member, shareholder, partner
or incorporator of either Issuer or any Subsidiary, as such, shall have any
liability for any obligations of the Issuers under the Notes, this Indenture or
for any claim based on, in respect of, or by reason of, such obligations or
their creation. Each Holder by accepting a Note waives and releases all such
liability. Such waiver and release are part of the consideration for the
issuance of the Notes.

          SECTION 114.  Counterparts.
                        ------------ 

          This Indenture may be signed in any number of counterparts each of
which so executed shall be deemed to be an original, but all such counterparts
shall together constitute but one and the same Indenture.

          SECTION 115.  Communications by Holders with Other Holders.
                        -------------------------------------------- 

          Holders may communicate pursuant to TIA (S) 312(b) with other Holders
with respect to their rights under this Indenture or the Notes. The Issuers, the
Trustee, the Note Registrar and anyone else shall have the protection of TIA (S)
312(c).


                                  ARTICLE TWO.
                                   NOTE FORMS

          SECTION 201.  Forms Generally.
                        --------------- 

          The Notes and the Trustee's certificate of authentication shall be in
substantially the forms set forth in this Article, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Indenture, and may have such letters, numbers or other marks
of identification and such legends or endorsements placed thereon as may be
required to comply with applicable laws or the rules of any securities exchange
or Depositary or as may, consistently herewith, be determined by the officers
executing such Notes, as evidenced by their execution of the Notes. Any portion
of the text of any Note may be set forth on the reverse thereof, with an
appropriate reference thereto on the face of the Note. Each Note shall be dated
the date of its authentication.

          Initial Notes offered and sold to qualified institutional buyers (as
defined in Rule 144A under the Securities Act) in the United States of America
("Rule 144A Note") shall be issued on the Issue

                                       21
<PAGE>
 
Date, and Additional Notes offered and sold to qualified institutional buyers in
the United States of America shall be issued, in the form of a permanent global
Note, without interest coupons, substantially in the form set forth in Sections
203 and 204 (the "Rule 144A Global Note") deposited with the Trustee, as
custodian for the Depositary, duly executed by the Issuers and authenticated by
the Trustee as hereinafter provided. The Rule 144A Global Note may be
represented by more than one certificate, if so required by the Depositary's
rules regarding the maximum principal amount to be represented by a single
certificate. The aggregate principal amount of the Rule 144A Global Note may
from time to time be increased or decreased by adjustments made on the records
of the Trustee, as custodian for the Depositary or its nominee, as hereinafter
provided.

          Initial Notes offered and sold in offshore transactions to Non-U.S.
Persons ("Regulation S Note") in reliance on Regulation S shall be issued on the
Issue Date, and Additional Notes offered and sold in offshore transactions to
Non-U.S. Persons in reliance on Regulation S shall be issued, in the form of a
global Note, without interest coupons, substantially in the form set forth in
Sections 203 and 204 (the "Regulation S Global Note").  The Regulation S Global
Note will be deposited with the Trustee, as custodian for the Depositary, duly
executed by the Issuers and authenticated by the Trustee as hereinafter
provided. The Regulation S Global Note may be represented by more than one
certificate, if so required by the Depositary's rules regarding the maximum
principal amount to be represented by a single certificate. The aggregate
principal amount of the Regulation S Global Note may from time to time be
increased or decreased by adjustments made on the records of the Trustee, as
custodian for the Depositary or its nominee, as hereinafter provided.

          Initial Notes offered and sold to institutional "accredited investors"
(as defined in Rule 501(a)(1), (2), (3) and (7) under the Securities Act) in the
United States of America ("Institutional Accredited Investor Note") shall be
issued, and Additional Notes offered and sold to institutional accredited
investors in the United States of America shall be issued, in the form of a
permanent global Note substantially in the form set forth in Sections 203 and
204 (a "Institutional Accredited Investor Global Note") deposited with the
Trustee, as custodian for the Depositary, duly executed by the Issuers and
authenticated by the Trustee as hereinafter provided. The Institutional
Accredited Investor Global Note may be represented by more than one certificate,
if so required by the Depositary's rules regarding the maximum principal amount
to be represented by a single certificate. The aggregate principal amount of the
Institutional Accredited Investor Global Note may from time to time be increased
or decreased by adjustments made on the records of the Trustee, as custodian for
the Depositary or its nominee, as hereinafter provided.

          The Rule 144A Global Note, the Regulation S Global Note and the
Institutional Accredited Investor Global Note are sometimes collectively herein
referred to as the "Global Notes."

          The definitive Notes shall be printed, lithographed or engraved on
steel-engraved borders or may be produced in any other manner, all as determined
by the officers of the Issuers executing such Notes, as evidenced by their
execution of such Notes.

          SECTION 202.  Restrictive Legends.
                        ------------------- 

          Unless and until (i) an Initial Note or Additional Note is sold under
an effective Registration Statement or (ii) an Initial Note or Additional Note
is exchanged for an Exchange Note in connection with an effective Registration
Statement, in each case pursuant to the Registration Rights Agreement, such Rule
144A Global Note and the Institutional Accredited Investor Global Note shall
bear the following legend (the "Private Placement Legend") on the face thereof:

                                       22
<PAGE>
 
          THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
     1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS.
     NEITHER THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE
     REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE
     DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION
     IS EXEMPT FROM, OR NOT SUBJECT TO, REGISTRATION.

          THE HOLDER OF THIS SECURITY BY ITS ACCEPTANCE HEREOF AGREES TO OFFER,
     SELL OR OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE "RESALE
     RESTRICTION TERMINATION DATE") WHICH IS TWO YEARS AFTER THE LATER OF THE
     ORIGINAL ISSUE DATE HEREOF AND THE LAST DATE ON WHICH THE ISSUERS OR ANY
     AFFILIATE OF THE ISSUERS WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR
     OF SUCH SECURITY), ONLY (A) TO THE ISSUERS, (B) PURSUANT TO A REGISTRATION
     STATEMENT THAT HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES ACT, (C)
     FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A
     UNDER THE SECURITIES ACT ("RULE 144A"), TO A PERSON IT REASONABLY BELIEVES
     IS A "QUALIFIED INSTITUTIONAL BUYER" AS DEFINED IN RULE 144A THAT PURCHASES
     FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER
     TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE
     144A, (D) PURSUANT TO OFFERS AND SALES THAT OCCUR OUTSIDE THE UNITED STATES
     WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT, (E) TO AN
     INSTITUTIONAL "ACCREDITED INVESTOR" WITHIN THE MEANING OF SECTION
     501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT THAT IS ACQUIRING THE
     SECURITY FOR ITS OWN ACCOUNT, OR FOR THE ACCOUNT OF SUCH AN INSTITUTIONAL
     ACCREDITED INVESTOR, IN EACH CASE IN A MINIMUM PRINCIPAL AMOUNT OF $250,000
     OF SUCH SECURITIES, FOR INVESTMENT PURPOSES AND NOT WITH A VIEW TO OR FOR
     OFFER OR SALE IN CONNECTION WITH ANY DISTRIBUTION IN VIOLATION OF THE
     SECURITIES ACT, OR (F) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE
     REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO THE ISSUERS'
     AND THE TRUSTEE'S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER PURSUANT
     TO CLAUSE (D), (E) OR (F) ABOVE TO REQUIRE THE DELIVERY OF AN OPINION OF
     COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO EACH OF
     THEM, AND IN THE CASE OF ANY OF THE FOREGOING CLAUSES (A) THROUGH (F), A
     CERTIFICATE OF TRANSFER IN THE FORM APPEARING ON THE OTHER SIDE OF THIS
     SECURITY IS COMPLETED AND DELIVERED BY THE TRANSFEROR TO THE ISSUERS AND
     THE TRUSTEE. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF THE HOLDER
     AFTER THE RESALE RESTRICTION TERMINATION DATE.

          The Regulation S Global Note shall bear the following legend on the
     face thereof:

          THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE UNITED STATES
     SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND,
     ACCORDINGLY, MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED

                                       23
<PAGE>
 
     STATES OR TO OR FOR THE ACCOUNT OR BENEFIT OF, U.S. PERSONS EXCEPT AS SET
     FORTH IN THE FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF, THE HOLDER (1)
     REPRESENTS THAT IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS SECURITY IN
     AN OFFSHORE TRANSACTION, (2) BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL
     OR OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE "RESALE
     RESTRICTION TERMINATION DATE") WHICH IS TWO YEARS AFTER THE LATER OF THE
     ORIGINAL ISSUE DATE HEREOF AND THE LAST DATE ON WHICH THE ISSUERS OR ANY
     AFFILIATE OF THE ISSUERS WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR
     OF SUCH SECURITY), ONLY (A) TO THE ISSUERS, (B) PURSUANT TO A REGISTRATION
     STATEMENT THAT HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES ACT, (C)
     FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A
     UNDER THE SECURITIES ACT, TO A PERSON IT REASONABLY BELIEVES IS A
     "QUALIFIED INSTITUTIONAL BUYER" AS DEFINED IN RULE 144A THAT PURCHASES FOR
     ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO
     WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE
     144A, (D) PURSUANT TO OFFERS AND SALES THAT OCCUR OUTSIDE THE UNITED STATES
     WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT, (E) TO AN
     INSTITUTIONAL "ACCREDITED INVESTOR" WITHIN THE MEANING OF SECTION
     501(A)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT THAT IS ACQUIRING THE
     SECURITY FOR ITS OWN ACCOUNT, OR FOR THE ACCOUNT OF SUCH AN INSTITUTIONAL
     "ACCREDITED INVESTOR", IN EACH CASE IN A MINIMUM PRINCIPAL AMOUNT OF
     $250,000 OF SUCH SECURITIES, FOR INVESTMENT PURPOSES AND NOT WITH A VIEW TO
     OR FOR OFFER OR SALE IN CONNECTION WITH ANY DISTRIBUTION IN VIOLATION OF
     THE SECURITIES ACT, OR (F) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE
     REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO THE ISSUERS'
     AND THE TRUSTEE'S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER PURSUANT
     TO CLAUSE (D), (E) OR (F) ABOVE TO REQUIRE THE DELIVERY OF AN OPINION OF
     COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO EACH OF
     THEM, AND IN THE CASE ANY OF THE FOREGOING CLAUSES (A) THROUGH (F), A
     CERTIFICATE OF TRANSFER IN THE FORM APPEARING ON THE OTHER SIDE OF THIS
     SECURITY IS COMPLETED AND DELIVERED BY THE TRANSFEROR TO THE ISSUERS AND
     THE TRUSTEE. THIS LEGEND WILL BE REMOVED AFTER 40 CONSECUTIVE DAYS
     BEGINNING ON AND INCLUDING THE LATER OF (A) THE DAY ON WHICH THE SECURITIES
     ARE OFFERED TO PERSONS OTHER THAN DISTRIBUTORS (AS DEFINED IN REGULATION S)
     AND (B) THE DATE OF THE CLOSING OF THE ORIGINAL OFFERING. AS USED HEREIN,
     THE TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE
     THE MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT.

                                       24
<PAGE>
 
          The Global Notes, whether or not an Initial Note or Additional Note,
shall also bear the following legend on the face thereof:

          UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
     OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
     ISSUERS OR THEIR 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 IN AS MUCH AS
     THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

          TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS IN
     WHOLE, BUT NOT IN PART, TO NOMINEES OF CEDE & CO. OR TO A SUCCESSOR THEREOF
     OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
     SECURITY SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
     RESTRICTIONS SET FORTH IN SECTIONS 306 AND 307 OF THE INDENTURE.

                                       25
<PAGE>
 
          SECTION 203.  Form of Note.
                        ------------ 

                         7 7/8% Senior Notes due 2011

No. ___                         Principal Amount at Maturity $__________________
                                                             CUSIP NO.__________

     Mediacom LLC, a New York limited liability company, and Mediacom Capital
Corporation, a New York corporation, as joint and several obligors promise to
pay to ______________, or registered assigns, the principal sum of ____________
Dollars on February 15, 2011.

     Interest Payment Dates:  February 15 and August  15

     Record Dates:    February 1 and August 1

     This Note shall bear interest from February 26, 1999 through February 15,
2011.

     Additional provisions of this Note are set forth on the other side of this
Note.

                                       26
<PAGE>
 
     IN WITNESS WHEREOF, the Issuers have caused this Note to be signed manually
or by facsimile by its authorized Officers.

Dated: ________, ____



                                 MEDIACOM LLC



                                 By:
                                    --------------------------------
                                    Name:
                                    Title:



                                 By:
                                    --------------------------------
                                    Name:
                                    Title:



                                 MEDIACOM CAPITAL CORPORATION



                                 By:
                                    --------------------------------
                                    Name:
                                    Title:



                                 By:
                                    --------------------------------
                                    Name:
                                    Title:

                                       27
<PAGE>
 
                    TRUSTEE'S CERTIFICATE OF AUTHENTICATION


     This is one of the Notes referred to in the within-mentioned Indenture.


                                 BANK OF MONTREAL TRUST COMPANY,
                                 as Trustee


                                 By:
                                    --------------------------------
                                    Authorized Signature

                                       28
<PAGE>
 
                     [FORM OF REVERSE SIDE OF SENIOR NOTE]

                         7 7/8% Senior Notes due 2011

1.   Interest
     --------

     Mediacom LLC, a New York limited liability company, and Mediacom Capital
Corporation, a New York corporation (such entities, and their successors and
assigns under the Indenture hereinafter referred to, being herein called the
"Issuers"), jointly and severally promise to pay interest on the principal
amount of this Note as described below.

     Interest on the Senior Notes due 2011 (the "Notes") will accrue at a rate
of 7 7/8% per annum, payable semiannually, to Holders of record on each February
1 or August 1 immediately preceding the interest payment date on February 15 and
August 15 of each year, commencing August 15, 1999. Interest will be computed on
the basis of a 360-day year comprised of twelve 30-day months.

2.   Method of Payment
     -----------------

     By at least 10:00 a.m. (New York City time) on the date on which any
principal of or interest on the Notes is due and payable, the Issuers shall
irrevocably deposit with the Trustee or the Paying Agent money sufficient to pay
such principal, premium, if any, and/or interest.  The Issuers will pay interest
(except defaulted interest) to the Persons who are registered Holders of Notes
at the close of business on the February 1 or August 1 next preceding the
interest payment date even if the Notes are cancelled, repurchased or redeemed
after the record date and on or before the interest payment date. Holders must
surrender Notes to a Paying Agent to collect principal payments.  The Issuers
will pay principal and interest in money of the United States that at the time
of payment is legal tender for payment of public and private debts. However, the
Issuers may pay interest by check payable in such money. The Issuers may mail an
interest check to a Holder's registered address; provided that all payments with
respect to global Notes and certificated Notes the Holders of which have given
written wire transfer instructions to the Trustee by no later than five business
days prior to the relevant payment date shall be required to be made by wire
transfer of immediately available funds to the accounts specified by the Holders
thereof.

3.   Trustee, Paying Agent and Registrar
     -----------------------------------

     Initially, Bank of Montreal Trust Company, a New York trust company
("Trustee"), will act as Trustee, Paying Agent and Note Registrar. The Issuers
may appoint and change any Paying Agent, Note Registrar or co-registrar without
notice to any Noteholder.

4.   Indenture
     ---------

     The Issuers issued the Notes under an Indenture dated as of February 26,
1999 (as it may be amended or supplemented from time to time in accordance with
the terms thereof, the "Indenture"), among the Issuers and the Trustee. The
terms of the Notes include those stated in the Indenture and those made part of
the Indenture by reference to the Trust Indenture Act of 1939 (15 U.S.C. (S)(S)
77aaa-77bbbb) (the "TIA"). Capitalized terms used herein and not defined herein
have the meanings ascribed thereto in the Indenture. The Notes are subject to
all such terms, and Noteholders are referred to the Indenture and the TIA for a
statement of those terms.

     The Notes are unsecured senior obligations of the Issuers limited to
$125,000,000 aggregate principal amount at maturity, except for Notes
authenticated and delivered upon registration of transfer of,

                                       29
<PAGE>
 
or in exchange for, or in lieu of, other Notes pursuant to Section 304, 305,
306, 307, 310, 906, 1012, 1013 or 1108 or pursuant to an Exchange Offer or
Private Exchange Offer, and, subject to compliance with the covenants contained
in this Indenture, including Section 1008 as a new Incurrence of Indebtedness by
the Issuers, up to $250,000,000 aggregate principal amount of Additional Notes
having substantially identical terms and conditions as the Initial Notes. This
Note is one of the [Initial]/1/ Notes referred to in the Indenture. The Notes
include the Notes and any Exchange Notes or Private Exchange Notes issued in
exchange for the Initial Notes or Additional Notes pursuant to the Indenture.
The Initial Notes, the Additional Notes, the Exchange Notes and the Private
Exchange Notes are treated as a single class of securities under the Indenture.
The Indenture imposes certain limitations on the Incurrence of Indebtedness by
the Issuers, and the Issuers' Restricted Subsidiaries, the payment of dividends
on, and the purchase or redemption of Equity Interests of Mediacom and its
Restricted Subsidiaries, the sale or transfer of assets, investments of Mediacom
and its Restricted Subsidiaries and transactions with Affiliates. In addition,
the Indenture limits the ability of Mediacom and its Restricted Subsidiaries to
restrict distributions and dividends from Restricted Subsidiaries.

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

     Except as set forth below, the Notes are not redeemable prior to February
15, 2006. Thereafter, the Notes will be redeemable, in whole or in part, from
time to time at the option of the Issuers, on not less than 30 and not more than
60 days' notice prior to the redemption date by first class mail to each holder
of Notes to be redeemed at such holder's address appearing in the Note Register
maintained by the Note Registrar at the following redemption prices (expressed
as percentages of principal amount) if redeemed during the twelve-month period
beginning with February 15 in the year indicated below, in each case together
with accrued and unpaid interest and Liquidated Damages, if any, thereon to the
date of redemption:

<TABLE>
<CAPTION>
Period                                          Redemption Price
------                                          ----------------
<S>                                             <C>
2006.................................               103.938%
2007.................................               101.969%
2008 and thereafter..................               100.000%
</TABLE>

     In addition, at any time and from time to time, on or prior to February 15,
2002, the Issuers may redeem up to 35% of the original principal amount of Notes
(calculated to give effect to any issuance of Additional Notes) with the Net
Cash Proceeds of one or more Equity Offerings of Mediacom, at a redemption price
in cash equal to 107.875% of the principal to be redeemed plus accrued and
unpaid interest and Liquidated Damages, if any, to the date of redemption;
provided that at least 65% of the original principal amount of the Notes (as so
calculated) remains outstanding after each such redemption.  Any such redemption
will be required to occur within 90 days following the closing of any such
Equity Offering.

6.   Selection
     ---------

     If fewer than all the Notes are to be redeemed, the Trustee will select the
Notes to be redeemed, if the Notes are listed on a national securities exchange,
in accordance with the rules of such exchange or, if the Notes are not so
listed, on a pro rata basis or by lot or by such other method that the Trustee
deems to be fair and equitable to holders. If any Note is to be redeemed in part
only, the notice of redemption that relates to such Note shall state the portion
of the principal amount thereof to be redeemed and a new Note

-----------------------
/1/ Include only for the Initial Notes or Additional Notes.

                                       30
<PAGE>
 
or Notes in principal amount equal to the unredeemed principal portion thereof
will be issued; provided, that no Notes of a principal amount of $1,000 or less
shall be redeemed in part. On and after the redemption date, interest will cease
to accrue on Notes or portions thereof called for redemption as long as the
Issuers have deposited with the Paying Agent for the Notes funds in satisfaction
of the applicable redemption price pursuant to the Indenture.

7.   Change of Control
     -----------------

     Upon the occurrence of a Change Control, each holder of Notes shall have
the right to require the Issuers to repurchase all or any part of such Holder's
Notes pursuant to a Change of Control Offer at a purchase price equal to 101% of
the principal amount thereof plus accrued and unpaid interest and Liquidated
Damages, if any, to the date of purchase (subject to the right of holders of
record on the relevant record date to receive interest due on the relevant
interest payment date).

8.   Denominations; Transfer; Exchange
     ---------------------------------

     The Notes are in registered form without coupons in denominations of
principal amount of $1,000 and whole multiples of $1,000. A Holder may transfer
or exchange Notes in accordance with the Indenture. The Note Registrar may
require a Holder, among other things, to furnish appropriate endorsements or
transfer documents and to pay any taxes and fees required by law or permitted by
the Indenture. The Note Registrar need not register the transfer of or exchange
of (i) any Note selected for redemption (except, in the case of a Note to be
redeemed in part, the portion of the Note not to be redeemed) for a period
beginning 15 days before a selection of Notes to be redeemed and ending on the
date of such selection or (ii) any Notes for a period beginning 15 days before
an interest payment date and ending on such interest payment date.

9.   Persons Deemed Owners
     ---------------------

     The registered holder of this Note may be treated as the owner of it for
all purposes.

10.  Unclaimed Money
     ---------------

     If money for the payment of principal or interest remains unclaimed for two
years, the Trustee or Paying Agent shall pay the money back to the Issuers at
their request unless an abandoned property law designates another Person. After
any such payment, Holders entitled to the money must look only to the Issuers
and not to the Trustee for payment.

11.  Defeasance
     ----------

     Subject to certain conditions set forth in the Indenture, the Issuers at
any time may terminate some or all of their obligations under the Notes and the
Indenture if the Issuers deposit with the Trustee money or U.S. Government
Obligations for the payment of principal and interest on the Notes to redemption
or maturity, as the case may be.  The Issuers in their sole discretion can
defease the Notes.

12.  Amendment, Waiver
     -----------------

     Subject to certain exceptions set forth in the Indenture, (i) the
Indenture, the Notes or the Restricted Subsidiary Guarantees may be amended with
the written consent of the Holders of at least a majority in aggregate principal
amount of the then outstanding Notes and (ii) any default or noncompliance with
any provision may be waived with the consent of the Holders of a majority in
principal amount of the outstanding Notes. Without the consent of any
Noteholder, the Issuers and the

                                       31
<PAGE>
 
Trustee may amend the Indenture or the Notes to cure any ambiguity, omission,
defect or inconsistency, or to comply with Article 8 of the Indenture, or to
provide for uncertificated Notes in addition to or in place of certificated
Notes or to add guarantees with respect to the Notes or to secure the Notes, or
to add additional covenants or surrender rights and powers conferred on the
Issuers, or to comply with any request of the SEC in connection with qualifying
the Indenture under the Act, or to make any change that does not adversely
affect the rights of any Noteholder.

13.  Defaults and Remedies
     ---------------------

     Under the Indenture, Events of Default include (i) a default in the payment
of principal of, or premium, if any, on the Notes when due at their Stated
Maturity, upon optional redemption, upon required repurchase, upon declaration
or otherwise, (ii) a default in any payment of interest or Liquidated Damages,
if any, on the Notes when due, continued for 30 days, (iii) the failure by
either of the Issuers or the Guarantors to comply for 60 days after written
notice by holders of not less than 25% in principal amount of the Notes then
outstanding with any other covenant, representation, warranty or other agreement
contained in the Indenture or the Notes, (iv) default in the payment at maturity
(continued for the longer of any applicable grace period or 30 days) of any
Indebtedness aggregating $15,000,000 or more of the Issuers or any Significant
Subsidiary or any group of Restricted Subsidiaries of Mediacom which, if merged
into each other, would constitute a Significant Subsidiary, or the acceleration
of any such Indebtedness which default shall not be cured or waived, or such
acceleration shall not be rescinded or annulled, within 30 days after written
notice by the holders of not less than 25% in principal amount of the Notes then
outstanding or (v) any final judgment or judgments for the payment of money in
excess of $15,000,000 (net of amounts covered by insurance) is rendered against
the Issuers or a Significant Subsidiary or any group of Restricted Subsidiaries
of Mediacom, which, if merged into each other, would constitute a Significant
Subsidiary, and such judgment or judgments remain undischarged for any period of
60 consecutive days, during which a stay of enforcement of such judgment shall
not be in effect.  Certain events of bankruptcy or insolvency are Events of
Default which will result in the Notes being due and payable immediately upon
the occurrence of such Events of Default.  The failure by any Restricted
Subsidiary Guarantee to be in full force and effect (except as contemplated by
the terms thereof) or any Guarantor to deny or disaffirm its obligations under
the Indenture or any Restricted Subsidiary Guarantee shall also be an Event of
Default.

     If an Event of Default occurs and is continuing (other than an Event of
Default resulting from certain events of bankruptcy, insolvency or
reorganization), the Trustee or the Holders of not less than 25% in principal
amount of the outstanding Notes may declare the principal of and accrued and
unpaid interest, if any, on all the Notes to be due and payable immediately.
Upon such a declaration, such principal and accrued and unpaid interest shall be
due and payable immediately. Under certain circumstances, the holders of a
majority in principal amount of the outstanding Notes may rescind any such
acceleration with respect to the Notes and its consequences.  Notwithstanding
the foregoing, in the case of an Event of Default resulting from certain events
of bankruptcy, insolvency or reorganization, all outstanding Notes shall be due
and payable immediately without further action or notice.

     Noteholders may not enforce the Indenture or the Notes except as provided
in the Indenture. The Trustee may refuse to enforce the Indenture or the Notes
unless it receives reasonable indemnity or security. Subject to certain
limitations, Holders of a majority in principal amount of the Notes may direct
the Trustee in its exercise of any trust or power. The Trustee may withhold from
Noteholders notice of any continuing Default or Event of Default (except a
Default or Event of Default in payment of principal interest) if it determines
that withholding notice is in their interest.

                                       32
<PAGE>
 
14.  Trustee Dealings with the Issuers
     ---------------------------------

     Subject to certain limitations set forth in the Indenture, the Trustee
under the Indenture, in its individual or any other capacity, may become the
owner or pledgee of Notes and may otherwise deal with and collect obligations
owed to it by the Issuers or their affiliates and may otherwise deal with the
Issuers or their affiliates with the same rights it would have if it were not
Trustee.

15.  No Recourse Against Others
     --------------------------

     A manager, director, officer, employee, member, shareholder, partner or
incorporator of either Issuer or any Subsidiary, as such, shall not have any
liability for any obligations of the Issuers under the Notes or the Indenture or
for any claim based on, in respect of or by reason of, such obligations or their
creation. By accepting a Note, each Noteholder waives and releases all such
liability.

16.  Authentication
     --------------

     This Note shall not be valid until an authorized signatory of the Trustee
(or an authenticating agent acting on its behalf) manually signs the certificate
of authentication on the other side of this Note.

[17.  Registration Rights
      -------------------

     The Holder of this Initial Note is entitled to the benefits of the Exchange
and Registration Rights Agreement, dated as of February 26, 1999 (the
"Registration Rights Agreement"), among the Issuers and the initial purchaser
named therein.]/2/

18.  Abbreviations
     -------------

     Customary abbreviations may be used in the name of a Noteholder or an
assignee, such as TEN COM (=tenants in common), TEN ENT (=tenants by the
entirety), JT TEN (=joint tenants with rights of survivorship and not as tenants
in common), CUST (=custodian) and U/G/M/A (=Uniform Gift to Minors Act).

19.  CUSIP Numbers
     -------------

     Pursuant to a recommendation promulgated by the Committee on Uniform
Security Identification Procedures, the Issuers have caused CUSIP numbers to be
printed on the Notes and have directed the Trustee to use CUSIP numbers in
notices of redemption as a convenience to Noteholders. No representation is made
as to the accuracy of such numbers either as printed on the Notes or as
contained in any notice of redemption and reliance may be placed only on the
other identification numbers placed thereon.

20.  Governing Law
     -------------

     THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS
OF THE STATE OF NEW YORK EXCLUDING (TO THE GREATEST EXTENT PERMISSIBLE BY LAW)
ANY RULE OF LAW THAT WOULD CAUSE THE APPLICATION OF THE LAWS OF ANY JURISDICTION
OTHER THAN THE STATE OF NEW YORK.

----------------------
/2/  Include only for the Initial Notes.

                                       33
<PAGE>
 
21.  Restricted Subsidiary Guarantees.
     -------------------------------- 

     This Note may after the date hereof be entitled to certain Restricted
Subsidiary Guarantees made for the benefit of the Holders.  Reference is hereby
made to the Indenture for the terms of any Restricted Subsidiary Guarantee.

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


     Mediacom LLC
     100 Crystal Run Road
     Middletown, New York 10941
     Attention:  Rocco B. Commisso

                                       34
<PAGE>
 
                                ASSIGNMENT FORM

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 the Issuers.
The agent may substitute another to act for him.

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

Date: ______________________  Your Signature: ________________________________

Signature Guarantee: ________________________________________________________

     (Signature must be guaranteed)

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

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

The signature(s) should be guaranteed by an eligible guarantor institution
(banks, stockbrokers, savings and loan associations and credit unions with
membership in the Securities Transfer Agents Medallion Program ("STAMP") or such
other signature guarantee medallion program as may be approved by the Note
Registrar in addition to or substitution for, STAMP), pursuant to SEC Rule 17Ad-
15.

[In connection with any transfer or exchange of any of the Notes evidenced by
this certificate occurring prior to the date that is two years 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 the Issuers or any Affiliate of the Issuers, the
undersigned confirms that such Notes are being:

CHECK ONE BOX BELOW:

     1[ ]  acquired for the undersigned's own account, without transfer; or

     2[ ]  transferred to the Issuers; or

     3[ ]  transferred pursuant to and in compliance with Rule 144A under the
           Securities Act of 1933; or

     4[ ]  transferred pursuant to an effective registration statement under the
           Securities Act of 1933; or

     5[ ]  transferred pursuant to and in compliance with Regulation S under the
           Securities Act of 1933; or

                                       35
<PAGE>
 
     6[ ]  transferred to an institutional "accredited investor" (as defined in
           Rule 501 (a)(1), (2), (3) or (7) under the Securities Act of 1933),
           that has furnished to the Trustee a signed letter containing certain
           representations and agreements (the form of which letter appears as
           Section 308 of the Indenture); or

     7[ ]  transferred pursuant to another available exemption from the
           registration requirements of the Securities Act of 1933.

Unless one of the boxes is checked, the Trustee may 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 (5), (6) or (7) is
checked, the Trustee or the Issuers may require, prior to registering any such
transfer of the Notes, in their sole discretion, such legal opinions,
certifications and other information as the Trustee or the Issuers may
reasonably request 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 of 1933, such as the exemption provided by
Rule 144 under such Act.


                                                _____________________________
                                                           Signature

Signature Guarantee:

_______________________________

(Signature must be guaranteed)

_______________________________

Signature


The signature(s) should be guaranteed by an eligible guarantor institution
(banks, stockbrokers, savings and loan associations and credit unions) with
membership in the Securities Transfer Agents Medallion Program ("STAMP") or such
other signature guarantee medallion program as may be approved by the Note
Registrar in addition to or substitution for STAMP, pursuant to SEC Rule 17Ad-
15.]/3/

--------------------------
/3/  Include only for the Initial Notes, Additional Notes and Private Exchange
     Notes.

                                       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 Global  Signature of authorized
Date of   Amount of decrease in Principal  Amount of increase in Principal  Note following such decrease     signatory of Trustee or
Exchange  Amount of this Global Note       Amount of this Global Note       or increase                      Notes custodian
--------  -------------------------------  -------------------------------  -------------------------------  -----------------------


</TABLE>

                                       37
<PAGE>
 
                       OPTION OF HOLDER TO ELECT PURCHASE

          If you want to elect to have this Note purchased by the Issuers
pursuant to Section 1012 or 1013 of the Indenture, check the box:

                                      [ ]

          If you want to elect to have only part of this Note purchased by the
Issuers pursuant to Section 1012 or 1013 of the Indenture, state the amount in
principal amount (must be integral multiple of $1,000):  $_______________.


Date:  ___________________  Your Signature ____________________________________
                                            (Sign exactly as your name appears
                                               on the other side of the Note)

Signature Guarantee: ______________________________________
                       (Signature must be guaranteed)

The signature(s) should be guaranteed by an eligible guarantor institution
(banks, stockbrokers, savings and loan associations and credit unions) with
membership in the Securities Transfer Agents Medallion Program ("STAMP") or such
other signature guarantee medallion program as may be approved by the Note
Registrar in addition to or substitution for STAMP, pursuant to SEC Rule 17Ad-
15.

                                       38
<PAGE>
 
          SECTION 204.   Form of Trustee's Certificate of Authentication.
                         ----------------------------------------------- 

          The Trustee's certificate of authentication shall be in substantially
          the following form:


                    TRUSTEE'S CERTIFICATE OF AUTHENTICATION.

          This is one of the Notes referred to in the within-mentioned
Indenture.

                              Bank of Montreal Trust Company, as Trustee


                              By_______________________
                                    Authorized Signature

                                       39
<PAGE>
 
                                 ARTICLE THREE.

                                   THE NOTES

          SECTION 301.  Title and Terms.
                        --------------- 

          The aggregate principal amount of Notes which may be authenticated and
delivered under this Indenture is limited to $125,000,000 aggregate principal
amount at maturity of Initial Notes, except for Notes authenticated and
delivered upon registration of transfer of, or in exchange for, or in lieu of,
other Notes pursuant to Section 304, 305, 306, 307, 310, 906, 1012, 1013 or
1108, pursuant to an Exchange Offer or pursuant to a Private Exchange Offer,
and, subject to compliance with the covenants contained in this Indenture,
including Section 1008 as a new Incurrence of Indebtedness by the Issuers, up to
$250,000,000 aggregate principal amount of additional Notes (the "Additional
Notes") having substantially identical terms and conditions to the Initial
Notes.  Any Additional Notes shall constitute part of the same issue as the
Initial Notes offered on the date of this Indenture.

          The Initial Notes and the Additional Notes shall be known and
designated as the "7 7/8% Senior Notes due 2011," and the Exchange Notes shall
be known and designated as the "7 7/8% Senior Notes due 2011," in each case, of
the Issuers. The Notes will initially be issued in an aggregate principal amount
of $125,000,000 with a Stated Maturity of February 15, 2011. Interest on the
Notes will accrue at a rate per annum of 7 7/8% and will be payable semiannually
in cash and in arrears to the Holders of record on each February 1 or August 1
immediately preceding the interest payment date on February 15 and August 15 of
each year, commencing August 15, 1999. Interest on the Notes will accrue from
the most recent interest payment date to which interest has been paid or, if no
interest has been paid, from February 26, 1999. All references to the principal
amount of the Notes herein are references to the principal amount at final
maturity. Interest will be computed on the basis of a 360-day year comprised of
twelve 30-day months, until the principal thereof is paid or duly provided for
Interest on any overdue principal, interest (to the extent lawful) or premium,
if any, shall be payable on demand.

          The principal of (and premium, if any) and interest on the Notes shall
be payable at the office or agency of the Issuers maintained for such purpose in
the Borough of Manhattan, The City of New York, or at such other office or
agency of the Issuers as may be maintained for such purpose; provided, however,
that, at the option of the Issuers, interest may be paid by check mailed to
addresses of the Persons entitled thereto as such addresses shall appear on the
Note Register.

          Holders shall have the right to require the Issuers to purchase their
Notes, in whole or in part, in the event of a Change of Control pursuant to
Section 1012.

          The Notes shall be subject to repurchase by the Issuers pursuant to an
Excess Proceeds Offer as provided in Section 1013.

          The Notes shall be redeemable as provided in Article Eleven and in the
Notes.

          SECTION 302.  Denominations.
                        ------------- 

          The Notes shall be issuable only in fully registered form, without
coupons, and only in denominations of $1,000 and any integral multiple thereof.

                                       40
<PAGE>
 
          SECTION 303.  Execution, Authentication, Delivery and Dating.
                        ---------------------------------------------- 

          The Notes shall be executed by each of the Issuers by two Officers.
The signature of any Officer on the Notes may be manual or facsimile signatures
of the present or any future such authorized officer and may be imprinted or
otherwise reproduced on the Notes.

          Notes bearing the manual or facsimile signatures of individuals who
were at any time the proper officers of the Issuers shall bind the Issuers,
notwithstanding that such individuals or any of them have ceased to hold such
offices prior to the authentication and delivery of such Notes or did not hold
such offices at the date of such Notes.

          At any time and from time to time after the execution and delivery of
this Indenture, the Issuers may deliver Initial Notes or Additional Notes
executed by the Issuers to the Trustee for authentication, together with an
order for the authentication and delivery of such Notes (the "Authentication
Order"), and the Trustee in accordance with such Authentication Order shall
authenticate and deliver such Initial Notes or Additional Notes directing the
Trustee to authenticate the Notes and certifying that all conditions precedent
to the issuance of Notes contained herein have been fully complied with, and the
Trustee in accordance with such Authentication Order shall authenticate and
deliver such Initial Notes or Additional Notes. Upon receipt of the
Authentication Order, the Trustee shall authenticate for original issue Exchange
Notes and Private Exchange Notes; provided that such Exchange Notes and Private
Exchange Notes shall be issuable only upon the valid surrender for cancellation
of Initial Notes or Additional Notes of a like aggregate principal amount.  The
Trustee shall be entitled to receive an Officers' Certificate and an Opinion of
Counsel of the Issuers that it may reasonably request in connection with such
authentication of Notes.  Such order shall specify the amount of Notes to be
authenticated and the date on which the original issue of Initial Notes,
Additional Notes, Exchange Notes or Private Exchange Notes is to be
authenticated.

          Each Note shall be dated the date of its authentication.

          No Note shall be entitled to any benefit under this Indenture or be
valid or obligatory for any purpose unless there appears on such Note a
certificate of authentication substantially in the form provided for herein duly
executed by the Trustee by manual signature of an authorized signatory, and such
certificate upon any Note shall be conclusive evidence, and the only evidence,
that such Note has been duly authenticated and delivered hereunder and is
entitled to the benefits of this Indenture.

          In case either of the Issuers, pursuant to Article Eight, shall be
consolidated or merged with or into any other Person or shall convey, transfer,
lease or otherwise dispose of substantially all of its assets to any Person, and
the successor Person resulting from such consolidation, or surviving such
merger, or into which such Issuer shall have been merged, or the Person which
shall have received a conveyance, transfer, lease or other disposition as
aforesaid, shall have executed an indenture supplemental hereto with the Trustee
pursuant to Article Eight, any of the Notes authenticated or delivered prior to
such consolidation, merger, conveyance, transfer, lease or other disposition
may, from time to time, at the request of the successor Person, be exchanged for
other Notes executed in the name of the successor Person with such changes in
phraseology and form as may be appropriate, but otherwise in substance of like
tenor as the Notes surrendered for such exchange and of like principal amount;
and the Trustee, upon the Issuers' Request of the successor Person, shall
authenticate and deliver Notes as specified in such request for the purpose of
such exchange. If Notes shall at any time be authenticated and delivered in any
new name of a successor Person pursuant to this Section 303 in exchange or
substitution for or upon registration of transfer of any Notes, such successor
Person, at the option of the Holders but without expense to them, shall provide
for the exchange of all Notes at the time outstanding for Notes authenticated
and delivered in such new name.

                                       41
<PAGE>
 
          The Trustee may appoint an authenticating agent acceptable to the
Issuers to authenticate Notes on behalf of the Trustee. 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. An
authenticating agent has the same rights as any Note Registrar or Paying Agent
to deal with the Issuers and their Affiliates hereunder.

          SECTION 304.  Temporary Notes.
                        --------------- 

          Pending the preparation of definitive Notes, the Issuers may execute,
and upon Authentication Order the Trustee shall authenticate and deliver,
temporary Notes which are printed, lithographed, typewritten, mimeographed or
otherwise produced, in any authorized denomination. Temporary Notes shall be
substantially of the tenor of the definitive Notes in lieu of which they are
issued and with such appropriate insertions, omissions, substitutions and other
variations as the officers executing such Notes may determine, as conclusively
evidenced by their execution of such Notes.

          If temporary Notes are issued, the Issuers will 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 at the office or agency of the Issuers
designated for such purpose pursuant to Section 1002, without charge to the
Holder. Upon surrender for cancellation of any one or more temporary Notes, the
Issuers shall execute and the Trustee shall authenticate and deliver in exchange
therefor a like principal amount of definitive Notes of authorized
denominations. Until so exchanged, the temporary Notes shall in all respects be
entitled to the same benefits under this Indenture as definitive Notes.

          SECTION 305.  Registration, Registration of Transfer and Exchange.
                        --------------------------------------------------- 

          The Issuers shall cause to be kept at the Corporate Trust Office a
register (the register maintained in such office and in any other office or
agency designated pursuant to Section 1002 being herein sometimes referred to as
the "Note Register") in which, subject to such reasonable regulations as it may
prescribe, the Issuers shall provide for the registration of Notes and of
transfers of Notes. The Note Register shall be in written form or any other form
capable of being converted into written form within a reasonable time. At all
reasonable times, the Note Register shall be open to inspection by the Trustee.
The Trustee is hereby initially appointed as security registrar (the Trustee in
such capacity, together with any successor of the Trustee in such capacity, the
"Note Registrar") for the purpose of registering Notes and transfers of Notes as
herein provided.

          Upon surrender for registration of transfer of any Note at the office
or agency of the Issuers designated pursuant to Section 1002, the Issuers shall
execute, and the Trustee shall authenticate and deliver, in the name of the
designated transferee or transferees, one or more new Notes of any authorized
denomination or denominations of a like aggregate principal amount.

          Furthermore, any Holder of a Global Note shall, by acceptance of such
Global Note, agree that transfers of beneficial interest in such Global Note may
be effected only through a book-entry system maintained by the Holder of such
Global Note (or its agent), and that ownership of a beneficial interest in the
Note shall be required to be reflected in a book entry.

          At the option of the Holder, Notes may be exchanged for other Notes of
any authorized denomination (not less than $1,000) and of a like aggregate
principal amount, upon surrender of the Notes to be exchanged at such office or
agency. Whenever any Notes are so surrendered for exchange (including an
exchange of Initial Notes or Additional Notes for Exchange Notes or Private
Exchange Notes), the Issuers shall execute, and the Trustee shall authenticate
and deliver, the Notes which the

                                       42
<PAGE>
 
Holder making the exchange is entitled to receive; provided that (i) no exchange
of Initial Notes for Exchange Notes shall occur until an Exchange Offer
Registration Statement shall have been declared effective by the SEC, the
Trustee shall have received an Officers' Certificate confirming that the
Exchange Offer Registration Statement has been declared effective by the SEC and
the Initial Notes to be exchanged for the Exchange Notes shall be cancelled by
the Trustee and (ii) no exchange of Additional Notes for Exchange Notes shall
occur until a registration statement shall have been declared effective by the
SEC, the Trustee shall have received an Officers' Certificate confirming that
the registration statement has been declared effective by the SEC and the
Additional Notes to be exchanged for the Exchange Notes shall be cancelled by
the Trustee.

          All Notes issued upon any registration of transfer or exchange of
Notes shall be the valid obligations of the Issuers, evidencing the same debt,
and entitled to the same benefits under this Indenture, as the Notes surrendered
upon such registration of transfer or exchange.

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

          No service charge shall be made for any registration of transfer or
exchange or redemption of Notes, but the Issuers 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 Section 304, 906, 1012, or 1108, not involving any
transfer.

          The Note Register shall be in written form in the English language or
in any other form including computerized records, capable of being converted
into such form within a reasonable time.

          SECTION 306.  Book-Entry Provisions for Global Notes.
                        -------------------------------------- 

          (a) Each Global Note initially shall (i) be registered in the name of
the Depositary for such global Note or the nominee of such Depositary, (ii) be
delivered to the Trustee as custodian for such Depositary and (iii) bear legends
as set forth in Section 202.

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

          (b) Transfers of a Global Note shall be limited to transfers of such
Global Note in whole, but not in part, to the Depositary, its successors or
their respective nominees.  Interests of beneficial owners in a Global Note may
be transferred in accordance with the rules and procedures of the Depositary and
the provisions of Section 307.  If required to do so pursuant to any applicable
law or regulation, beneficial owners may obtain Notes in definitive form
("Certificated Notes") in exchange for their beneficial interests in a Global
Note upon written request in accordance with the Depositary's and the Note
Registrar's procedures. In addition, Certificated Notes shall be transferred to
all beneficial owners in exchange for their beneficial interests in a Global
Note if (i) the Depositary notifies the Issuers

                                       43
<PAGE>
 
that it is unwilling or unable to continue as Depositary for such Global Note or
the Depositary ceases to be a clearing agency registered under the Exchange Act,
at a time when the Depositary is required to be so registered in order to act as
Depositary, and in each case a successor depositary is not appointed by the
Issuers within 90 days of such notice or, (ii) the Issuers execute and deliver
to the Trustee and Note Registrar an Officers' Certificate stating that such
Global Note shall be so exchangeable or (iii) an Event of Default has occurred
and is continuing and the Note Registrar has received a request from the
Depositary.

          (c) In connection with any transfer of a portion of the beneficial
interest in a Global Note pursuant to subsection (b) of this Section to
beneficial owners who are required to hold Certificated Notes, the Note
Registrar shall reflect on its books and records the date and a decrease in the
principal amount of such Global Note in an amount equal to the principal amount
of the beneficial interest in the Global Note to be transferred, and the Issuers
shall execute, and the Trustee shall authenticate and deliver, one or more
Certificated Notes of like tenor and amount.

          (d) In connection with the transfer of an entire Global Note to
beneficial owners pursuant to subsection (b) of this Section, such Global Note
shall be deemed to be surrendered to the Trustee for cancellation, and the
Issuers shall execute, and the Trustee shall authenticate and deliver, to each
beneficial owner identified by the Depositary in exchange for its beneficial
interest in such Global Note, an equal aggregate principal amount of
Certificated Notes of authorized denominations.

          (e) Any Certificated Note delivered in exchange for an interest in a
Global Note pursuant to subsection (c) or subsection (d) of this Section shall,
except as otherwise provided by paragraph (c) of Section 307, bear the
applicable legend regarding transfer restrictions applicable to the Certificated
Note set forth in Section 202.

          (f) The registered holder of a Global Note may grant proxies and
otherwise authorize any person, including Agent Members and persons that may
hold interests through Agent Members, to take any action which a Holder is
entitled to take under this Indenture or the Notes.

          SECTION 307.  Special Transfer Provisions.
                        --------------------------- 

          (a) The following provisions shall apply with respect to any proposed
transfer of a Rule 144A Note or an Institutional Accredited Investor Note prior
to the expiration of the Resale Restriction Termination Date (as defined in
Section 202):

          (i) a transfer of a Rule 144A Note or an Institutional Accredited
     Investor Note or a beneficial interest therein to a QIB (as defined herein)
     shall be made upon the representation of the transferee that it is
     purchasing the 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 and acknowledges that it has received such information
     regarding the Issuers as the undersigned has requested pursuant to Rule
     144A or has determined not to request such information and that it is aware
     that the transferor is relying upon its foregoing representations in order
     to claim the exemption from registration provided by Rule 144A;

          (ii) a transfer of a Rule 144A Note or an Institutional Accredited
     Investor Note or a beneficial interest therein to an institutional
     accredited investor shall be made upon receipt by the Trustee or its agent
     of a certificate substantially in the form set forth in Section 308 from
     the

                                       44
<PAGE>
 
     proposed transferee and, if requested by the Issuers or the Trustee, the
     delivery of an opinion of counsel, certification and/or other information
     satisfactory to each of them; and

          (iii)  a transfer of a Rule 144A Note or an Institutional Accredited
     Investor Note or a beneficial interest therein to a Non-U.S. Person shall
     be made upon receipt by the Trustee or its agent of a certificate
     substantially in the form set forth in Section 309 from the transferor and,
     if requested by the Issuers or the Trustee, the delivery of an opinion of
     counsel, certification and/or other information satisfactory to each of
     them.

          (b) The following provisions shall apply with respect to any proposed
transfer of a Regulation S Note prior to the expiration of the Distribution
Compliance Period:

          (i)   a transfer of a Regulation S Note or a beneficial interest
     therein to a QIB shall be made upon the representation of the transferee
     that it is purchasing the 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 and acknowledges that it has received
     such information regarding the Issuers as the undersigned has requested
     pursuant to Rule 144A or has determined not to request such information and
     that it is aware that the transferor is relying upon its foregoing
     representations in order to claim the exemption from registration provided
     by Rule 144A;

          (ii)  a transfer of a Regulation S Note or a beneficial interest
     therein to an institutional accredited investor shall be made upon receipt
     by the Trustee or its agent of a certificate substantially in the form set
     forth in Section 308 from the proposed transferee and, if requested by the
     Issuers or the Trustee, the delivery of an opinion of counsel,
     certification and/or other information satisfactory to each of them; and

          (iii) a transfer of a Regulation S Note or a beneficial interest
     therein to a Non-U.S. Person shall be made upon receipt by the Trustee or
     its agent of a certificate substantially in the form set forth in Section
     309 from the transferor and, if requested by the Issuers or the Trustee,
     receipt by the Trustee or its agent of an opinion of counsel, certification
     and/or other information satisfactory to each of them.

          Prior to or on the expiration of the Distribution Compliance Period,
beneficial interests in a Regulation S Global Note may only be held through
Morgan Guaranty Trust Company of New York, Brussels Office, as operator of the
Euroclear System ("Euroclear") or Cedel Bank, societe anonyme ("Cedel") (as
indirect participants in DTC) or another agent member of Euroclear and Cedel
acting for and on behalf of them, unless exchanged for interests in the Rule
144A Global Note or the Institutional Accredited Investor Global Note in
accordance with the certification requirements hereof. During the Distribution
Compliance Period, interests in the Regulation S Global Note, if any, may be
exchanged for interests in the Rule 144A Global Note, the Institutional
Accredited Investor Global Note or for Certificated Notes only in accordance
with the requirements described in Section 201.

          After the expiration of the Distribution Compliance Period, interests
in the Regulation S Note may be transferred without requiring certification set
forth in Section 308 or 309 or any additional certification.

          (c) Private Placement Legend.  Upon the transfer, exchange or
              -------------------------                                
replacement of Notes not bearing the Private Placement Legend, the Note
Registrar shall deliver Notes that do not bear the Private Placement Legend.
Upon the transfer, exchange or replacement of Notes bearing the Private

                                       45
<PAGE>
 
Placement Legend, the Note Registrar shall deliver only Notes that bear the
Private Placement Legend unless there is delivered to the Note Registrar an
Opinion of Counsel reasonably satisfactory to the Issuers and the Trustee to the
effect that neither such legend nor the related restrictions on transfer are
required in order to maintain compliance with the provisions of the Securities
Act.

          (d) General.  By its acceptance of any Note bearing the Private
              -------                                                    
Placement Legend, each Holder of such a Note acknowledges the restrictions on
transfer of such Note set forth in this Indenture and in the Private Placement
Legend and agrees that it will transfer such Note only as provided in this
Indenture.

          (e) The Issuers shall deliver to the Trustee an Officers' Certificate
setting forth the dates on which the Distribution Compliance  Period terminates.

          The Note Registrar shall retain copies of all letters, notices and
other written communications received pursuant to Section 306 or this Section
307. The Issuers shall have the right to inspect and make copies of all such
letters, notices or other written communications at any reasonable time upon the
giving of reasonable written notice to the Note Registrar.

          (f) No Obligation of the Trustee.  (i)  The Trustee shall have no
              ----------------------------                                 
responsibility or obligation to any beneficial owner of a Global Note, a member
of, or a participant in the Depository or other Person with respect to any
ownership interest in the Notes, with respect to the accuracy of the records of
the Depository or its nominee or of any participant or member thereof or with
respect to the delivery to any participant, member, beneficial owner or other
Person (other than the Depository) of any notice (including any notice of
redemption) or the payment of any amount, under or with respect to such Notes.
All notices and communications to be given to the Holders and all payments to be
made to Holders under the Notes shall be given or made only to the registered
Holders (which shall be the Depository or its nominee in the case of a Global
Note). The rights of beneficial owners in any Global Note in global form shall
be exercised only through the Depository subject to the applicable rules and
procedures of the Depository. The Trustee may rely and shall be fully protected
and indemnified pursuant to Section 607 in relying upon information furnished by
the Depository with respect to any beneficial owners, its members and
participants.

          (ii) The Trustee shall have no obligation or duty to monitor,
determine or inquire as to compliance with any restrictions on transfer imposed
under this Indenture or under applicable law with respect to any transfer of any
interest in any Note (including without limitation any transfers between or
among Depository participants, members or beneficial owners in any Global Note)
other than to require delivery of such certificates and other documentation of
evidence as are expressly required by, and to do so if and when expressly
required by, the terms of this Indenture, and to examine the same to determine
substantial compliance as to form with the express requirements hereof.

                                       46
<PAGE>
 
          SECTION 308.  Form of Certificate to Be Delivered in Connection with
                        ------------------------------------------------------
                        Transfers to Institutional Accredited Investors.
                        ----------------------------------------------- 

                                     [date]

     MEDIACOM LLC
     MEDICACOM CAPITAL CORPORATION
     c/o  Bank of Montreal Trust Company, as Trustee
     88 Pine Street, 19th Floor
     New York, New York 10005
     Attention: Corporate Trust Administration

Ladies and Gentlemen:

          This certificate is delivered to request a transfer of $_______
principal amount of the 7 7/8% Senior Notes due 2011 (the "Notes") of Mediacom
LLC and Mediacom Capital Corporation (the "Issuers").

          Upon transfer, the Notes would be registered in the name of the new
beneficial owner as follows:


          Name:
          Address:
          Taxpayer ID Number:

          The undersigned represents and warrants to you that:

          (1) We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) under the Securities Act of 1933, as amended (the
"Securities Act")), purchasing for our own account or for the account of an
institutional "accredited investor" at least $250,000 principal amount of the
Notes, and we are acquiring the Notes not with a view to, or for offer or sale
in connection with, any distribution in violation of the Securities Act. We have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Notes and invest in
or purchase securities similar to the Notes in the normal course of our
business. We and any accounts for which we are acting are each able to bear the
economic risk of our or its investment.

          (2) We understand that the Notes have not been registered under the
Securities Act and, unless so registered, may not be sold except as permitted in
the following sentence. We agree on our own behalf and on behalf of any investor
account for which we are purchasing Notes to offer, sell or otherwise transfer
such Notes prior to the date which is two years after the later of the date of
original issue and the last date on which the Issuers or any affiliate of the
Issuers was the owner of such Notes (or any predecessor thereto) (the "Resale
Restriction Termination Date") only (a) to the Issuers, (b) pursuant to a
registration statement that has been declared effective under the Securities
Act, (c) in a transaction complying with the requirements of Rule 144A under the
Securities Act ("Rule 144A"), to a person we reasonably believe is a qualified
institutional buyer under Rule 144A (a "QIB") that purchases for its own account
or for the account of a QIB and to whom notice is given that the transfer is
being made in reliance on Rule 144A, (d) pursuant to offers and sales that occur
outside the United States within the meaning of

                                       47
<PAGE>
 
Regulation S under the Securities Act, (e) to an institutional "accredited
investor" within the meaning of Rule 501 (a)(1), (2), (3) or (7) under the
Securities Act that is purchasing for its own account or for the account of such
an institutional "accredited investor", in each case in a minimum principal
amount of Notes of $250,000 or (f) pursuant to any other available exemption
from the registration requirements of the Securities Act, subject in each of the
foregoing cases to any requirement of law that the disposition of our property
or the property of such investor account or accounts be at all times within our
or their control and in compliance with any applicable state securities laws.
The foregoing restrictions on resale will not apply subsequent to the Resale
Restriction Termination Date. If any resale or other transfer of the Notes is
proposed to be made pursuant to clause (e) above prior to the Resale Restriction
Termination Date, the transferor shall deliver a letter from the transferee
substantially in the form of this letter to the Issuers and the Trustee, which
shall provide, among other things, that the transferee is an institutional
"accredited investor" within the meaning of Rule 501 (a)(1), (2), (3) or (7)
under the Securities Act and that it is acquiring such Notes for investment
purposes and not for distribution in violation of the Securities Act. Each
purchaser acknowledges that the Issuers and the Trustee reserve the right prior
to any offer, sale or other transfer prior to the Resale Termination Date of the
Notes pursuant to clause (d), (e) or (f) above to require the delivery of an
opinion of counsel, certifications and/or other information satisfactory to the
Issuers and the Trustee.


                                         TRANSFEREE:
                                                    -------------------------
        
                                         BY:
                                            ---------------------------------


Upon transfer the Notes would be registered in the name of the new beneficial
owner as follows:

        Name                     Address                Taxpayer ID
        ----                     -------                -----------
                                                        Number:
                                                        -------
 



Very truly yours,


[Name of Transferor]

By:____________________    _______________________________
   Name:                   Signature Medallion Guaranteed
   Title:

                                       48
<PAGE>
 
          SECTION 309.  Form of Certificate to Be Delivered in Connection with
                        ------------------------------------------------------
                        Transfers Pursuant to Regulation S.
                        ---------------------------------- 

                                     [date]

Bank of Montreal Trust Company, as Trustee
88 Pine Street, 19th Floor
New York, New York 10005
Attention: Corporate Trust Administration

                 Re:  Mediacom LLC and Mediacom Capital Corporation (the
                      "Issuers" 7 7/8% Senior Notes due 2011 (the "Notes")
                      -----------------------------------------------------

Ladies and Gentlemen:

          In connection with our proposed sale of $__________ aggregate
principal amount of the Notes, we confirm that such sale has been effected
pursuant to and in accordance with Regulation S under the United States
Securities Act of 1933, as amended (the "Securities Act"), and, accordingly, we
represent that:

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

          (b) either (i) at the time the buy order was originated, the
     transferee was outside the United States or we and any person acting on our
     behalf reasonably believed that the transferee was outside the United
     States or (ii) the transaction was executed in, on or through the
     facilities of a designated off-shore securities market and neither we nor
     any person acting on our behalf knows that the transaction has been pre-
     arranged with a buyer in the United States;

          (c) no directed selling efforts have been made in the United States in
     contravention of the requirements of Rule 903(b) or Rule 904(b) of
     Regulation S, as applicable; and

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

          In addition, if the sale is made during a distribution compliance
period and the provisions of Rule 903(c)(3) or Rule 904(c)(1) of Regulation S
are applicable thereto, we confirm that such sale has been made in accordance
with the applicable provisions of Rule 903(c)(3) or Rule 904(c)(1), as the case
may be.

          You and the Issuers are entitled to rely upon this letter and are
irrevocably authorized to produce this letter or a copy hereof to any interested
party in any administrative or legal proceedings or official inquiry with
respect to the matters covered hereby. Terms used in this certificate have the
meanings set forth in Regulation S.

          Very truly yours,

          [Name of Transferor]

          By:____________________  ____________________________
             Authorized Signature  Signature Medallion Guaranteed

                                       49
<PAGE>
 
          SECTION 310.  Mutilated, Destroyed, Lost and Stolen Notes.
                        ------------------------------------------- 

          If (i) any mutilated Note is surrendered to the Trustee, or (ii) the
Issuers and the Trustee receive evidence to their satisfaction of the
destruction, loss or theft of any Note, and there is delivered to the Issuers
and the Trustee such security or indemnity, in each case, as may be required by
them to save each of them harmless, then, in the absence of notice to the
Issuers or the Trustee that such Note has been acquired by a bona fide
purchaser, the Issuers shall execute and upon Authentication Order the Trustee
shall authenticate and deliver, in exchange for any such mutilated Note or in
lieu of any such destroyed, lost or stolen Note, a new Note of like tenor and
principal amount, bearing a number not contemporaneously outstanding.

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

          Upon the issuance of any new Note under this Section, the Issuers may
require the payment 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) in connection therewith.

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

          The provisions of this Section 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 311.  Payment of Interest; Interest Rights Preserved.
                        ---------------------------------------------- 

          Interest on any Note which is payable, and is punctually paid or duly
provided for, on any interest payment date shall be paid to the Person in whose
name such Note (or one or more predecessor Notes) is registered at the close of
business on the Regular Record Date for such interest at the office or agency of
the Issuers maintained for such purpose pursuant to Section 1002; provided,
however, that each installment of interest may at the Issuers' option be paid by
(i) mailing a check for such interest, payable to or upon the written order of
the Person entitled thereto pursuant to Section 312, to the address of such
Person as it appears in the Note Register or (ii) wire transfer to an account
located in the United States maintained by the payee.

          Any interest on any Note which is payable, but is not paid when the
same becomes due and payable and such nonpayment continues for a period of 30
days shall forthwith cease to be payable to the Holder on the Regular Record
Date by virtue of having been such Holder, and such defaulted interest and (to
the extent lawful) interest on such defaulted interest at the rate borne by the
Notes (such defaulted interest and interest thereon herein collectively called
"Defaulted Interest") shall be paid by the Issuers, at their election in each
case, as provided in clause (a) or (b) below:

          (a) The Issuers may elect to make payment of any Defaulted Interest to
     the Persons in whose names the Notes (or their respective predecessor
     Notes) are registered at the close of business on a Special Record Date for
     the payment of such Defaulted Interest, which shall be

                                       50
<PAGE>
 
     fixed in the following manner. The Issuers shall notify the Trustee in
     writing of the amount of Defaulted Interest proposed to be paid on each
     Note and the date (not less than 30 days after such notice) of the proposed
     payment (the "Special Interest Payment Date"), and at the same time the
     Issuers shall deposit with the Trustee an amount of money 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 money when deposited to be
     held in trust for the benefit of the Persons entitled to such Defaulted
     Interest as in this clause provided. Thereupon the Trustee shall fix a
     record date (the "Special Record Date") for the payment of such Defaulted
     Interest which shall be not more than 15 days and not less than 10 days
     prior to the Special Interest Payment Date and not less than 10 days after
     the receipt by the Trustee of the notice of the proposed payment. The
     Trustee shall promptly notify the Issuers of such Special Record Date, and
     in the name and at the expense of the Issuers, shall cause notice of the
     proposed payment of such Defaulted Interest and the Special Record Date and
     Special Interest Payment Date therefor to be given in the manner provided
     for in Section 106, not less than 10 days prior to such Special Record
     Date. Notice of the proposed payment of such Defaulted Interest and the
     Special Record Date and Special Interest Payment Date therefor having been
     so given, such Defaulted Interest shall be paid on the Special Interest
     Payment Date to the Persons in whose names the Notes (or their respective
     predecessor Notes) are registered at the close of business on such Special
     Record Date and shall no longer be payable pursuant to the following clause
     (b).

          (b) The Issuers may make payment of any Defaulted Interest in any
     other lawful manner not inconsistent with the requirements of any
     securities exchange on which the Notes may be listed, and upon such notice
     as may be required by such exchange, if, after notice given by the Issuers
     to the Trustee of the proposed payment pursuant to this clause, such manner
     of payment shall be deemed practicable by the Trustee.

          Subject to the foregoing provisions of this Section, 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 312.  Persons Deemed Owners.
                        --------------------- 

          Prior to the due presentment of a Note for registration of transfer,
the Issuers, the Trustee and any agent of the Issuers or the Trustee may treat
the Person in whose name such Note is registered as the owner of such Note for
the purpose of receiving payment of principal of (and premium, if any) and
(subject to Sections 305 and 311 ) interest on such Note and for all other
purposes whatsoever, whether or not such Note be overdue, and none of the
Issuers, the Trustee nor any agent of the Issuers or the Trustee shall be
affected by notice to the contrary.

                                       51
<PAGE>
 
          SECTION 313.  Cancellation.
                        ------------ 

          All Notes surrendered for payment, redemption, registration of
transfer or exchange shall, if surrendered to any Person other than the Trustee,
be delivered to the Trustee and shall be promptly cancelled by it. If the
Issuers shall acquire any of the Notes other than as set forth in the preceding
sentence, the acquisition shall not operate as a redemption or satisfaction of
the Indebtedness represented by such Notes unless and until the same are
surrendered to the Trustee for cancellation pursuant to this Section 313.  No
Notes shall be authenticated in lieu of or in exchange for any Notes cancelled
as provided in this Section, except as expressly permitted by this Indenture.
All cancelled Notes held by the Trustee shall be destroyed by the Trustee and
the Trustee shall send a certificate of such destruction to the Issuers.

          SECTION 314.  Computation of Interest.
                        ----------------------- 

          Interest on the Notes shall be computed on the basis of a 360-day year
of twelve 30-day months.

          SECTION 315.  CUSIP Numbers.
                        ------------- 

          The Issuers in issuing Notes may use "CUSIP" numbers (if then
generally in use) in addition to serial numbers; if so, the Trustee shall use
such "CUSIP" numbers in addition to serial numbers in notices of redemption and
repurchase as a convenience to Holders; provided that any such notice may state
that no representation is made as to the correctness of such CUSIP numbers,
either as printed on the Notes or as contained in any notice of a redemption or
repurchase and that reliance may be placed only on the serial or other
identification numbers printed on the Notes, and any such redemption or
repurchase shall not be affected by any defect in or omission of such CUSIP
numbers. The Issuers will promptly notify the Trustee of any change in the CUSIP
numbers.


                                 ARTICLE FOUR.
                           SATISFACTION AND DISCHARGE

          SECTION 401.  Satisfaction and Discharge of Indenture.
                        --------------------------------------- 

          This Indenture shall upon the Issuers' Request cease to be of further
effect (except as to surviving rights of registration of transfer or exchange of
Notes expressly provided for herein or pursuant hereto) and the Trustee, at the
expense of the Issuers, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture when

          (i)  either

               (A) all Notes theretofore authenticated and delivered (other than
          (1) Notes which have been lost, stolen or destroyed and which have
          been replaced or paid as provided in Section 310 and (2) Notes for
          whose payment money has theretofore been deposited in trust with the
          Trustee or any Paying Agent or segregated and held in trust by the
          Issuers and thereafter repaid to the Issuers or discharged from such
          trust, as provided in Section 1003) have been delivered to the Trustee
          for cancellation; or

                                       52
<PAGE>
 
               (B) all Notes not theretofore delivered to the Trustee for
          cancellation

                   (1) have become due and payable by reason of the making of a
               notice of redemption or otherwise; or

                   (2) will become due and payable at their Stated Maturity
               within one year; or

                   (3) are to be called for redemption within one year under
               arrangements satisfactory to the Trustee for the giving of notice
               of redemption by the Trustee in the name, and at the expense, of
               the Issuers,

     and the Issuers in the case of (1), (2) or (3) above, have irrevocably
     deposited or caused to be deposited with the Trustee as trust funds in
     trust for such purpose an amount in cash or U.S. Government Obligations
     sufficient to pay and discharge the entire indebtedness on such Notes not
     theretofore delivered to the Trustee for cancellation, for principal of
     (and premium, if any) and interest to the date of such deposit (in the case
     of Notes which have become due and payable) or to the Stated Maturity or
     Redemption Date, as the case may be;

          (ii)  no Default or Event of Default with respect to this Indenture or
     the Notes shall have occurred and be continuing on the date of such deposit
     or shall occur as a result of such deposit and such deposit will not result
     in a breach or violation of, or constitute a default under, any other
     instrument or agreement to which the Issuers is a party or by which it is
     bound;

          (iii) the Issuers have paid or caused to be paid all sums payable
     hereunder by the Issuers in connection with all the Notes including all
     fees and expenses of the Trustee;

          (iv)  the Issuers have delivered irrevocable instructions to the
     Trustee to apply the deposited money toward the payment of such Notes at
     maturity or the Redemption Date, as the case may be; and

          (v)   the Issuers have 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 and the termination of the Issuers' obligation hereunder
     have been satisfied.

          Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Issuers to the Trustee under Section 607 and, if money shall
have been deposited with the Trustee pursuant to subclause (B) of clause (i) of
this Section, the obligations of the Trustee under Section 402 and the last
paragraph of Section 1003 shall survive any such satisfaction and discharge.

          SECTION 402.  Application of Trust Money.
                        -------------------------- 

          Subject to the provisions of the last paragraph of Section 1003, all
money deposited with the Trustee pursuant to Section 401 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
(including the Issuers acting as their own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the principal (and premium, if
any) and interest for whose payment such money has been deposited with the
Trustee; but such money need not be segregated from other funds except to the
extent required by law.

                                       53
<PAGE>
 
          If the Trustee or Paying Agent is unable to apply any money or U.S.
Government Obligations in accordance with Section 401 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
Issuers' obligations under this Indenture and the Notes shall be revived and
reinstated as though no deposit had occurred pursuant to Section 401; provided
that if the Issuers have made any payment of principal of, premium, if any, or
interest on any Notes because of the reinstatement of its obligations, the
Issuers shall be subrogated to the rights of the Holders of such Notes to
receive such payment from the money or Government Obligations held by the
Trustee or Paying Agent.


                                 ARTICLE FIVE.
                                   REMEDIES

          SECTION 501.  Events of Default.
                        ----------------- 

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

          (i)   a default in the payment of principal of or premium, if any, on
     any Note when due at its Stated Maturity, upon optional redemption, upon
     required repurchase, upon declaration or otherwise;

          (ii)  a default in any payment of interest or Liquidated Damages, if
     any, on any Note when due, continued for 30 days;

          (iii) the failure by either of the Issuers or any Guarantor to comply
     for 60 days after written notice by holders of not less than 25% in
     principal amount of the Notes then outstanding with any other covenant,
     representation, warranty or other agreement  contained in this Indenture or
     the Notes;

          (iv)  default in the payment at maturity (continued for the longer of
     any applicable grace period or 30 days) of any Indebtedness aggregating
     $15,000,000 or more of the Issuers or any Significant Subsidiary or any
     group of Restricted Subsidiaries of Mediacom which, if merged into each
     other, would constitute a Significant Subsidiary, or the acceleration of
     any such Indebtedness which default shall not be cured or waived, or such
     acceleration shall not be rescinded or annulled, within 30 days after the
     written notice by the holders of not less than 25% in principal amount of
     the Notes then outstanding;

          (v)   any final judgment or judgments for the payment of money in
     excess of $15,000,000 (net of amounts covered by insurance) is rendered
     against the Issuers or any Significant Subsidiary or any group of
     Restricted Subsidiaries of Mediacom, which, if merged into each other,
     would constitute a Significant Subsidiary, and such judgment or judgements
     remain undischarged for any period of 60 consecutive days, during which a
     stay of enforcement of such judgment shall not be in effect;

                                       54
<PAGE>
 
          (vi)    either of the Issuers or a Significant Subsidiary or any group
     of Restricted Subsidiaries of Mediacom which, if merged into each other,
     would constitute a Significant Subsidiary, pursuant to or within the
     meaning of any Bankruptcy Law:

               (A) commences a voluntary case;

               (B) consents to the entry of an order for relief against it in an
          involuntary case;

               (C) consents to the appointment of a custodian of it or for all
          or substantially all of its property;

               (D) makes a general assignment for the benefit of its creditors;

               or takes any comparable action under any foreign laws relating to
          insolvency; or

          (vii)   a court of competent jurisdiction enters an order or decree
     under any Bankruptcy Law that:

               (A) is for relief against either of the Issuers or any
          Significant Subsidiary or any group of Restricted Subsidiaries of
          Mediacom which, if merged into each other, would constitute a
          Significant Subsidiary, in an involuntary case;

               (B) appoints a custodian of either of the Issuers or any
          Significant Subsidiary or any group of Restricted Subsidiaries of
          Mediacom which, if merged into each other, would constitute a
          Significant Subsidiary, for all or substantially all of its property;
          or

               (C) orders the winding up or liquidation of either of the Issuers
          or any Significant Subsidiary or any group of Restricted Subsidiaries
          of Mediacom which, if merged into each other, would constitute a
          Significant Subsidiary;

     or any similar relief is granted under any foreign laws and the order or
     decree remains unstayed and in effect for 90 consecutive days; or

          (viii)  any Restricted Subsidiary Guarantee ceases to be in full force
     and effect (except as contemplated by the terms of this Indenture) or any
     Guarantor denies or disaffirms its obligations under this Indenture or any
     Restricted Subsidiary Guarantee.

          The foregoing will constitute Events of Default whatever the reason
for any such Event of Default and whether it is voluntary or involuntary or is
effected by operation of law or pursuant to any judgment, decree or order of any
court or any order, rule or regulation of any administrative or governmental
body.

          The Issuers are required to deliver to the Trustee, within 120 days
after the end of each fiscal year of Mediacom, in accordance with Section 1016,
an Officers' Certificate stating whether or not the signers know of any Event of
Default, a description of the Event of Default and its status and what action
the Issuers are taking or propose to take in respect thereof.

          If a Default occurs and is continuing and is known to the Trustee, the
Trustee must mail to each holder, in accordance with Section 6.02, notice of the
Default within 90 days after it occurs. Except in the case of a Default in the
payment of principal of, premium, if any, or interest on any Note,

                                       55
<PAGE>
 
the Trustee may withhold notice if and so long as a committee of its Trust
Officers in good faith determines that withholding notice is in the interests of
the Holders of the Notes.

          SECTION 502.  Acceleration of Maturity; Rescission and Annulment.
                        -------------------------------------------------- 

          If an Event of Default (other than by reason of an Event of Default
specified in clause (vi) or (vii) of the first paragraph of Section 501) occurs
and is continuing, the Trustee by notice to the Issuers or the Holders of not
less than 25% in principal amount of the Notes then outstanding may declare the
principal and accrued and unpaid interest on all the Notes to be due and payable
immediately, by a notice in writing to the Issuers (and to the Trustee if given
by Holders). Upon the effectiveness of such declaration, such principal will be
due and payable immediately. Notwithstanding the foregoing, in the case of an
Event of Default specified in clause (vi) or (vii) of the first paragraph of
Section 501 occurs and is continuing, then the principal amount of all the Notes
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.

          The Holders of a majority in principal amount of the outstanding Notes
by notice to the Trustee may rescind an acceleration and its consequences if the
rescission would not conflict with any judgment or decree and if all existing
Events of Default have been cured or waived (except nonpayment of principal,
interest and premium, if any, that has become due solely because of
acceleration). The Trustee may rely upon such notice of rescission without any
independent investigation as to the satisfaction of the conditions in the
preceding sentence. No such rescission shall affect any subsequent Default or
impair any right consequent thereto.

          SECTION 503.  Collection of Indebtedness and Suits for Enforcement by
                        -------------------------------------------------------
Trustee.
------- 

          If an Event of Default specified in clause (i) or (ii) of the first
paragraph of Section 501 occurs and is continuing, the Trustee, in its own name
as trustee of an express trust, may institute a judicial proceeding for the
collection of the sums so due and unpaid, may prosecute such proceeding to
judgment or final decree and may enforce the same against the Issuers or any
other obligor upon the Notes and collect the moneys adjudged or decreed to be
payable in the manner provided by law out of the property of the Issuers or any
other obligor upon the Notes, wherever situated.

          If an Event of Default occurs and is continuing the Trustee may in its
discretion proceed to protect and enforce its rights and the rights of the
Holders under this Indenture 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, subject however to Section 513. No recovery of any such
judgment upon any property of the Issuers shall affect or impair any rights,
powers or remedies of the Trustee or the Holders.

          SECTION 504.  Trustee May File Proofs of Claim.
                        -------------------------------- 

          In case of the pendency of any receivership, insolvency, liquidation,
bankruptcy, reorganization, arrangement, adjustment, composition or other
judicial proceeding relative to the Issuers or any other obligor, upon the Notes
or the property of the Issuers or of such other obligor or their creditors, the
Trustee (irrespective of whether the principal of the 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 Issuers for the payment
of overdue principal, premium, if any, or interest) shall be entitled and
empowered, by intervention in such proceeding or otherwise,

                                       56
<PAGE>
 
          (i)  to file and prove a claim for the whole amount of principal (and
     premium, if any), interest and Liquidated Damages, if any, owing and unpaid
     in respect of the Notes, to take such other actions (including
     participating as a member, voting or otherwise, of any official committee
     of creditors appointed in such matter) and to file such other papers or
     documents and take such other actions as the Trustee (including,
     participation as a member of any creditors committee) may deem 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 of the Holders allowed in such
     judicial proceeding, and

          (ii) to collect and receive any moneys or other property payable or
     deliverable on any such claims and to distribute the same;

and any custodian in any such judicial 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 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 607.

          Nothing herein contained 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; provided, however, that the
Trustee may, on behalf of such Holders, vote for the election of a trustee in
bankruptcy or other similar official.

          SECTION 505.  Trustee May Enforce Claims Without Possession of 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 and 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 in respect of which such judgment has been recovered.

          SECTION 506.  Application of Money Collected.
                        ------------------------------ 

          Any money collected by the Trustee pursuant to this Article 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:

          FIRST:  To the payment of all amounts due the Trustee under Section
     607;

          SECOND:  To the payment of the amounts then due and unpaid for
     principal of (and premium and Liquidated Damages, if any) and interest on
     the Notes in respect of which or for the benefit of which such money has
     been collected, ratably, without preference or priority of any kind,
     according to the amounts due and payable on such Notes for principal (and
     premium and Liquidated Damages, if any), and interest, respectively; and

          THIRD:  The balance, if any, to the Person or Persons entitled
     thereto, including the Issuers or any other obligor on the Notes, as their
     interests may appear or as a court of competent

                                       57
<PAGE>
 
     jurisdiction may direct, provided that all sums due and owing to the
     Holders and the Trustee have been paid in full as required by this
     Indenture.

          SECTION 507.  Limitation on Suits.
                        ------------------- 

          Except to enforce the right to receive payment of principal, premium,
if any, or interest when due, no holder may pursue any remedy with respect to
this Indenture or the Notes unless:

          (i)   such holder has previously given the Trustee notice that an
     Event of Default is continuing;

          (ii)  holders of at least 25% in principal amount of the outstanding
     Notes have requested the Trustee to pursue the remedy;

          (iii) such holders have offered the Trustee reasonable security or
     indemnity against any loss, liability or expense;

          (iv)  the Trustee has not complied with such request within 60 days
     after the receipt of the request and the offer of security or indemnity;
     and

          (v)   the holders of a majority in principal amount of the outstanding
     Notes have not given the Trustee a direction that, in the opinion of the
     Trustee, is inconsistent with such request within such 60-day period.

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

          SECTION 508.  Unconditional Right of Holders to Receive Principal,
                        ----------------------------------------------------
Premium and Interest.
-------------------- 

          Notwithstanding any other provision in this Indenture the Holder of
any Note shall have the right, which is absolute and unconditional, to receive
payment, as provided herein (including, if applicable, Article Eleven) and in
such Note of the principal of (and premium, if any) and (subject to Section 311)
interest and Liquidated Damages, if any, on such Note on the respective Stated
Maturities expressed in such Note (or, in the case of redemption or repurchase,
on the Redemption Date or repurchase) and to institute suit for the enforcement
of any such payment, and such rights shall not be impaired without the consent
of such Holder.

          SECTION 509.  Restoration of Rights and Remedies.
                        ---------------------------------- 

          If the Trustee or any Holder 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, subject to any
determination in such proceeding, the Issuers, any other obligor on the Notes,
the Trustee and the Holders shall 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.

                                       58
<PAGE>
 
          SECTION 510.  Rights and Remedies Cumulative.
                        ------------------------------ 

          Except as otherwise provided with respect to the replacement or
payment of mutilated, destroyed, lost or stolen Notes in the last paragraph of
Section 310, 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 511.  Delay or Omission Not Waiver.
                        ---------------------------- 

          No delay or omission of the Trustee or of any Holder 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 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.

          SECTION 512.  Control by Holders.
                        ------------------ 

          Subject to certain restrictions, the holders of a majority in
principal amount of the outstanding Notes are given the right to direct the
time, method and place of conducting any proceeding for any remedy available to
the Trustee or of exercising any trust or power conferred on the Trustee,
provided that

          (i)   such direction shall not be in conflict with any rule of law or
     this Indenture;

          (ii)  the Trustee need not take any action which might be unduly
     prejudicial to the rights of any other Holder or would involve the Trustee
     in personal liability; and

          (iii) subject to the provisions of Section 315 of the Trust Indenture
     Act, the Trustee may take any other action deemed proper by the Trustee
     which is not inconsistent with such direction.

          Prior to taking any action under this Indenture, the Trustee shall be
entitled to indemnification satisfactory to it in its sole discretion against
all losses and expenses caused by taking or not taking such action.

          SECTION 513.  Waiver of Past Defaults.
                        ----------------------- 

          Subject to Sections 508 and 902, the Holders of a majority in
aggregate principal amount of the outstanding Notes (including consents obtained
in connection with a tender offer or exchange offer for the Notes) may on behalf
of the Holders of all the Notes, by written notice to the Trustee, waive any
existing Default or Event of Default and its consequences under this Indenture
except a continuing Default or Event of Default in the payment of interest or
Liquidated Damages, if any, on or the principal of, any such Note held by a non-
consenting Holder, or in respect of a covenant or a provision which cannot be
amended or modified without the consent of the Holders of each outstanding Note
affected thereby.

          In the event that any Event of Default specified in clause (iv) of the
first paragraph of Section 501 shall have occurred and be continuing, such Event
of Default and all consequences thereof (including without limitation any
acceleration or resulting payment default) shall be annulled, waived and

                                       59
<PAGE>
 
rescinded, automatically and without any action by the Trustee or the Holders of
the Notes, if within 30 days after such Event of Default arose (i) the
Indebtedness that is the basis for such Event of Default has been discharged, or
(ii) the holders thereof have rescinded or waived the acceleration, notice or
action (as the case may be) giving rise to such Event of Default, or (iii) if
the Default that is the basis for such Event of Default has been cured.

          Upon any such waiver, such Default shall cease to exist, and any Event
of Default arising therefrom shall be deemed to have been cured, for every
purpose of this Indenture; but no such waiver shall extend to any subsequent or
other Default or Event of Default or impair any right consequent thereon.

          SECTION 514.  Undertaking for Costs.
                        --------------------- 

          All parties to this Indenture agree, and each Holder of any Note by
his 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 may in
its discretion assess reasonable costs, including reasonable attorneys' fees and
expenses, 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 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 of or interest or Liquidated Damages, if any, on any Note on or after
the respective Stated Maturities expressed in such Note (or, in the case of
redemption, on or after the Redemption Date).


                                  ARTICLE SIX.
                                  THE TRUSTEE

          SECTION 601.  Certain Duties and Responsibilities.
                        ----------------------------------- 

          (a) Except during the continuance of a Default or an Event of Default,

              (i)  the Trustee undertakes to perform such duties and only such
     duties as are specifically set forth in this Indenture, and the Trustee
     should not be liable except for the performance of such duties as
     specifically set forth in this Indenture and no others; and no implied
     covenants or obligations shall be read into this Indenture against the
     Trustee; and

              (ii) in the absence of bad faith or willful misconduct 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; but in the case of any such certificates or opinions, the
     Trustee shall be under a duty to examine the same to determine whether or
     not they conform to the requirements of this Indenture, but not to verify
     the contents thereof.

              (b) In case a Default or an Event of Default has occurred and is
     continuing of which a Trust Officer of the Trustee has actual knowledge or
     of which written notice of such Default or Event of Default shall have been
     given to the Trustee of the Issuers, any other obligor of the Notes or by
     any Holder, the Trustee shall exercise such of the rights and powers vested
     in it

                                       60
<PAGE>
 
     by this Indenture, and use the same degree of care and skill in their
     exercise, as a prudent man would exercise or use under the circumstances in
     the conduct of his own affairs.

               (c) No provision of this Indenture shall be construed to relieve
     the Trustee from liability for its own negligent action, its own negligent
     failure to act, or its own willful misconduct, except that

               (i)   this paragraph (c) shall not be construed to limit the
     effect of paragraph (a) of this Section;

               (ii)  the Trustee shall not be liable for any error of judgment
     made in good faith by a Trust Officer, unless it shall be proved that the
     Trustee was negligent in ascertaining the pertinent facts;

               (iii) the Trustee shall not be liable with respect to any action
     taken or omitted to be taken by it in good faith in accordance with the
     direction of the Holders of a majority in aggregate principal amount of the
     outstanding 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, and

               (iv)  the Trustee shall not be required to examine any of the
     reports, information or documents filed with it pursuant to Section 1014 to
     determine whether there has been any breach of the covenants of the Issuers
     set forth in Sections 1004 through 1013.

               (d) Whether or not therein expressly so provided, 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 Section and to the TIA.

          SECTION 602.  Notice of Defaults.
                        ------------------ 

          Within 90 days after the occurrence of any Default hereunder, the
Trustee shall transmit in the manner and to the extent provided in TIA (S)
313(c), notice of such Default hereunder actually known to a Trust Officer of
the Trustee, unless such Default shall have been cured or waived; provided,
however, that, except in the case of a Default in the payment of the principal
of (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. Notwithstanding anything to the contrary expressed
in this Indenture, the Trustee shall not be deemed to have knowledge of any
Default or Event of Default hereunder unless and until the Trustee shall have
received written notice thereof from the Issuers at its principal Corporate
Trust Office as specified in Section 105, except in the case of an Event of
Default under clause (i) or (ii) of the first paragraph of Section 501 (provided
that the Trustee is the Paying Agent).

          SECTION 603.  Certain Rights of Trustee.
                        ------------------------- 

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

                                       61
<PAGE>
 
          (b) Subject to the provisions of TIA (S)(S) 315(a) through 315(d):

              (i)   the Trustee may conclusively rely and shall be protected in
     acting or refraining from acting upon (whether in its original or facsimile
     form) any resolution, certificate, statement, instrument, opinion, report,
     notice, request, direction, consent, order, bond, debenture, note, other
     evidence of indebtedness or other paper or document believed by it to be
     genuine and to have been signed or presented by the proper party or parties
     and the Trustee need not investigate any fact or matter stated in the
     documents;

              (ii)   any request or direction of the Issuers mentioned herein
     shall be sufficiently evidenced by a Issuers' Request or Authentication
     Order and any resolution of the Executive Committee may be sufficiently
     evidenced by a Committee Resolution;

              (iii)  whenever in the administration of this Indenture the
     Trustee shall deem it desirable that a matter be proved or established
     prior to taking, suffering or omitting any action hereunder, the Trustee
     (unless other evidence be herein specifically prescribed) may, in the
     absence of bad faith or willful misconduct on its part, request and rely
     upon an Officers' Certificate or an Opinion of Counsel and shall not liable
     for any action it takes or omits to take in good faith reliance on such
     Officers' Certificate or Opinion of Counsel;

              (iv)   the Trustee may consult with counsel of its selection and
     any 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;

              (v)    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 reasonable security or indemnity
     satisfactory to the Trustee against the costs, expenses, losses and
     liabilities which might be incurred by it in compliance with such request
     or direction;

              (vi)   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, note, other evidence of indebtedness 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
     Issuers, personally or by agent or attorney;

              (vii)  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
     misconduct or negligence on the part of any agent or attorney appointed
     with due care by it hereunder; and

              (viii) the Trustee shall not be liable for any action taken,
     suffered or omitted by it in good faith and reasonably believed by it to be
     authorized or within the discretion or rights or powers conferred upon it
     by this Indenture; provided, however, that the Trustee's conduct does not
     constitute willful misconduct or negligence.

          (c) The Trustee shall not be required 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

                                       62
<PAGE>
 
its rights or powers if it shall have reasonable grounds for believing that
repayment of such funds or adequate indemnity against such risk or liability is
not reasonably assured to it.

          SECTION 604.  Trustee Not Responsible for Recitals or Issuance of
                        ---------------------------------------------------
Notes.
----- 

          The recitals contained herein and in the Notes, except for the
Trustee's certificates of authentication, shall be taken as the statements of
the Issuers, and the Trustee assumes no responsibility for their correctness and
it shall not be responsible for the Mediacom's use of the proceeds from the
Notes. The Trustee makes no representations as to the validity or sufficiency of
this Indenture or of the Notes, except that the Trustee represents that it is
duly authorized to execute and deliver this Indenture, authenticate the Notes
and perform its obligations hereunder and that the statements made by it in a
Statement of Eligibility on Form T-1 supplied to the Issuers are true and
accurate, subject to the qualifications set forth therein. The Trustee shall not
be accountable for the use or application by the Issuers of the proceeds of the
Notes.

          SECTION 605.  May Hold Notes.
                        -------------- 

          The Trustee, any Paying Agent, any Note Registrar, any Authenticating
Agent or any other agent of the Issuers or of the Trustee, in its individual or
any other capacity, may become the owner or pledgee of Notes and, subject to TIA
(S)(S) 310(b) and 311, may otherwise deal with the Issuers with the same rights
it would have if it were not Trustee, Paying Agent, Note Registrar,
Authenticating Agent or such other agent.

          SECTION 606.  Money Held in Trust.
                        ------------------- 

          All moneys received by the Trustee shall, until used or applied as
herein provided, be held in trust hereunder for the purposes for which they were
received, but need not be segregated from other funds except to the extent
required by law. The Trustee shall be under no liability for interest on any
money received by it hereunder except as otherwise agreed in writing with the
Issuers.

          SECTION 607.  Compensation and Reimbursement.
                        ------------------------------ 

          The Issuers agree:

          (i)   to pay to the Trustee from time to time such compensation as
     shall be agreed to in writing between the Issuers and the Trustee for all
     services rendered by it hereunder (which compensation shall not be limited
     by any provision of law in regard to the compensation of a trustee of an
     express trust);

          (ii)  except as otherwise expressly provided herein, to reimburse the
     Trustee upon its request for all reasonable expenses, disbursements and
     advances incurred or made by the Trustee in accordance with any provision
     of this Indenture (including the reasonable compensation and the expenses
     and disbursements of its agents, consultants and counsel and costs and
     expenses of collection), except any such expense, disbursement or advance
     as may be attributable to its negligence or bad faith; and

          (iii) to indemnify each of the Trustee or any predecessor Trustee
     (and their respective directors, officers, stockholders, employees and
     agents) for, and to hold them harmless against, any and all loss, damage,
     claim, liability or expense, including taxes (other than taxes based on the
     income of the Trustee) incurred without negligence, willful misconduct or
     bad faith on their part, arising out of or in connection with the
     acceptance or administration of this trust, including

                                       63
<PAGE>
 
     the costs and expenses of defending themselves against any claim or
     liability in connection with the exercise or performance of any of the
     Trustee's powers or duties hereunder.

          The obligations of the Issuers under this Section to compensate the
Trustee, to pay or reimburse the Trustee for expenses, disbursements and
advances and to indemnify and hold harmless the Trustee shall constitute
additional indebtedness hereunder and shall survive the satisfaction and
discharge of this Indenture. As security for the performance of such obligations
of the Issuers, the Trustee shall have a lien prior to the Holders of the Notes
upon all property and funds held or collected by the Trustee as such, except
funds held in trust for the payment of principal of (and premium, if any) or
interest on particular Notes.

          When the Trustee incurs expenses or renders services in connection
with an Event of Default specified in clause (vi) or (vii) of Section 501, the
expenses (including the reasonable charges and expenses of its counsel) of and
the compensation for such services are intended to constitute expenses of
administration under any applicable federal or state bankruptcy, insolvency or
other similar law.

          The provisions of this Section shall survive the termination of this
Indenture.

          SECTION 608.  Corporate Trustee Required; Eligibility.
                        --------------------------------------- 

          There shall be at all times a Trustee hereunder which shall be
eligible to act as Trustee under TIA (S) 310(a)(1), and which may have an office
in The City of New York and shall have individually, or on a consolidated basis
with a bank holding company of which it is a direct or indirect wholly owned
subsidiary, a combined capital and surplus of at least $50,000,000. If the
Trustee does not have an office in The City of New York, the Trustee may appoint
an agent in The City of New York reasonably acceptable to the Issuers to conduct
any activities which the Trustee may be required under this Indenture to conduct
in The City of New York. If such corporation or its parent holding company
publishes reports of condition at least annually, pursuant to law or to the
requirements of federal, state, territorial or District of Columbia supervising
or examining authority, then for the purposes of this Section 608, the combined
capital and surplus of such corporation or its parent shall be deemed to be its
combined capital and surplus as set forth in its most recent report of condition
so published. If at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 608, it shall resign immediately
in the manner and with the effect hereinafter specified in this Article.

          SECTION 609.  Resignation and Removal; Appointment of Successor.
                        ------------------------------------------------- 

          (a) No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee in accordance with the
applicable requirements of this Section.

          (b) The Trustee may resign at any time by giving written notice
thereof to the Issuers. Upon receiving such notice of resignation, the Issuers
shall promptly appoint a successor trustee by written instrument executed by
authority of the Executive Committee, a copy of which shall be delivered to the
resigning Trustee and a copy to the successor trustee. If an instrument of
acceptance required by this Section shall not have been delivered to the Trustee
within 30 days after the giving of such notice of resignation, the resigning
Trustee may petition, at the expense of the Issuers, 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 Issuers. The 

                                       64
<PAGE>
 
Trustee so removed may, at the expense of the Issuers, petition any court of
competent jurisdiction for the appointment of a successor Trustee if no
successor Trustee is appointed within 30 days of such removal.

          (d)  If at any time:

               (i)   the Trustee shall fail to comply with the provisions of TIA
     (S) 310(b) after written request therefor by the Issuers or by any Holder
     who has been a bona fide Holder of a Note for at least six months, or

               (ii)  the Trustee shall cease to be eligible under Section 608
     and shall fail to resign after written request therefor by the Issuers or
     by any Holder who has been a bona fide Holder of a Note for at least six
     months, or

               (iii) the Trustee shall become incapable of acting or shall be
     adjudged a bankrupt or insolvent or a custodian of the Trustee or of its
     property shall be appointed or any public officer shall take charge or
     control of the Trustee or of its property or affairs for the purpose of
     rehabilitation, conservation or liquidation,

then, in any such case, (A) the Issuers, by a Committee Resolution, may remove
the Trustee, or (B) subject to TIA (S) 315(e), any Holder who has been a bona
fide Holder of a Note for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
removal of the Trustee and the appointment of a successor Trustee.

          (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
Issuers, by a Committee Resolution, shall promptly appoint a successor Trustee.
If, within one year after such resignation, removal or incapability, or the
occurrence of such vacancy, a successor Trustee shall be appointed by Act of the
Holders of a majority in principal amount of the outstanding Notes delivered to
the Issuers and the retiring Trustee, the successor Trustee so appointed shall,
forthwith upon its acceptance of such appointment, become the successor Trustee
and supersede the successor Trustee appointed by the Issuers. If no successor
Trustee shall have been so appointed by the Issuers or the Holders and accepted
appointment in the manner hereinafter provided, any Holder who has been a bona
fide Holder of a Note for at least six months may, at the expense of the Issuers
on behalf of himself and all others similarly situated, petition any court of
competent jurisdiction for the appointment of a successor Trustee.

          (f) The Issuers shall give notice of each resignation and each removal
of the Trustee and each appointment of a successor Trustee to the Holders of
Notes in the manner provided for in Section 106. Each notice shall include the
name of the successor Trustee and the address of its Corporate Trust Office.

          SECTION 610.  Acceptance of Appointment by Successor.
                        -------------------------------------- 

          Every successor Trustee appointed hereunder shall execute, acknowledge
and deliver to the Issuers 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 Issuers 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 retiring Trustee hereunder. Notwithstanding the replacement of the Trustee
pursuant to this Section 610, the Issuers' obligations under Section 607 shall

                                       65
<PAGE>
 
continue for the benefit of the retiring Trustee with regard to expenses and
liabilities incurred by it and compensation earned by it prior to such
replacement or otherwise under this Indenture. Upon request of any such
successor Trustee, the Issuers 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.

          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.

          SECTION 611.  Merger, Conversion, Consolidation or Succession to
                        --------------------------------------------------
Business.
-------- 

          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 such corporation shall be otherwise qualified and eligible under this
Article, 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 case at
that time any of the Notes shall not have been authenticated, any successor
Trustee may authenticate such Notes either in the name of any predecessor
hereunder or in the name of the successor Trustee. In all such cases such
certificates shall have the full force and effect which this Indenture provides
for the certificate of authentication of the Trustee shall have; provided,
however, that the right to adopt the certificate of authentication of any
predecessor Trustee or to authenticate Notes in the name of any predecessor
Trustee shall apply only to its successor or successors by merger, conversion or
consolidation.

          SECTION 612.  Trustee's Application for Instructions from the Issuers.
                        ------------------------------------------------------- 

          Any application by the Trustee for written instructions from the
Issuers may, at the option of the Trustee, set forth in writing any action
proposed to be taken or omitted by the Trustee under this Indenture and the date
on and/or after which such action shall be taken or such omission shall be
effective. Subject to Section 610, the Trustee shall not be liable for any
action taken by, or omission of, the Trustee in accordance with a proposal
included in such application on or after the date specified in such application
(which date shall not be less than three Business Days after the date any
officer of the Issuers actually receives such application, unless any such
officer shall have consented in writing to any earlier date) unless prior to
taking any such action (or the effective date in the case of an omission), the
Trustee shall have received written instructions in response to such application
specifying the action to be taken or omitted.

                                       66
<PAGE>
 
                                 ARTICLE SEVEN.
                          HOLDERS LISTS AND REPORTS BY
                            TRUSTEE AND THE ISSUERS

          SECTION 701.  The Issuers to Furnish Trustee Names and Addresses.
                        -------------------------------------------------- 

          The Issuers will furnish or cause to be furnished to the Trustee

          (a) semiannually, not more than 10 days after each Regular Record
     Date, a list, in such form as the Trustee may reasonably require, of the
     names and addresses of the Holders as of such Regular Record Date; and

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

provided, however, that if and so long as the Trustee shall be the Note
Registrar, no such list need be furnished.

          SECTION 702.  Disclosure of Names and Addresses of Holders.
                        -------------------------------------------- 

          Every Holder of Notes, by receiving and holding the same, agrees with
the Issuers and the Trustee that none of the Issuers or the Trustee or any agent
of either of them 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
TIA (S) 312, 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 TIA (S) 312(b).

          SECTION 703.  Reports by Trustee.
                        ------------------ 

          Within 60 days after August  15 of each year commencing with the first
August after the first issuance of Notes, the Trustee shall transmit to the
Holders, in the manner and to the extent provided in TIA (S) 313(c), a brief
report dated as of such August 15 if required by TIA (S) 313(a). Delivery of
such reports, information and documents to the Trustee is for informational
purposes only and the Trustee's receipt of such shall not constitute
constructive notice of any information contained therein or determinable from
information contained therein, including the Issuers' compliance with any of its
covenants hereunder (as to which the Trustee is entitled to conclusively rely
exclusively on Officers' Certificates).

          The Trustee also shall comply with TIA (S) 313(b). A copy of each
report at the time of its mailing to Holders shall be filed by the Trustee with
the SEC and each stock exchange (if any) on which the Notes are listed.  The
Issuers agrees to notify promptly the Trustee whenever the Notes become listed
on any stock exchange and of any delisting thereof.

                                       67
<PAGE>
 
                                 ARTICLE EIGHT.
                    MERGER, CONSOLIDATION, OR SALE OF ASSETS

          SECTION 801.  The Issuers and Guarantors May Consolidate Etc. Only on
                        -------------------------------------------------------
Certain Terms.
------------- 

          Neither of the Issuers shall in a single transaction or series of
related transactions consolidate with or merge with or into, or convey all or
substantially all its assets to, another Person, unless:

          (i)   either (A) such Issuer shall be the continuing Person, or (B)
     the Person formed by or surviving any such consolidation or merger (if
     other than such Issuer), or to which any such transfer shall have been made
     (the "Successor Company"), shall be a corporation, limited liability
     company or limited partnership organized and existing under the laws of the
     United States, any State thereof or the District of Columbia;

          (ii)  the Successor Company shall expressly assume, by supplemental
     indenture, executed and delivered to the Trustee, in form satisfactory to
     the Trustee, all the obligations of such Issuer under the Notes and this
     Indenture;

          (iii) immediately after giving effect to such transaction, no Default
     or Event of Default shall have occurred and be continuing;

          (iv)  immediately after giving effect to such transaction, the
     surviving Person would be able to Incur $1.00 of additional Indebtedness
     under the Debt to Operating Cash Flow Ratio contained in the first
     paragraph of Section 1008; and

          (v)   Mediacom shall have delivered to the Trustee prior to the
proposed transaction an Officers' Certificate and an Opinion of Counsel, each
stating that such consolidation, merger or transfer and such supplemental
indenture comply with this Indenture, both in the form required by this
Indenture; provided that in giving such opinion such counsel may rely on such
Officers' Certificate as to any matters of fact (including without limitation as
to compliance with the foregoing clauses (iii) and (iv)).

          No Guarantor will in a single transaction or series of related
consolidate or merge with or into, or transfer all or substantially all of its
assets to, another Person unless:

          (i)   either (A) such Guarantor shall be the continuing Person, or (B)
     the Person formed by or surviving any such consolidation or merger (if
     other than such Guarantor) or to which any such transfer shall have been
     made (a "Successor Guarantor"), is a corporation, limited liability company
     or limited partnership organized and existing under the laws of the United
     States, any State thereof or the District of Columbia;

          (ii)  the Successor Guarantor shall expressly assume by supplemental
     indenture executed and delivered to the Trustee, in form satisfactory to
     the Trustee, all the obligations of such Guarantor under its guarantee of
     the Notes and this Indenture;

          (iii) immediately after giving effect to such transaction, no Default
     or Event of Default shall have occurred and be continuing; and

                                       68
<PAGE>
 
          (iv)  Mediacom shall have delivered to the Trustee prior to the
     proposed transaction an Officers' Certificate, and an Opinion of Counsel,
     each stating that such consolidation, merger or transfer and such
     supplemental indenture comply with this Indenture, both in the form
     required by this Indenture; provided that in giving such opinion such
     counsel may rely on such Officers' Certificate as to any matters of fact
     (including without limitation as to compliance with the foregoing clauses
     (iii) and (iv)).

          SECTION 802.  Successor Substituted.
                        --------------------- 

          Upon any consolidation of the Issuers or the Guarantors with or merger
of the Issuers or the Guarantors with or into any other corporation or any
conveyance, transfer or other disposition of all or substantially all of the
assets of the Issuers or the Guarantors to any Person in accordance with Section
801, the Successor Company or Successor Guarantor will succeed to, and be
substituted for, and may exercise every right and power of, the Issuers or the
Guarantors hereunder and thereafter the predecessor shall be released from all
obligations and covenants hereunder, or under the guarantee of the Notes, as
applicable, but, in the case of conveyance or transfer of all or substantially
all its assets, the predecessor, as applicable, will not be released from the
obligation to pay the principal of and interest on the Notes.


                                 ARTICLE NINE.
            SUPPLEMENTS, AMENDMENTS AND MODIFICATIONS TO INDENTURE

          SECTION 901.  Supplemental Indentures Without Consent of Holders.
                        -------------------------------------------------- 

          Without the consent of any Holders, the Issuers, the Guarantors and
the Trustee, at any time and from time to time, may enter into one or more
indentures supplemental hereto, in form satisfactory to the Trustee, for any of
the following purposes:

          (i)    to cure any ambiguity, omission, defect or inconsistency; or

          (ii)   to provide for uncertificated Notes in addition to or in place
     of certificated Notes (provided that the uncertificated Notes are issued in
     registered form for purposes of Section 163(f) of the Code, or in a manner
     such that the uncertificated Notes are described in Section 163(f)(2)(B) of
     the Code); or

          (iii)  to add Restricted Subsidiary Guarantees with respect to the
Notes; or

          (iv)   to release Guarantors pursuant to Section 1017; or

          (v)    to provide for the assumption by a successor corporation,
     limited liability company or limited partnership of the obligations of the
     Issuers or any Guarantor hereunder; or

          (vi)   to secure the Notes; or

          (vii)  to add to the covenants of the Issuers for the benefit of the
     Holders or to surrender any right or power conferred upon the Issuers; or

          (viii) to make any other change that does not adversely affect the
     rights of any Holder; or

                                       69
<PAGE>
 
          (ix)   to comply with any requirement of the SEC in connection with
     the qualification of this Indenture under the Trust Indenture Act.

          SECTION 902.  Supplemental Indentures with Consent of Holders.
                        ----------------------------------------------- 

          With the consent of the Holders of at least a majority in aggregate
principal amount of the then outstanding Notes (including consents obtained in
connection with a tender offer or exchange offer for the Notes), the Issuers,
the Guarantors and the Trustee may enter into an indenture or 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 under this Indenture;
provided, however, that no such supplemental indenture shall, without the
consent of the Holder of each outstanding Note affected thereby (with respect to
any Notes held by a nonconsenting Holder of the Notes):

          (i)   change or extend the fixed maturity of any Notes, reduce the
rate or extend the time of payment of interest or Liquidated Damages thereon,
reduce the principal amount thereof or premium, if any, thereon or change the
currency in which the Notes are payable; or

          (ii)  reduce the premium payable upon any redemption of Notes in
accordance with the optional redemption provisions of the Notes and Section 1101
or change the time before which the Notes may be redeemed; or

          (iii) waive a default in the payment of principal or interest or
Liquidated Damages on the Notes (except that holders of a majority in aggregate
principal amount of the Notes at the time outstanding may (a) rescind an
acceleration of the Notes that resulted from a non-payment default and (b) waive
the payment default that resulted from such acceleration) or alter the rights of
Noteholders to waive defaults; or

          (iv)  reduce the aforesaid percentage of Notes, the consent of the
holders of which is required for any such modification; or

          (v)   modify the Restricted Subsidiary Guarantees or Article Thirteen
(except as contemplated by the terms of this Indenture) in any manner adverse to
the Holders.

          Any existing Event of Default, other than a default in the payment of
principal or interest or Liquidated Damages on the Notes, or compliance with any
provision of the Notes or this Indenture, other than any provision related to
the payment of principal or interest or Liquidated Damages on the Notes, may be
waived with the consent of holders of at least a majority in aggregate principal
amount of the Notes at the time outstanding.  The consent of the Holders is not
necessary under this Indenture to approve the particular form of any proposed
amendment or supplemental indenture. It is sufficient if such consent approves
the substance of the proposed amendment or supplemental indenture.

          SECTION 903.  Execution of Supplemental Indentures.
                        ------------------------------------ 

          The Trustee may, but shall not be obligated to, enter into any such
supplemental indenture which affects the Trustee's own rights, duties or
immunities, as determined by the Trustee in its sole discretion under this
Indenture or otherwise. In signing or refusing to sign any supplemental
indenture permitted by this Article or the modifications thereby of the trusts
created by this Indenture, the Trustee shall be entitled to receive, and shall
be fully protected in relying upon, an Officers' Certificate and an Opinion of
Counsel stating that the execution of such supplemental indenture is authorized
or permitted by this Indenture.

                                       70
<PAGE>
 
          SECTION 904.  Effect of Supplemental Indentures.
                        --------------------------------- 

          Upon the execution of any supplemental indenture under this Article,
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 (except as provided in Section 902).

          SECTION 905.  Conformity with Trust Indenture Act.
                        ----------------------------------- 

          Every supplemental indenture executed pursuant to the Article shall
conform to the requirements of the Trust Indenture Act as then in effect.

          SECTION 906.  Reference in Notes to Supplemental Indentures.
                        --------------------------------------------- 

          Notes authenticated and delivered after the execution of any
supplemental indenture pursuant to this Article may, and shall if required by
the Trustee, bear a notation in form approved by the Trustee as to any matter
provided for in such supplemental indenture. If the Issuers or the Trustee shall
so determine, new Notes so modified as to conform to any such supplemental
indenture may be prepared and executed by the Issuers, and the Issuers shall
issue and the Trustee shall authenticate a new Note that reflects the changed
terms, the cost and expense of which will be borne by the Issuers in exchange
for outstanding Notes.

          SECTION 907.  Notice of Supplemental Indentures.
                        --------------------------------- 

          Promptly after the execution by the Issuers and the Trustee of any
supplemental indenture pursuant to the provisions of Section 902, the Issuers
shall give notice thereof to the Holders of each outstanding Note affected, in
the manner provided for in Section 106, setting forth in general terms the
substance of such supplemental indenture. The failure to give such notice to all
the Holders, or any defect therein, will not impair or affect the validity of
the supplemental indenture.


                                  ARTICLE TEN.
                                   COVENANTS

          SECTION 1001.  Payment of Principal, Premium, if any, and Interest.
                         --------------------------------------------------- 

          The Issuers, as joint and several obligors, covenant and agree for the
benefit of the Holders that they will duly and punctually pay the principal of
(and premium, if any) and interest and Liquidated Damages, if any, on the Notes
in accordance with the terms of the Notes and this Indenture.

          SECTION 1002.  Maintenance of Office or Agency.
                         ------------------------------- 

          The Issuers will maintain in the Borough of Manhattan, The City of New
York, an office or agency where the Notes may be presented or surrendered for
payment, where, if applicable, the Notes may be surrendered for registration of
transfer or exchange and where notices and demands to or upon the Issuers in
respect of the Notes and this Indenture may be served. The corporate trust
office of the Trustee at 88 Pine Street, New York, New York 10005 shall be such
office or agency of the Issuers, unless the Issuers shall designate and maintain
some other office or agency for one or more of such purposes. The Issuers will
give prompt written notice to the Trustee of any change in the location of any
such office or agency. If at any time the Issuers shall fail to maintain any
such required office or agency or shall fail to

                                       71
<PAGE>
 
furnish the Trustee with the address thereof, such presentations, surrenders,
notices and demands may be made or served at the Corporate Trust Office, and the
Issuers hereby appoint the Trustee as their agent to receive all such
presentations, surrenders, notices and demands.

          The Issuers 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 such purposes and may from time to
time rescind any such designation; provided, however, that no such designation
or rescission shall in any manner relieve the Issuers of its obligation to
maintain an office or agency in The City of New York for such purposes. The
Issuers will give prompt written notice to the Trustee of any such designation
or rescission and any change in the location of any such other office or agency.

          SECTION 1003.  Money for Note Payments to Be Held in Trust.
                         ------------------------------------------- 

          If the Issuers shall at any time act as their own Paying Agent, they
will, on or before each due date of the principal of (or premium, if any) or
interest on any of the Notes, segregate and hold in trust for the benefit of the
Persons entitled thereto a sum sufficient to pay the principal of (or premium,
if any) or interest so becoming due until such sums shall be paid to such
Persons or otherwise disposed of as herein provided and will promptly notify the
Trustee of its action or failure to so act.

          Whenever the Issuers shall have one or more Paying Agents for the
Notes, they will, on or before each due date of the principal of (or premium, if
any) or interest on any Notes, deposit with a Paying Agent a sum in same day
funds (or New York Clearing House funds if such deposit is made prior to the
date on which such deposit is required to be made) that shall be available to
the Trustee by 10:00 a.m. Eastern Standard Time on such due date sufficient to
pay the principal (and premium and Liquidated Damages, if any) or interest so
becoming due, such sum 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 Issuers will promptly notify the Trustee of such action or
any failure to so act.

          The Issuers will cause each Paying Agent (other than the Trustee) to
execute and deliver to the Trustee an instrument in which such Paying Agent
shall agree with the Trustee, subject to the provisions of this Section, that
such Paying Agent will:

          (i)   hold all sums held by it for the payment of the principal of
     (and premium or Liquidated Damages, if any) or interest on Notes in trust
     for the benefit of the Persons entitled thereto until such sums shall be
     paid to such Persons or otherwise disposed of as herein provided;

          (ii)  give the Trustee notice of any default by the Issuers (or any
     other obligor upon the Notes) in the making of any payment of principal
     (and premium or Liquidated Damages, if any) or interest; and

          (iii) at any time during the continuance of any such default, upon
     the written request of the Trustee, forthwith pay to the Trustee all sums
     so held in trust by such Paying Agent.

          The Issuers may at any time, for the purpose of obtaining the
satisfaction and discharge of this Indenture or for any other purpose, pay, or
by Authentication Order direct any Paying Agent to pay, to the Trustee all sums
held in trust by the Issuers or such Paying Agent, such sums to be held by the
Trustee upon the same trusts as those upon which such sums were held by the
Issuers or such Paying Agent; and, upon such payment by any Paying Agent to the
Trustee, such Paying Agent shall be released from all further liability with
respect to such sums.

                                       72
<PAGE>
 
          Any money deposited with the Trustee or any Paying Agent, or then held
by the Issuers, in trust for the payment of the principal of (or premium or
Liquidated Damages, if any) or interest on any Note and remaining unclaimed for
two years after such principal, premium, Liquidated Damages or interest has
become due and payable shall be paid to the Issuers on the Issuers' Request, or
(if then held by the Issuers) shall be discharged from such trust; and the
Holder of such Note shall thereafter, as an unsecured general creditor, look
only to the Issuers for payment thereof, and all liability of the Trustee or
such Paying Agent with respect to such trust money, and all liability of the
Issuers as trustee thereof, shall thereupon cease; provided, however, that the
Trustee or such Paying Agent, before being required to make any such repayment
to the Issuers, may at the expense of the Issuers cause to be published once, in
a leading daily newspaper (if practicable, The Wall Street Journal (Eastern
Edition)) printed in the English language and of general circulation in New York
City, notice that such money remains unclaimed and that, after a date specified
therein, which shall not be less than 30 days from the date of such publication,
any unclaimed balance of such money then remaining will be repaid to the
Issuers.

          SECTION 1004.  Corporate Existence.
                         ------------------- 

          Subject to Article Eight, the Issuers will do or cause to be done all
things necessary to preserve and keep in full force and effect the corporate
existence and that of each Restricted Subsidiary and the corporate rights
(charter and statutory) licenses and franchises of the Issuers and each
Restricted Subsidiary; provided, however, that the Issuers shall not be required
to preserve any such existence (except the Issuers) right, license or franchise
if the Executive Committee of Mediacom shall determine that the preservation
thereof is no longer desirable in the conduct of the business of the Issuers and
each of Mediacom's Restricted Subsidiaries, taken as a whole, and that the loss
thereof is not, and will not be, disadvantageous in any material respect to the
Holders.

          SECTION 1005.  Payment of Taxes and Other Claims.
                         --------------------------------- 

          The Issuers will pay or discharge or cause to be paid or discharged,
before the same shall become delinquent, (i) all material taxes, assessments and
governmental charges levied or imposed upon the Issuers or any Subsidiary or
upon the income, profits or property of the Issuers or any Subsidiary and (ii)
all lawful claims for labor, materials and supplies, which, if unpaid, might by
law become a material liability or lien upon the property of the Issuers or any
Restricted Subsidiary; provided, however, that the Issuers 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 and for which appropriate reserves, if
necessary (in the good faith judgment of management of the Issuers) are being
maintained in accordance with GAAP.

          SECTION 1006.  Compliance with Laws.
                         -------------------- 

          The Issuers shall comply, and shall cause each of its Restricted
Subsidiaries to comply, with all applicable statutes, rules, regulations, orders
and restrictions of the United States of America, all states and municipalities
thereof, and of any governmental regulatory authority, in respect of the conduct
of their respective businesses and the ownership of their respective properties,
except for such noncompliances as would not in the aggregate have a material
adverse effect on the financial condition or results of operations of the
Issuers and its Restricted Subsidiaries, taken as a whole.

                                       73
<PAGE>
 
          SECTION 1007.  Limitation on Restricted Payments.
                         --------------------------------- 

          (a) So long as any of the Notes remain outstanding, Mediacom shall
not, and shall not permit any Restricted Subsidiary to, make any Restricted
Payment if (i) at the time of such proposed Restricted Payment, a Default or
Event of Default shall have occurred and be continuing or shall occur as a
consequence of such Restricted Payment; (ii) immediately after giving effect to
such proposed Restricted Payment, Mediacom would not be able to Incur $1.00 of
additional Indebtedness under the Debt to Operating Cash Flow Ratio of the first
paragraph of Section 1008, or (iii) immediately after giving effect to any such
Restricted Payment, the aggregate of all Restricted Payments which shall have
been made on or after the date hereof (the amount of any Restricted Payment, if
other than cash, to be based upon the fair market value thereof on the date of
such Restricted Payment (without giving effect to subsequent changes in value)
as determined in good faith by the Executive Committee, whose determination
shall be conclusive and evidenced by a Committee Resolution) would exceed an
amount equal to the difference between (a) the Cumulative Credit and (b) 1.4
times Cumulative Interest Expense.

          (b) The provisions of paragraph (a) of this Section 1007 shall not
prevent (i) the retirement of any of Mediacom's Equity Interests in exchange
for, or out of the proceeds of, the substantially concurrent sale (other than to
a Subsidiary of Mediacom or an employee stock ownership plan or to a trust
established by Mediacom or any Subsidiary of Mediacom for the benefit of its
employees) of Equity Interests of Mediacom; (ii) the payment of any dividend or
distribution on, or redemption of Equity Interests within 60 days after the date
of declaration of such dividend or distribution or the giving of formal notice
of such redemption, if at the date of such declaration or giving of such formal
notice such payment or redemption would comply with the provisions of this
Indenture; (iii) Investments constituting Restricted Payments made as a result
of the receipt of non-cash consideration from any Asset Sale made pursuant to
and in compliance with the provisions described under Section 1013; (iv)
payments of compensation to officers, directors and employees of Mediacom or any
Restricted Subsidiary so long as the Executive Committee or the manager of
Mediacom in good faith shall have approved the terms thereof; (v) the payment of
dividends on any Equity Interests of any Restricted Subsidiary following the
issuance thereof in an amount per annum of up to 6% of the net proceeds received
by Mediacom or such Restricted Subsidiary from an Equity Offering of such Equity
Interests; (vi) the payment of management, consulting and advisory fees, and any
related reimbursement of expenses or indemnity, to Mediacom Management or any
Affiliate thereof and other amounts payable pursuant to the Operating Agreement,
other than any dividend or distribution (whether made in cash, property or
securities) on or with respect to any Equity Interests of Mediacom or any
redemption, repurchase, retirement or other direct or indirect acquisition of
any Equity Interests of Mediacom, or any warrants, rights or options to purchase
or acquire any such Equity Interests or any securities exchangeable for or
convertible into any such Equity Interests; (vii) the payment of amounts in
connection with any merger, consolidation, or sale of assets effected in
accordance with Article Eight, provided that no such payment may be made
pursuant to this clause (vii) unless, after giving effect to such transaction
(and the Incurrence of any Indebtedness in connection therewith and the use of
the proceeds thereof), Mediacom would be able to Incur $1.00 of additional
Indebtedness in compliance with the first paragraph of Section 1008 such that
after incurring that $1.00 of additional Indebtedness, the Debt to Operating
Cash Flow Ratio would be less than or equal to 6.0 to 1.0; (viii) the
retirement, redemption or repurchase (a "Regulatory Equity Interest Repurchase")
of any of Mediacom's Equity Interests pursuant to Article 11 of the Operating
Agreement as a result of the occurrence of a Triggering Event (as defined in the
Operating Agreement and which relates to certain small business investment
company, Federal Communications Commission and other regulatory violations
described therein); (ix) the redemption, repurchase, retirement, defeasance or
other acquisition of any Subordinated Obligations in exchange for, or out of net
cash proceeds of the substantially concurrent sale (other than to a Subsidiary
of Mediacom or an employee stock ownership plan or to a trust established by
Mediacom or any Subsidiary of Mediacom (for the benefit of its employees) of
Equity Interests of Mediacom or Subordinated Obligations of

                                       74
<PAGE>
 
Mediacom; (x) the payment of any dividend or distribution on or with respect to
any Equity Interests of any Restricted Subsidiary to the holders of its Equity
Interests on a pro rata basis; (xi) the making and consummation of (A) an Excess
Proceeds Offer in accordance with the provisions of this Indenture with any
Excess Proceeds or (B) a Change of Control Offer with respect to the Notes in
accordance with the provisions of this Indenture or (C) any offer similar to the
offer described in clause (A) or (B) set forth in any other indenture governing
debt securities; (xii) during the period Mediacom is treated as a partnership
for U.S. federal income tax purposes and after such period to the extent
relating to the liability for such period, the payment of distributions in
respect of members' or partners' income tax liability with respect to Mediacom
in an amount not to exceed the aggregate amount of tax distributions, if any,
permitted to be made by Mediacom to its members under the Operating Agreement
(such amount not to include amounts in respect of taxes resulting from
Mediacom's reorganization as or change in the status to a corporation); (xiii)
the payment by any Restricted Subsidiary to Mediacom or another Restricted
Subsidiary of principal and interest due in respect of intercompany Indebtedness
and dividends and other distributions in respect of Preferred Equity Interests
in such Restricted Subsidiary; (xiv) the payment by Mediacom California of all
amounts due in respect of the promissory note in the original principal amount
of $2,800,000 issued to Booth American Company; and (xv) the distribution of any
Investment originally made by Mediacom or any Restricted Subsidiary pursuant to
the first paragraph of this covenant to holders of Equity Interests of Mediacom
or such Restricted Subsidiary, as the case may be; provided, however, that in
the case of clauses (ii), (v), (vii), (x), (xi) and (xv) of this paragraph, no
Default or Event of Default shall have occurred and be continuing at the time of
such Restricted Payment or as a result thereof. In determining the aggregate
amount of Restricted Payments made on or after the date of this Indenture,
Restricted Payments made pursuant to clauses (ii) and (v) and any Restricted
Payment deemed to have been made pursuant to Section 1009 shall be included in
such calculation.

          (c) Not later than the date of making any Restricted Payment, Mediacom
shall deliver to the Trustee an Officers' Certificate stating that such
Restricted Payment is permitted and setting forth the basis upon which the
calculations required by this Section 1007 were computed, which calculations may
be based upon Mediacom's latest available financial statements. The Trustee
shall have no duty to recompute or recalculate or verify the accuracy of the
information set forth in such Officers' Certificate.

          SECTION 1008.  Limitation on Indebtedness.
                         -------------------------- 

          Mediacom shall not, and shall not permit any Restricted Subsidiary to,
directly or indirectly, Incur any Indebtedness (including Acquired Indebtedness)
or issue any Disqualified Equity Interests except for Permitted Indebtedness;
provided, however, that Mediacom or any Restricted Subsidiary may Incur
Indebtedness or issue Disqualified Equity Interests if, at the time of and
immediately after giving pro forma effect to such Incurrence of Indebtedness or
issuance of Disqualified Equity Interests and the application of the proceeds
therefrom, the Debt to Operating Cash Flow Ratio would be less than or equal to
7.0 to 1.0.

          The limitations contained in the foregoing paragraph shall not apply
to the Incurrence of any of the following (collectively, "Permitted
Indebtedness"), each of which shall be given independent effect:

          (a) Indebtedness under the Initial Notes issued on the date of this
     Indenture, the Exchange Notes issued in exchange for the Initial Notes, the
     Private Exchange Notes issued in exchange for the Initial Notes and this
     Indenture;

                                       75
<PAGE>
 
          (b)  Indebtedness and Disqualified Equity Interests of Mediacom and 
     the Restricted Subsidiaries outstanding on the Issue Date other than
     Indebtedness described in clause (a), (c), (d) or (f) of this paragraph;

          (c)  (i) Indebtedness of the Restricted Subsidiaries under the
     Subsidiary Credit Facilities (including any refinancing thereof), and (ii)
     Indebtedness of the Restricted Subsidiaries (including any refinancing
     thereof) if, at the time of and immediately after giving pro forma effect
     to the Incurrence of such Indebtedness and the application of the proceeds
     therefrom, the Debt to Operating Cash Flow Ratio would be less than or
     equal to 6.0 to 1.0; provided, however, that for purposes of the
     calculation of such Ratio, the term "Consolidated Total Indebtedness" shall
     refer only to the Consolidated Total Indebtedness of the Restricted
     Subsidiaries (including Indebtedness Incurred under the Subsidiary Credit
     Facilities and the Future Subsidiary Credit Facilities) outstanding as of
     the Determination Date (as defined hereafter in the term "Debt to Operating
     Cash Flow Ratio") and the term "Operating Cash Flow" shall refer only to
     the Subsidiary Operating Cash Flow of the Restricted Subsidiaries for the
     related Measurement Period (as defined in the term "Debt to Operating Cash
     Flow Ratio");

          (d)  Indebtedness and Disqualified Equity Interests of (x) any
     Restricted Subsidiary owed to or issued to and held by Mediacom or any
     Restricted Subsidiary and (y) Mediacom owed to and held by any Restricted
     Subsidiary which is unsecured and subordinated in right of payment to the
     payment and performance of the Issuers' obligations under this Indenture
     and the Notes; provided, however, that an Incurrence of Indebtedness and
     Disqualified Equity Interests that is not permitted by this clause (d)
     shall be deemed to have occurred upon (i) any sale or other disposition of
     any Indebtedness or Disqualified Equity Interests of Mediacom or a
     Restricted Subsidiary referred to in this clause (d) to any Person (other
     than Mediacom or a Restricted Subsidiary), (ii) any sale or other
     disposition of Equity Interests of a Restricted Subsidiary which holds
     Indebtedness or Disqualified Equity Interests of Mediacom or another
     Restricted Subsidiary such that such Restricted Subsidiary ceases to be a
     Restricted Subsidiary or (iii) any designation of a Restricted Subsidiary
     which holds Indebtedness or Disqualified Equity Interests of Mediacom as an
     Unrestricted Subsidiary;

          (e)  guarantees by any Restricted Subsidiary of Indebtedness of
     Mediacom or any other Restricted Subsidiary Incurred in accordance with the
     provisions of this Indenture;
        
          (f)  Hedging Agreements of Mediacom or any Restricted Subsidiary
     relating to any Indebtedness of Mediacom or such Restricted Subsidiary, as
     the case may be, Incurred in accordance with the provisions of this
     Indenture; provided that such Hedging Agreements have been entered into for
     bona fide business purposes and not for speculation;

          (g)  Indebtedness or Disqualified Equity Interests of Mediacom or any
     Restricted Subsidiary to the extent representing a replacement, renewal,
     refinancing or extension (collectively, a "refinancing") of outstanding
     Indebtedness or Disqualified Equity Interests of Mediacom or any Restricted
     Subsidiary, as the case may be, Incurred in compliance with the Debt to
     Operating Cash Flow Ratio of the first paragraph of this covenant or clause
     (a) or (b) of this paragraph of this covenant; provided, however, that (i)
     Indebtedness or Disqualified Equity Interests of Mediacom may not be
     refinanced under this clause (g) with Indebtedness or Disqualified Equity
     Interests of any Restricted Subsidiary, (ii) any such refinancing shall not
     exceed the sum of the principal amount or liquidation preference or
     redemption payment value (or, if such Indebtedness or Disqualified Equity
     Interests provides for a lesser amount to be due and payable upon a
     declaration of acceleration thereof at the time of such refinancing, an
     amount no greater than such lesser amount) of the Indebtedness or
     Disqualified Equity Interests being

                                       76
<PAGE>
 
     refinanced plus the amount of accrued interest or dividends thereon and the
     amount of any reasonably determined prepayment premium necessary to
     accomplish such refinancing and such reasonable fees and expenses incurred
     in connection therewith, (iii) Indebtedness representing a refinancing of
     Indebtedness of Mediacom shall have a Weighted Average Life to Maturity
     equal to or greater than the Weighted Average Life to Maturity of the
     Indebtedness being refinanced, (iv) Subordinated Obligations of Mediacom or
     Disqualified Equity Interests of Mediacom may only be refinanced with
     Subordinated Obligations of Mediacom or Disqualified Equity Interests of
     Mediacom, and (v) Other Pari Passu Debt which is unsecured may only be
     refinanced with unsecured Indebtedness, which is either Other Pari Passu
     Debt or Subordinated Obligations, or with Disqualified Equity Interests;

          (h)  Indebtedness of Mediacom or a Restricted Subsidiary Incurred as a
     result of the pledge by Mediacom or such Restricted Subsidiary of
     intercompany indebtedness or Equity Interests in another Restricted
     Subsidiary or Equity Interests in an Unrestricted Subsidiary in the
     circumstance where recourse to Mediacom or such Restricted Subsidiary is
     limited to the value of the intercompany Indebtedness or the Equity
     Interests so pledged;
        
          (i)  Indebtedness of Mediacom or a Restricted Subsidiary represented
     by Capitalized Lease Obligations, mortgage financings, purchase money
     obligations or letters of credit, in each case Incurred for the purpose of
     financing all or any part of the purchase price or cost of construction or
     improvement of property, plant or equipment used in the business of
     Mediacom or such Restricted Subsidiary or a Related Business in an
     aggregate principal amount not to exceed $15,000,000 at any time
     outstanding;

          (j)  Indebtedness of Mediacom Incurred to finance (including any
     refinancing thereof) one or more Regulatory Equity Interest Repurchases
     occurring in accordance with and pursuant to the Operating Agreement; and

          (k)  Indebtedness of Mediacom or a Restricted Subsidiary in an
     aggregate amount not to exceed two times the sum of (i) the aggregate Net
     Cash Proceeds to Mediacom from (x) the issuance (other than to a Subsidiary
     of Mediacom or an employee stock ownership plan or a trust established by
     Mediacom or any Subsidiary of Mediacom (for the benefit of its employees))
     of any class of Equity Interests of Mediacom (other than Disqualified
     Equity Interests) on or after the date of this Indenture or (y)
     contributions to the equity capital of Mediacom on or after the date of
     this Indenture which do not themselves constitute Disqualified Equity
     Interests and (ii) the fair market value, as determined by an independent
     nationally recognized accounting, appraisal or investment banking firm
     experienced in similar types of transactions, of any assets (other than
     cash or Cash Equivalents) that are used or useful in a Related Business or
     Equity Interests of a Person engaged in a Related Business that is or
     becomes a Restricted Subsidiary of Mediacom, in each case received by
     Mediacom after the date of this Indenture in exchange for the issuance
     (other than to a Subsidiary of Mediacom) of its Equity Interests (other
     than Disqualified Equity Interests); provided, that (A) the amount of such
     Net Cash Proceeds with respect to which Indebtedness is incurred pursuant
     to this clause (k) shall not be deemed Net Cash Proceeds from the issue or
     sale of Equity Interests for purposes of clause (ii) of the definition of
     "Cumulative Credit" and (B) the issuance of Equity Interests with respect
     to which Indebtedness is incurred pursuant to this clause (k) shall not
     also be used to effect a Restricted Payment pursuant to clauses (i) or (ix)
     of Section 1007(b); and

          (l)  In addition to any Indebtedness described in clauses (a) through
     (k) above, Indebtedness of Mediacom or any of the Restricted Subsidiaries
     so long as the aggregate principal

                                       77
<PAGE>
 
     amount of all such Indebtedness incurred pursuant to this clause (l) does
     not exceed $10,000,000 at any one time outstanding.

          For purposes of determining compliance with this Section 1008, in the
event that an item of Indebtedness meets the criteria of more than one of the
categories of Permitted Indebtedness described in clauses (a) through (l) above
or is entitled to be incurred pursuant to the first paragraph of this Section
1008, Mediacom shall, in its sole discretion, classify such item of Indebtedness
in any manner that complies with this Section 1008 and such item of Indebtedness
shall be treated as having been incurred pursuant to only one of such clauses or
pursuant to the first paragraph hereof.

          SECTION 1009.  Limitation on Affiliate Transactions.
                         ------------------------------------ 

          Mediacom shall not, and shall not permit any Restricted Subsidiary to,
directly or indirectly, engage in any transaction (or series of related
transactions) involving in the aggregate $5,000,000 or more with any Affiliate
unless such transaction (or series of related transactions) shall have been
approved pursuant to a Committee Resolution rendered in good faith by the
Executive Committee or, if applicable, a committee comprising the independent
members of the Executive Committee, which approval in each case shall be
conclusive, to the effect that such transaction (or series of related
transactions) is (a) in the best interest of Mediacom or such Restricted
Subsidiary and (b) upon terms which would be obtainable by Mediacom or a
Restricted Subsidiary in a comparable arm's-length transaction with a Person
which is not an Affiliate, except that the foregoing shall not apply in the case
of any of the following transactions (the "Specified Affiliate Transactions"):
(i) the making of any Restricted Payment (including the making of any Permitted
Investment that is permitted pursuant to Section 1007); (ii) any transaction or
series of transactions between Mediacom and one or more Restricted Subsidiaries
or between two or more Restricted Subsidiaries; (iii) the payment of
compensation (including, without limitation, amounts paid pursuant to employee
benefit plans) for the personal services of, and indemnity provided on behalf
of, officers, members, directors and employees of Mediacom or any Restricted
Subsidiary, and management, consulting or advisory fees and reimbursements of
expenses and indemnity in each case so long as the Executive Committee in good
faith shall have approved the terms thereof and deemed the services theretofore
or thereafter to be performed for such compensation or fees to be fair
consideration therefor; (iv) any payments for goods or services purchased in the
ordinary course of business, upon terms which would be obtainable by Mediacom or
a Restricted Subsidiary in a comparable arm's-length transaction with a Person
which is not an Affiliate; and (v) any transaction pursuant to any agreement
with any Affiliate in effect on the date of this Indenture (including, but not
limited to, the Operating Agreement and other agreements relating to the payment
of management fees, acquisition fees and expense reimbursements), including any
amendments thereto entered into after the date of this Indenture, provided, that
the terms of any such amendment are not less favorable to Mediacom than the
terms of the relevant agreement in effect prior to any such amendment, as
determined in good faith by the Executive Committee. Except in the case of a
Specified Affiliate Transaction, Mediacom shall not, and shall not permit any
Restricted Subsidiary, directly or indirectly, to engage in any transaction (or
series of related transactions) involving in the aggregate $25,000,000 or more
with any Affiliate unless (i) such transaction (or series of related
transactions) shall have been approved pursuant to a Committee Resolution
rendered in good faith by the Executive Committee or, if applicable, a committee
comprising the independent members of the Executive Committee to the effect set
forth in clauses (a) and (b) above; and (ii) Mediacom shall have received an
opinion from an independent nationally recognized accounting, appraisal or
investment banking firm experienced in the review of similar types of
transactions stating that the terms of such transaction (or series of related
transactions) are fair to Mediacom or such Restricted Subsidiary, as the case
may be, from a financial point of view. Notwithstanding the foregoing, any
transaction (or series of related transactions) entered into by Mediacom or any
Restricted Subsidiary with any Affiliate without complying with the foregoing
provisions of this Section 1009 shall not constitute a violation of the
provisions of this Section 1009 if Mediacom or such Restricted Subsidiary

                                       78
<PAGE>
 
would be permitted to make a Restricted Payment pursuant to paragraph (a) of
Section 1007 at the time of the completion of such transaction (or series of
related transactions) in an amount equal to the fair market value of such
transaction (or series of related transactions), as determined in good faith by
the Executive Committee, whose determination shall be conclusive and evidenced
by a Committee Resolution. In such a case, Mediacom or such Restricted
Subsidiary, as the case may be, shall be deemed to have made a Restricted
Payment for purposes of the calculation of Restricted Payments pursuant to
clause (iii) of paragraph (a) of Section 1007.

          SECTION 1010.  Limitation on Dividends and Other Payment Restrictions
                         ------------------------------------------------------
Affecting Subsidiaries.
---------------------- 

          Mediacom shall not, and shall not permit any Restricted Subsidiary to,
directly or indirectly, create or otherwise cause or suffer to exist or become
effective any consensual encumbrance or restriction of any kind on the ability
of any Restricted Subsidiary to (a) pay dividends or make any other
distributions to Mediacom or any Restricted Subsidiary on its Equity Interests;
(b) pay any Indebtedness owed to Mediacom or any Restricted Subsidiary; (c) make
loans or advances, or guarantee any such loans or advances, to Mediacom or any
Restricted Subsidiary; (d) transfer any of its properties or assets to Mediacom
or any Restricted Subsidiary; (e) grant Liens on the assets of Mediacom or any
Restricted Subsidiary in favor of the holders of the Notes; or (f) guarantee the
Notes or any renewals or refinancings thereof (any of the actions described in
clauses (a) through (f) above is referred to herein as a "Specified Action"),
except for (i) such encumbrances or restrictions arising by reason of Acquired
Indebtedness of any Restricted Subsidiary existing at the time such Person
became a Restricted Subsidiary, provided that such encumbrances or restrictions
were not created in anticipation of such Person becoming a Restricted Subsidiary
and are not applicable to Mediacom or any other Restricted Subsidiary, (ii) such
encumbrances or restrictions arising under refinancing Indebtedness permitted by
clause (g) of the second paragraph under Section 1008; provided that the terms
and conditions of any such restrictions are no less favorable to the holders of
Notes than those under the Indebtedness being refinanced, (iii) customary
provisions restricting the assignment of any contract or interest of Mediacom or
any Restricted Subsidiary, (iv) restrictions contained in this Indenture or any
other indenture governing debt securities that are no more restrictive than
those contained in this Indenture, and (v) restrictions under the Subsidiary
Credit Facilities and under the Future Subsidiary Credit Facilities, provided
that, in the case of any Future Subsidiary Credit Facility Mediacom shall have
used commercially reasonable efforts to include in the agreements relating to
such Future Subsidiary Credit Facility provisions concerning the encumbrance or
restriction on the ability of any Restricted Subsidiary to take any Specified
Action that are no more restrictive than those in effect in the Subsidiary
Credit Facilities on the date of the creation of the applicable restriction in
such Future Subsidiary Credit Facility ("Comparable Restriction Provisions"),
and provided further that if Mediacom shall conclude in its sole discretion
based on then prevailing market conditions that it is not in the best interest
of Mediacom and the Restricted Subsidiaries to comply with the foregoing
proviso, the failure to include Comparable Restriction Provisions in the
agreements relating to such Future Subsidiary Credit Facility shall not
constitute a violation of the provisions of this Section 1010.

          SECTION 1011.  Limitation on Liens.
                         ------------------- 

          Mediacom shall not Incur any Indebtedness secured by a Lien against or
on any of its property or assets now owned or hereafter acquired by Mediacom
unless contemporaneously therewith effective provision is made to secure the
Notes equally and ratably with such secured Indebtedness. This restriction does
not, however, apply to Indebtedness secured by (i) Liens, if any, in effect on
the date of this Indenture; (ii) Liens in favor of governmental bodies to secure
progress or advance payments; (iii) Liens on Equity Interests or Indebtedness
existing at the time of the acquisition thereof (including acquisition through
merger or consolidation), provided that such Liens were not Incurred in
anticipation

                                       79
<PAGE>
 
of such acquisition; (iv) Liens securing industrial revenue or pollution control
bonds; (v) Liens securing the Notes; (vi) Liens securing Indebtedness of
Mediacom in an amount not to exceed $10,000,000 at any time outstanding; (vii)
Other Permitted Liens; and (viii) any extension, renewal or replacement of any
Lien referred to in the foregoing clauses (i) through (vii), inclusive.

          SECTION 1012.  Change of Control.
                         ----------------- 

          (a) Upon the occurrence of a Change of Control, each holder of Notes
shall have the right to require the Issuers to repurchase all or any part of
such holder's Notes pursuant to an offer described in this Section 1012 (the
"Change of Control Offer") at a purchase price equal to 101% of the principal
amount thereof plus any accrued and unpaid interest and Liquidated Damages, if
any, thereon to the date of repurchase (the "Change of Control Payment").

          (b) Within 30 days of the occurrence of a Change of Control, the
Issuers shall send by first-class mail, postage prepaid, to the Trustee and to
each holder of the Notes, at the address appearing in the Note Register, a
notice stating: (1) that the Change of Control Offer is being made pursuant to
this Section 1012 and that all Notes tendered will be accepted for payment; (2)
the purchase price and the purchase date, which shall be a business day no
earlier than 30 days nor later than 60 days from the date such notice is mailed
(the "Change of Control Payment Date"); (3) that any Note not tendered will
continue to accrue interest; (4) that, unless the Issuers default in the payment
of the Change of Control Payment, any Notes accepted for payment pursuant to the
Change of Control Offer shall cease to accrue interest after the Change of
Control Payment Date; (5) that holders accepting the offer to have their Notes
purchased pursuant to a Change of Control Offer will be required to surrender
the Notes to the Paying Agent at the address specified in the notice prior to
the close of business on the business day preceding the Change of Control
Payment Date; (6) that holders will be entitled to withdraw their acceptance if
the Paying Agent receives, not later than the close of business on the third
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 the Notes delivered for purchase, and a statement that such
holder is withdrawing its election to have such Notes purchased; (7) that
holders whose Notes are being purchased only in part will be issued new Notes
equal in principal amount to the unpurchased portion of the Notes surrendered,
provided that each Note purchased and each such new Note issued shall be in an
original principal amount in denominations of $1,000 and integral multiples
thereof; (8) any other procedures that a holder must follow to accept a Change
of Control Offer or effect withdrawal of such acceptance; and (9) the name and
address of the Paying Agent.

          (c) On the Change of Control Payment Date, the Issuers shall, to the
extent lawful (i) accept for payment Notes or portions thereof tendered pursuant
to the Change of Control Offer, (ii) deposit with the Paying Agent money
sufficient to pay the purchase price of all Notes or portions thereof so
tendered and (iii) deliver or cause to be delivered to the Trustee Notes so
accepted together with an Officers' Certificate stating the Notes or portions
thereof tendered to the Issuers. The Paying Agent shall promptly mail to each
holder of Notes so accepted payment in an amount equal to the purchase price for
such Notes, and the Issuers shall execute and issue, and the Trustee shall
promptly authenticate and mail to such holder, a new Note equal in principal
amount to any unpurchased portion of the Notes surrendered; provided that each
such new Note shall be issued in an original principal amount in denominations
of $1,000 and integral multiples thereof. The Issuers shall send to the Trustee
and the holders of Notes on or as soon as practicable after the Change of
Control Payment Date a notice setting forth the results of the Change of Control
Offer.

          (d) The Issuers shall not be required to make a Change of Control
Offer if a third party makes the Change of Control Offer in the manner, at the
time and otherwise in compliance with the

                                       80
<PAGE>
 
requirements set forth herein applicable to a Change of Control Offer made by
the Issuers and purchases all Notes or portions thereof validly tendered and not
withdrawn under such Change of Control Offer.

          (e) The Issuers shall comply, to the extent applicable, with the
requirements of Section 14(e) of the Exchange Act and any other securities laws
or regulations in connection with the repurchase of Notes pursuant to this
covenant.

          SECTION 1013.  Limitation on Sales of Assets.
                         ----------------------------- 

          (a) Mediacom shall not, and shall not permit any Restricted Subsidiary
to, consummate an Asset Sale unless (i) Mediacom or such Restricted Subsidiary,
as the case may be, receives consideration at the time of such sale or other
disposition at least equal to the fair market value thereof (as determined in
good faith by the Executive Committee, whose determination shall be conclusive
and evidenced by a Committee Resolution); (ii) not less than 75% of the
consideration received by Mediacom or such Restricted Subsidiary, as the case
may be, is in the form of cash or Cash Equivalents; and (iii) the Asset Sale
Proceeds received by Mediacom or such Restricted Subsidiary are applied (a)
first, to the extent Mediacom elects, or is required, to prepay, repay or
purchase debt under any then existing Indebtedness of Mediacom or any Restricted
Subsidiary within 360 days following the receipt of the Asset Sale Proceeds from
any Asset Sale or, to the extent Mediacom elects, to make an investment in
assets (including Equity Interests or other securities purchased in connection
with the acquisition of Equity Interests or property of another Person) used or
useful in a Related Business, provided that such investment occurs and such
Asset Sale Proceeds are so applied within 360 days following the receipt of such
Asset Sale Proceeds (the "Reinvestment Date"), and (b) second, on a pro rata
basis (1) to the repayment of an amount of Other Pari Passu Debt not exceeding
the Other Pari Passu Debt Pro Rata Share (provided that any such repayment shall
result in a permanent reduction of any commitment in respect thereof in an
amount equal to the principal amount so repaid) and (2) if on the Reinvestment
Date with respect to any Asset Sale the Excess Proceeds exceed $10,000,000, the
Issuers shall apply an amount equal to such Excess Proceeds to an offer to
repurchase the Notes, at a purchase price in cash equal to 100% of the principal
amount thereof plus accrued and unpaid interest and Liquidated Damages, if any,
to the date of repurchase (an "Excess Proceeds Offer"); provided, that so long
as any of the 8 1/2% Notes are outstanding, the Issuers shall make such an
Excess Proceeds Offer, together with a similar pro rata offer to the holders of
the 8 1/2% Notes, and purchase any Notes and 8 1/2% Notes tendered in such
offers within 359 days following the receipt of the Asset Sales Proceeds.  If an
Excess Proceeds Offer is not fully subscribed, the Issuers may retain the
portion of the Excess Proceeds not required to repurchase Notes. For purposes of
determining in clause (ii) above the percentage of cash consideration received
by Mediacom or any Restricted Subsidiary, the amount of any (x) liabilities (as
shown on Mediacom's or such Restricted Subsidiary's most recent balance sheet)
of Mediacom or any Restricted Subsidiary that are actually assumed by the
transferee in such Asset Sale and from which Mediacom and the Restricted
Subsidiaries are fully released shall be deemed to be cash, and (y) securities,
notes or other similar obligations received by Mediacom or such Restricted
Subsidiary from such transferee that are immediately converted (or are converted
within 30 days of the related Asset Sale) by Mediacom or such Restricted
Subsidiary into cash shall be deemed to be cash in an amount equal to the net
cash proceeds realized upon such conversion.

          (b) If the Issuers are required to make an Excess Proceeds Offer, the
Issuers shall mail, within 30 days following the Reinvestment Date, a notice to
the holders of Notes stating, among other things: (1) that such holders have the
right to require the Issuers to apply the Excess Proceeds to repurchase such
Notes at a purchase price in cash equal to 100% of the principal amount thereof
plus accrued and unpaid interest and Liquidated Damages, if any, to the date of
purchase; (2) the purchase date, which shall be no earlier than 30 days and not
later than 60 days from the date such notice is mailed; (3) the instructions,
determined by the Issuers, that each holder must follow in order to have such
Notes

                                       81
<PAGE>
 
repurchased; and (4) the calculations used in determining the amount of Excess
Proceeds to be applied to the repurchase of such Notes. If the aggregate
principal amount of Notes surrendered by holders thereof exceeds the amount of
Excess Proceeds, the Trustee shall select the Notes to be purchased on a pro
rata basis or by lot or by such other method that the Trustee deems to be fair
and equitable to holders. Upon completion of the Excess Proceeds Offer, the
amount of Excess Proceeds shall be reset to zero.

          (c) The Issuers shall comply, to the extent applicable, with the
requirements of Section 14(e) of the Exchange Act and any other securities laws
or regulations in connection with the repurchase of Notes pursuant to this
covenant.

          (d) Notwithstanding the foregoing, Mediacom or any Restricted
Subsidiary shall be permitted to consummate an Asset Swap if (i) at the time of
entering into the related Asset Swap Agreement or immediately after giving
effect to such Asset Swap no Default or Event of Default shall have occurred and
be continuing or would occur as a consequence thereof and (ii) such Asset Swap
shall have been approved in good faith by the Executive Committee, whose
approval shall be conclusive and evidenced by a Committee Resolution, which
states that such Asset Swap is fair to Mediacom or such Restricted Subsidiary,
as the case may be, from a financial point of view.

          SECTION 1014.  Reports.
                         ------- 

          Whether or not the Issuers are subject to Section 13(a) or 15(d) of
the Exchange Act or any successor provision thereto, the Issuers shall file with
the SEC (if permitted by SEC practice and applicable law and regulations) so
long as the Notes are outstanding the annual reports, quarterly reports and
other periodic reports which the Issuers would have been required to file with
the SEC pursuant to Section 13(a) or 15(d) or any successor provision thereto if
the Issuers were so subject on or prior to the respective dates (the "Required
Filing Dates") by which the Issuers would have been required to file such
documents if the Issuers were so subject. The Issuers shall also in any event
(a) within 15 days of each Required Filing Date (whether or not permitted or
required to be filed with the SEC) (i) transmit or cause to be transmitted by
mail to all holders of Notes, at such holder's address appearing in the register
maintained by the Note Registrar, without cost to such holders, and (ii) file
with the Trustee, copies of the annual reports, quarterly reports and other
documents which the Issuers are required to file with the SEC pursuant to the
preceding sentence, or if such filing is not so permitted, information and data
of a similar nature, and (b) if, notwithstanding the preceding sentence, filing
such documents by the Issuers with the SEC is not permitted by SEC practice or
applicable law or regulations, promptly upon written request supply copies of
such documents to any holder of Notes. In addition, for so long as any Notes
remain outstanding and prior to the later of the consummation of the Exchange
Offer and the effectiveness of the Shelf Registration Statement, if required,
the Issuers shall furnish to holders and to securities analysts and prospective
investors, upon their request, the information required to be delivered pursuant
to Rule 144A(d)(4) under the Securities Act.

          SECTION 1015.  Limitation on Business Activities of Mediacom Capital.
                         ----------------------------------------------------- 

          Mediacom Capital shall not hold any material assets, become liable for
any material obligations, engage in any trade or business, or conduct any
business activity, other than the issuance of Equity Interests to Mediacom or
any Wholly Owned Restricted Subsidiary, the Incurrence of Indebtedness as a co-
obligor or guarantor of Indebtedness Incurred by Mediacom, including the Notes,
that is permitted to be Incurred by Mediacom under Section 1008 (provided that
the net proceeds of such Indebtedness are retained by Mediacom or loaned to or
contributed as capital to one or more of the Restricted Subsidiaries other than
Mediacom Capital), and activities incidental thereto. Neither Mediacom nor any
Restricted Subsidiary shall engage in any transactions with Mediacom Capital in
violation of the immediately preceding sentence.

                                       82
<PAGE>
 
          SECTION 1016.  Statement by Officers as to Default.
                         ----------------------------------- 

          (a) The Issuers will deliver to the Trustee, within 120 days after the
end of each fiscal year, an Officers' Certificate meeting the requirements of
Section 103 stating that a review of the activities of the Issuers and its
Restricted Subsidiaries during the preceding fiscal year has been made under the
supervision of the signing officers with a view to determining whether it has
kept, observed, performed and fulfilled, and has caused each of its Restricted
Subsidiaries to keep, observe, perform and fulfill its obligations under this
Indenture and further stating, as to each such officer signing such certificate,
that, to the best of his or her knowledge, the Issuers during such preceding
fiscal year has kept, observed, performed and fulfilled, and has caused each of
its Restricted Subsidiaries to keep, observe, perform and fulfill each and every
such covenant contained in this Indenture and no Event of Default occurred
during such year and at the date of such certificate there is no Event of
Default which has occurred and is continuing or, if such signers do know of such
Event of Default, the certificate shall describe its status with particularity
and shall state what action the Issuers are taking or propose to take in respect
thereof and that, to the best of his or her knowledge, no event has occurred and
remains by reason of which payments on the account of the principal of or
interest, if any, on the Notes is prohibited or if such event has occurred, a
description of the event and what action each is taking or proposes to take with
respect thereto.  The Officers' Certificate shall also notify the Trustee should
the Issuers elect to change the manner in which it fixes it fiscal year end.
For purposes of this Section 1016(a), such compliance shall be determined
without regard to any period of grace or requirement of notice under this
Indenture.

          (b) When any Default has occurred and is continuing under this
Indenture, or if the trustee for or the holder of any other evidence of
Indebtedness of the Issuers or any Significant Subsidiary gives any notice or
takes any other action with respect to a claimed Default (other than with
respect to Indebtedness in the principal amount of less than $15,000,000), the
Issuers shall deliver to the Trustee by registered or certified mail or
facsimile transmission an Officers' Certificate specifying such event, notice or
other action within five Business Days of its occurrence.

          SECTION 1017.  Limitation on Guarantees of Certain Indebtedness.
                         ------------------------------------------------ 

          (a) Mediacom shall not (i) permit any Restricted Subsidiary to
guarantee any Indebtedness of either Issuer other than the Notes (the "Other
Indebtedness"), or (ii) pledge any intercompany Indebtedness representing
obligations of any of its Restricted Subsidiaries to secure the payment of Other
Indebtedness, in each case unless such Restricted Subsidiary, the Issuers and
the Trustee execute and deliver a supplemental indenture pursuant to Section 901
causing such Restricted Subsidiary to guarantee (the "Restricted Subsidiary
Guarantee") the Issuers' obligations under this Indenture and the Notes to the
same extent that such Restricted Subsidiary guaranteed the Issuers' obligations
under the Other Indebtedness (including waiver of subrogation, if any).
Thereafter, such Restricted Subsidiary shall be a Guarantor for all purposes of
this Indenture.

          (b) The guarantee of a Restricted Subsidiary shall be released upon
(i) the sale of all of the Equity Interests, or all or substantially all of the
assets, of the applicable Guarantor (in each case other than to Mediacom or a
Subsidiary), (ii) the designation by Mediacom of the applicable Guarantor as an
Unrestricted Subsidiary pursuant to Section 1018, or (iii) the release of the
guarantee of such Guarantor with respect to the obligations which caused such
Guarantor to deliver the Restricted Subsidiary Guarantee in accordance with the
preceding paragraph, in each case in compliance with this Indenture (including,
in the event of a sale of Equity Interests or assets described in clause (i)
above, that the net cash proceeds are applied in accordance with the
requirements of Section 1013).

          (c) The Trustee shall, at the sole cost and expense of the Issuers,
upon receipt of a request by the Issuers accompanied by an Officers' Certificate
certifying as to the compliance with

                                       83
<PAGE>
 
paragraph (b) of this Section and, with respect to clause (i) or (ii) of
paragraph (b) of this Section, upon receipt at the reasonable request of the
Trustee of an Opinion of Counsel that the provisions of this Section have been
complied with, deliver an appropriate instrument evidencing such release. Any
Guarantor not so released remains liable for the full amount of principal of and
interest on the Notes and the other obligations of the Issuers provided herein.

          SECTION 1018.  Designation of Unrestricted Subsidiaries.
                         ---------------------------------------- 

          (a) Mediacom may designate any Subsidiary (including any newly
acquired or newly formed Subsidiary or a Person becoming a Subsidiary through
merger or consolidation or Investment therein) as an "Unrestricted Subsidiary"
under this Indenture (a "Designation") only if (a) no Default or Event of
Default shall have occurred and be continuing at the time of or after giving
effect to such Designation; (b) at the time of and after giving effect to such
Designation, Mediacom would be able to Incur $1.00 of additional Indebtedness
under the Debt to Operating Cash Flow Ratio under the first paragraph of Section
1008; and (c) Mediacom would be permitted to make a Restricted Payment at the
time of Designation (assuming the effectiveness of such Designation) pursuant to
paragraph (a) of Section 1007 in an amount (the "Designation Amount") equal to
Mediacom's proportionate interest in the fair market value of such Subsidiary on
such date (as determined in good faith by the Executive Committee, whose
determination shall be conclusive and evidenced by a Committee Resolution).
Notwithstanding the foregoing, neither Mediacom Capital nor any of its
Subsidiaries may be designated as Unrestricted Subsidiaries.

          (b) At the time of Designation all of the Indebtedness of such
Unrestricted Subsidiary shall consist of, and shall at all times thereafter
consist of, Non-Recourse Indebtedness, and neither Mediacom nor any Restricted
Subsidiary shall at any time have any direct or indirect obligation to (x) make
additional Investments (other than Permitted Investments) in any Unrestricted
Subsidiary or (y) maintain or preserve the financial condition of any
Unrestricted Subsidiary or cause any Unrestricted Subsidiary to achieve any
specified levels of operating results or (z) be party to any agreement,
contract, arrangement or understanding with any Unrestricted Subsidiary unless
the terms of any such agreement, contract, arrangement or understanding are no
less favorable to Mediacom or such Restricted Subsidiary than those that might
be obtained, in light of all the circumstances, at the time from Persons who are
not Affiliates of Mediacom. If, at any time, any Unrestricted Subsidiary would
violate the foregoing requirements, it shall thereafter cease to be an
Unrestricted Subsidiary for purposes of this Indenture and any Indebtedness of
such Subsidiary shall be deemed to be Incurred as of such date.

          (c) Mediacom may revoke any Designation of a Subsidiary as an
Unrestricted Subsidiary (a "Revocation") if (a) no Default or Event of Default
shall have occurred and be continuing at the time of or after giving effect to
such Revocation; (b) at the time of and after giving effect to such Revocation,
Mediacom would be able to Incur $1.00 of additional Indebtedness under the Debt
to Operating Cash Flow Ratio of the first paragraph of Section 1008; and (c) all
Liens and Indebtedness of such Unrestricted Subsidiary outstanding immediately
following such Revocation would, if Incurred at such time, have been permitted
to be Incurred for all purposes of this Indenture.

          (d) All Designations and Revocations must be evidenced by Committee
Resolutions delivered to the Trustee certifying compliance with the foregoing
provisions.

                                       84
<PAGE>
 
                                ARTICLE ELEVEN.
                              REDEMPTION OF NOTES

          SECTION 1101.  Optional Redemption.
                         ------------------- 

          The Notes may or shall, as the case may be, be redeemed, as a whole or
from time to time in part, subject to the conditions and at the redemption
prices specified in the Form of Note (Section 203), together with accrued and
unpaid interest and Liquidated Damages, if any, thereon to the date of
redemption.

          SECTION 1102.  Applicability of Article.
                         ------------------------ 

          Redemption of Notes at the election of the Issuers or otherwise, as
permitted or required by any provision of this Indenture, shall be made in
accordance with such provision and this Article.

          SECTION 1103.  Election to Redeem; Notice to Trustee.
                         ------------------------------------- 

          The election of the Issuers to redeem any Notes pursuant to Section
1101 shall be evidenced by a Committee Resolution. In case of any redemption at
the election of the Issuers, the Issuers shall, at least 90 days prior to the
date of redemption (the "Redemption Date") fixed by the Issuers (unless a
shorter notice shall be satisfactory to the Trustee), notify the Trustee of such
Redemption Date and of the principal amount of Notes to be redeemed and shall
deliver to the Trustee such documentation and records as shall enable the
Trustee to select the Notes to be redeemed pursuant to Section 1104.

          SECTION 1104.  Selection by Trustee of Notes to Be Redeemed.
                         -------------------------------------------- 

          If fewer than all the Notes are to be redeemed, the Trustee will
select the Notes to be redeemed, if the Notes are listed on a national
securities exchange, in accordance with the rules of such exchange or, if the
Notes are not so listed, on a pro rata basis or by lot or by such other method
that the Trustee deems to be fair and equitable to holders. If any Note is to be
redeemed in part only, the notice of redemption that relates to such Note shall
state the portion of the principal amount thereof to be redeemed and a new Note
or Notes in principal amount equal to the unredeemed principal portion thereof
will be issued; provided, that no Notes of a principal amount of $1,000 or less
shall be redeemed in part. On and after the Redemption Date, interest will cease
to accrue on Notes or portions thereof called for redemption as long as the
Issuers have deposited with the Paying Agent for the Notes funds in satisfaction
of the applicable redemption price pursuant to this Indenture.

          The Trustee shall promptly notify the Issuers in writing of the Notes
selected for redemption and, in the case of any Notes selected for partial
redemption, the principal amount thereof  to be redeemed.

          For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to redemption of Notes shall relate, in the
case of any Note redeemed or to be redeemed only in part, to the portion of the
principal amount of such Note which has been or is to be redeemed.

          SECTION 1105.  Notice of Redemption.
                         -------------------- 

          Notice of redemption shall be given in the manner provided for in
Section 106 not less than 30 nor more than 60 days' prior to the Redemption Date
by first class mail to each Holder of Notes to be redeemed at such Holder's
address appearing in the Note Register.  The Trustee shall give notice of
redemption in the Issuers' name and at the Issuers' expense; provided, however,
that the Issuers shall

                                       85
<PAGE>
 
deliver to the Trustee, at least 45 days prior to the Redemption Date, an
Officers' Certificate requesting that the Trustee give such notice and setting
forth the information to be stated in such notice as provided in the following
items.

          All notices of redemption shall state:

          (i)    the Redemption Date,

          (ii)   the Redemption Price and the amount of accrued interest to the
     Redemption Date payable as provided in Section 1107, if any,

          (iii)  if less than all outstanding Notes are to be redeemed, the
     identification of the particular Notes (or portion thereof) to be redeemed,
     as well as the aggregate principal amount of Notes to be redeemed and the
     aggregate principal amount of Notes to be outstanding after such partial
     redemption,

          (iv)   in case any Note is to be redeemed in part only, the notice
     which relates to such Note shall state that on and after the Redemption
     Date, upon surrender of such Note, the holder will receive, without charge,
     a new Note or Notes of authorized denominations for the principal amount
     thereof remaining unredeemed,

          (v)    that on the Redemption Date the Redemption Price (and accrued
     interest, if any, to the Redemption Date payable as provided in Section
     1107) will become due and payable upon each such Note, or the portion
     thereof, to be redeemed, and, unless the Issuers defaults in making the
     redemption payment, that interest on Notes called for redemption (or the
     portion thereof) will cease to accrue on and after said date,

          (vi)   the place or places where such Notes are to be surrendered for
     payment of the Redemption Price and accrued interest, if any,

          (vii)  the name and address of the Paying Agent,

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

          (ix)   the CUSIP number, and that no representation is made as to the
     accuracy or correctness of the CUSIP number, if any, listed in such notice
     or printed on the Notes, and

          (x)    the paragraph of the Notes or Section of this Indenture
     pursuant to which the Notes are to be redeemed.

          SECTION 1106.  Deposit of Redemption Price.
                         --------------------------- 

          Prior to any Redemption Date, the Issuers shall deposit with the
Trustee or with a Paying Agent (or, if the Issuers are acting as their own
Paying Agent, segregate and hold in trust as provided in Section 1003) an amount
of money sufficient to pay the Redemption Price of, and accrued interest on, all
the Notes which are to be redeemed on that date.

                                       86
<PAGE>
 
          SECTION 1107.  Notes Payable on Redemption Date.
                         -------------------------------- 

          Notice of redemption having been given as aforesaid, the Notes so to
be redeemed shall, on the Redemption Date, become due and payable at the
Redemption Price therein specified (together with accrued interest, if any, to
the Redemption Date), and from and after such date (unless the Issuers shall
default in the payment of the Redemption Price and accrued interest) such Notes
shall cease to bear interest. Upon surrender of any such Note for redemption in
accordance with said notice, such Note shall be paid by the Issuers at the
Redemption Price, together with accrued interest, if any, to the Redemption
Date; provided, however, that installments of interest whose Stated Maturity is
on or prior to the Redemption Date shall be payable to the Holders of such
Notes, or one or more predecessor Notes, registered as such at the close of
business on the relevant Regular Record Date or Special Record Date, as the case
may be, according to their terms and the provisions of Section 311.

          If any Note called for redemption shall not be so paid upon surrender
thereof for redemption, the principal (and premium, if any) shall, until paid,
bear interest from the Redemption Date at the rate borne by the Notes.

          SECTION 1108.  Notes Redeemed in Part.
                         ---------------------- 

          Any Note which is to be redeemed only in part (pursuant to the
provisions of this Article) shall be surrendered at the office or agency of the
Issuers maintained for such purpose pursuant to Section 1002 (with, if the
Issuers or the Trustee so requires, due endorsement by, or a written instrument
of transfer in form satisfactory to the Issuers and the Trustee duly executed
by, the Holder thereof or such Holder's attorney duly authorized in writing),
and the Issuers shall execute, and the Trustee shall authenticate and deliver to
the Holder of such Note at the expense of the Issuers, a new Note or Notes, of
any authorized denomination as requested by such Holder, in an aggregate
principal amount equal to and in exchange for the unredeemed portion of the
principal of the Note so surrendered, provided, that each such new Note will be
in a principal amount of $1,000 or integral multiple thereof.

                                ARTICLE TWELVE.
                       DEFEASANCE AND COVENANT DEFEASANCE

          SECTION 1201.  The Issuers' Option to Effect Defeasance or Covenant
                         ----------------------------------------------------
Defeasance.
---------- 

          The Issuers may, at their option, at any time, with respect to the
Notes, elect to have either Section 1202 or Section 1203 be applied to all
outstanding Notes upon compliance with the conditions set forth in this Article
Twelve. The Issuers in their sole discretion can defease the Notes.

          SECTION 1202.  Defeasance and Discharge.
                         ------------------------ 

          Upon the Issuers' exercise under Section 1201 of the option applicable
to this Section 1202, the Issuers shall be deemed to have been discharged from
any and all obligations with respect to all outstanding Notes on the date the
conditions set forth in Section 1204 are satisfied (hereinafter, "Defeasance").
For this purpose, such Defeasance means that the Issuers shall be deemed to have
paid and discharged the entire Indebtedness represented by the outstanding
Notes, which shall thereafter be deemed to be "outstanding" only for the
purposes of Section 1205 and the other Sections of this Indenture referred to in
(i) and (ii) below, 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 Issuers, shall execute proper instruments acknowledging
the same), except for the following which shall survive until

                                       87
<PAGE>
 
otherwise terminated or discharged hereunder: (i) the rights of Holders of
outstanding Notes to receive, solely from the trust fund described in Section
1204 and as more fully set forth in such Section, payments in respect of the
principal of (and premium, if any, on) and interest on such Notes when such
payments are due, (ii) the Issuers' obligations with respect to such Notes under
Sections 304, 305, 310, 1002 and 1003, (iii) the rights, powers, trusts, duties
and immunities of the Trustee hereunder, and the Issuers' obligations in
connection therewith and (iv) this Article Twelve.

          If the Issuers exercise their Defeasance option, payment of the Notes
may not be accelerated because of an Event of Default.

          Subject to compliance with this Article Twelve, the Issuers may
exercise their option under this Section 1202 notwithstanding the prior exercise
of their option under Section 1203 with respect to the Notes.

          SECTION 1203.  Covenant Defeasance.
                         ------------------- 

          Upon the Issuers' exercise under Section 1201 of the option applicable
to this Section 1203, the Issuers may terminate (i) its obligations under any
covenant contained in Sections 1007 through 1015 and Section 1017, (ii) the
operation of Section 501(iv), Section 501(v), Section 501(vi) (with respect only
to Significant Subsidiaries), Section 501(vii) (with respect only to Significant
Subsidiaries) and Section 501(iii) and (iii) the limitations contained in
Sections 801(iii) and 801(iv) (hereinafter, "Covenant Defeasance"), and the
Notes shall thereafter be deemed not to be "outstanding" for the purposes of any
direction, waiver, consent or declaration or Act of Holders (and the
consequences of any thereof) in connection with such covenants, but shall
continue to be deemed "outstanding" for all other purposes hereunder (it being
understood that such Notes will not be outstanding for accounting purposes).  If
the Issuers exercise their covenant defeasance option, payment of the Notes may
not be accelerated because of an Event of Default specified under Section
501(iv), (v), (vi) (with respect only to Significant Subsidiaries), (vii) (with
respect only to Significant Subsidiaries) and Section 501(viii) or because of
the failure of the Issuers to comply with Section 801(iii) and 801(iv).  For
this purpose, such Covenant Defeasance means that, with respect to the
outstanding Notes, the Issuers may omit to comply with and shall have no
liability in respect of any term, condition or limitation set forth in any such
covenant, whether directly or indirectly, by reason of any reference elsewhere
herein to any such covenant or by reason of any reference in any such covenant
to any other provision herein or in any other document and such omission to
comply shall not constitute a Default or an Event of Default under Section
501(iii), but, except as specified above, the remainder of this Indenture and
such Notes shall be unaffected thereby.

          SECTION 1204.  Conditions to Defeasance or Covenant Defeasance.
                         ----------------------------------------------- 

          The following shall be the conditions to application of either Section
1202 or Section 1203 to the outstanding Notes:

          (i)   the Issuers shall irrevocably have deposited or caused to be
     deposited with the Trustee (or another trustee satisfying the requirements
     of this Indenture who shall agree to comply with the provisions of this
     Article Twelve applicable to it) as trust funds in trust money or U.S.
     Government Obligations, in such amounts as will be sufficient, in the
     opinion of a nationally recognized firm of independent public accountants
     selected by the Issuers, to pay the principal of, premium, if any, and
     Liquidated Damages, if any, and interest due on the outstanding Notes on
     the Stated Maturity or on the applicable Redemption Date as the case may
     be, of such principal, premium, if any, or interest on the outstanding
     Notes;

                                       88
<PAGE>
 
          (ii)   in the case of Defeasance, the Issuers shall have delivered to
     the Trustee an Opinion of Counsel in the United States reasonably
     acceptable to the Trustee (which opinion may be subject to customary
     assumptions and exclusions) confirming that (A) the Issuers have received
     from, or there has been published by, the United States Internal Revenue
     Service a ruling or (B) since the Issue Date, there has been a change in
     the applicable U.S. federal income tax law, in either case to the effect
     that, and based thereon such Opinion of Counsel in the United States (which
     opinion may be subject to customary assumptions and exclusions) shall
     confirm that the Holders of the outstanding Notes will not recognize
     income, gain or loss for U.S. federal income tax purposes as a result of
     such Defeasance and will be subject to U.S. federal income tax on the same
     amounts, in the same manner and at the same times as would have been the
     case if such Defeasance had not occurred;

          (iii)  Mediacom shall have delivered to the Trustee an Opinion of
     Counsel in the United States reasonably acceptable to the Trustee
     confirming that, subject to customary assumptions and exclusions, the
     Holders of the outstanding Notes will not recognize income, gain or loss
     for U.S. federal income tax purposes as a result of such Defeasance or
     Covenant Defeasance and will be subject to such tax on the same amounts, in
     the same manner and at the same times as would have been the case if such
     Defeasance or Covenant Defeasance had not occurred;

          (iv)   no Default or Event of Default shall have occurred and be
     continuing on the date of such deposit or insofar as Events of Default from
     bankruptcy or insolvency events are concerned, at any time in the period
     ending on the 91st day after the date of deposit;

          (v)    such Defeasance or Covenant Defeasance shall not result in a
     breach or violation of, or constitute a default under, any material
     agreement or instrument (other than this Indenture) to which the Issuers is
     a party or by which the Issuers is bound;

          (vi)   Mediacom shall have delivered to the Trustee an Opinion of
     Counsel to the effect that, (A) as of the date of such opinion and subject
     to customary assumptions and exclusions following the deposit, the trust
     funds will not be subject to the effect of any applicable bankruptcy,
     insolvency, reorganization or similar laws affecting creditors' rights
     generally under any applicable U.S. federal or state law, and that the
     Trustee has a perfected security interest in such trust funds for the
     ratable benefit of the Holders and (B) such Defeasance or Covenant
     Defeasance, as the case may be, will not require registration of the
     Issuers, the Trustee or the trust fund under the Investment Company Act of
     1940, as amended or the Investment Advisors Act of 1940, as amended;

          (vii)  The Issuers shall have delivered to the Trustee an Officers'
     Certificate stating that the deposit was not made by the Issuers with the
     intent of defeating, hindering, delaying or defrauding any creditors of the
     Issuers or others;

          (viii) The Issuers shall have delivered to the Trustee an Officers'
     Certificate and an Opinion of Counsel in the United States (which Opinion
     of Counsel may be subject to customary assumptions and exclusions) each
     stating that all conditions precedent provided for or relating to the
     Defeasance or the Covenant Defeasance, as the case may be, have been
     complied with; and

          (ix)   The Issuers shall have delivered to the Trustee the opinion of
     a nationally recognized firm of independent public accountants stating the
     matters set forth in paragraph (i) above.

                                       89
<PAGE>
 
          SECTION 1205.  Deposited Money and U.S. Government Obligations to Be
                         -----------------------------------------------------
                         Held in Trust; Other Miscellaneous Provisions.
                         --------------------------------------------- 

          Subject to the provisions of the last paragraph of Section 1003, all
money and U.S. Government Obligations  (including the proceeds thereof)
deposited with the Trustee (or other qualifying trustee, collectively for
purposes of this Section 1205, the "Trustee") pursuant to Section 1204 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 (including the Issuers
acting as their own 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 premium, if any) and interest, but such money need not be segregated from
other funds except to the extent required by law.

          The Issuers shall pay and indemnify the Trustee against any tax, fee
or other charge imposed on or assessed against the Government Obligations
deposited pursuant to Section 1204 or the principal and interest received in
respect thereof.

          Anything in this Article Twelve to the contrary notwithstanding, the
Trustee shall deliver or pay to the Issuers from time to time upon the Issuers'
Request any money or U.S. Government Obligations held by it as provided in
Section 1204 which, in the opinion of a nationally recognized firm of
independent public accountants expressed in a written certification thereof
delivered to the Trustee, are in excess of the amount thereof which would then
be required to be deposited to effect an equivalent defeasance or covenant
defeasance, as applicable, in accordance with this Article.

          SECTION 1206.  Reinstatement.
                         ------------- 

          If the Trustee or any Paying Agent is unable to apply any money or
U.S. Government Obligations in accordance with Section 1205 by reason of any
legal proceeding or by any reason of any order or judgment of any court or
governmental authority enjoining, restraining or otherwise prohibiting such
application, then the Issuers' obligations under this Indenture and the Notes
shall be revived and reinstated as though no deposit had occurred pursuant to
Section 1202 or 1203, as the case may be, until such time as the Trustee or
Paying Agent is permitted to apply all such money in accordance with Section
1205; provided, however, that if the Issuers makes any payment of principal of
(or premium, if any) or interest on any Note following the reinstatement of its
obligations, the Issuers shall be subrogated to the rights of the Holders of
such Notes to receive such payment from the money and U.S. Government
Obligations held by the Trustee or Paying Agent.

                               ARTICLE THIRTEEN.
                        RESTRICTED SUBSIDIARY GUARANTEE

          SECTION 1301.  Unconditional Guarantee.
                         ----------------------- 

          Each Guarantor hereby unconditionally, jointly and severally,
guarantees to each Holder of a Note authenticated and delivered by the Trustee
and to the Trustee and its successors and assigns that:  the principal of and
interest and Liquidated Damages, if any, on the Notes shall be promptly paid in
full when due, subject to any applicable grace period, whether at maturity, by
acceleration or otherwise, and interest and Liquidated Damages, if any, on the
overdue principal and interest on any overdue interest on the Notes and all
other obligations of the Issuers to the Holders or the Trustee hereunder or
under the Notes shall be promptly paid in full or performed, all in accordance
with the terms hereof and thereof; subject, however, to the limitations set
forth in Section 1303.  Each Guarantor hereby agrees that its obligations
hereunder shall be unconditional, irrespective of the validity, regularity or
enforceability of the Notes or this Indenture, the absence of the any action to
enforce the same, any waiver or consent by

                                       90
<PAGE>
 
any Holder of the Notes with respect to any provisions hereof or thereof, the
recovery of any judgment against the Issuers, any action to enforce the same or
any other circumstance which might otherwise constitute a legal or equitable
discharge or defense of a guarantor. Each Guarantor hereby waives diligence,
presentment, demand of payment, filing of claims with a court in the event of
insolvency or bankruptcy of the Issuers, any right to require a proceeding first
against the Issuers, protest, notice and all demands whatsoever and covenants
that the Restricted Subsidiary Guarantee will not be discharged except by
complete performance of the obligations contained in the Notes, this Indenture,
and this Restricted Subsidiary Guarantee. If any Holder or the Trustee is
required by any court or otherwise to return to the Issuers, any Guarantor, or
any custodian, trustee, liquidator or other similar official acting in relation
to the Issuers or any Guarantor, any amount paid by the Issuers to any Guarantor
to the Trustee or such Holder, this Restricted Subsidiary Guarantee, to the
extent theretofore discharged, shall be reinstated in full force and effect.
Each Guarantor further agrees that, as between each Guarantor, on the one hand,
and the Holders and the Trustee, on the other hand, (x) the maturity of the
obligations guaranteed hereby may be accelerated as provided in Article Five for
the purpose of this Restricted Subsidiary Guarantee, notwithstanding any stay,
injunction or other prohibition preventing such acceleration in respect of the
obligations guaranteed hereby, and (y) in the event of any acceleration in
respect of such obligations as provided in Article Five, such obligations
(whether or not due and payable) shall forthwith become due and payable by each
Guarantor for the purpose of this Restricted Subsidiary Guarantee.

          SECTION 1302.  Severability.
                         ------------ 

          In case any provision of this Restricted Subsidiary Guarantee 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 1303.  Limitation of Guarantor's Liability.
                         ----------------------------------- 

          Each Guarantor, and by its acceptance hereof each Holder and the
Trustee, hereby confirms that it is the intention of all such parties that the
guarantee by such Guarantor pursuant to its Restricted Subsidiary Guarantee not
constitute a fraudulent transfer or conveyance for purposes of title 11 of the
United States Code, as amended, the Uniform Fraudulent Conveyance Act, the
Uniform Fraudulent Transfer Act or any similar U.S. Federal or state or other
applicable law or that the obligations of such Guarantor under Section 1301
would otherwise be held or determined to be void, invalid or unenforceable on
account of the amount of its liability under said Section 1301.  To effectuate
the foregoing intention, the Holders and such Guarantor hereby irrevocably agree
that the obligations of such Guarantor under the Restricted Subsidiary Guarantee
shall be limited to the maximum amount as will, after giving effect to all other
contingent and fixed liabilities of such Guarantor and after giving effect to
any collections from or payments made by or on behalf of any other Guarantor in
respect of the obligations of such other Guarantor under its Restricted
Subsidiary Guarantee or pursuant to Section 1304, result in the obligations of
such Guarantor under the Restricted Subsidiary Guarantee not constituting such
fraudulent transfer or conveyance and not being held or determined to be void,
invalid or unenforceable.

          SECTION 1304.  Contribution.
                         ------------ 

          In order to provide for just and equitable contribution among the
Guarantors, the Guarantors agree, inter se, that in the event any payment or
distribution is made by any Guarantor (a "Funding Guarantor") under the
Restricted Subsidiary Guarantee, such Funding Guarantor shall be entitled to a
contribution from all other Guarantors in a pro rata amount, based on the net
assets of each Guarantor (including the Funding Guarantor), determined in
accordance with GAAP, subject to Section 1303, for all payments, damages and
expenses incurred by that Funding Guarantor in discharging the

                                       91
<PAGE>
 
Issuers' obligations with respect to the Notes or any other Guarantor's
obligations with respect to the Restricted Subsidiary Guarantee.

          SECTION 1305.  Additional Guarantors.
                         --------------------- 

          Any Restricted Subsidiary which is required pursuant to Section 1017
to become a Guarantor shall (a) execute and deliver to the Trustee a
supplemental indenture in form and substance reasonably satisfactory to the
Trustee which subjects such Restricted Subsidiary to the provisions of this
Indenture as a Guarantor and pursuant to which such Restricted Subsidiary agrees
to guarantee to each Holder of a Note the payment of allowances due in respect
of the Notes in accordance with the provisions of this Indenture, and (b) cause
to be delivered to the Trustee an Opinion of Counsel to the effect that such
supplemental indenture has been duly authorized and executed by such Restricted
Subsidiary and constitutes the legal, valid, binding and enforceable obligation
of such Restricted Subsidiary (subject to such customary exceptions concerning
fraudulent conveyance laws, creditors' rights and equitable principles).

          SECTION 1306.  Subordination of Subrogation and Other Rights.
                         --------------------------------------------- 

          Each Guarantor hereby agrees that any claim against the Issuers that
arises from the payment, performance or enforcement of such Guarantor's
obligations under its Restricted Subsidiary Guarantee or this Indenture,
including, without limitation, any right of subrogation, shall be subject and
subordinate to, and no payment with respect to any such claim of such Guarantor
shall be made before, the payment in full in cash of all outstanding Notes in
accordance with the provisions provided therefor in this Indenture.

                                       92
<PAGE>
 
          IN WITNESS WHEREOF, the parties hereto have caused this Indenture to
be duly executed as of the day and year first above written.

                              MEDIACOM LLC



                              By /s/ MARK E. STEPHAN
                                ---------------------------------- 
                                 Name: Mark E. Stephan
                                 Title: Chief Financial Officer

                              MEDIACOM CAPITAL CORPORATION



                              By /s/ MARK E. STEPHAN
                                ---------------------------------- 
                                 Name: Mark E. Stephan
                                 Title: Chief Financial Officer


                              BANK OF MONTREAL TRUST COMPANY



                              By /s/ PETER MORSE
                                ---------------------------------- 
                                 Name: Peter Morse
                                 Title: Vice President

                                       93