Document:

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                                                                     EXHIBIT 4.7

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AS
AMENDED, OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE SOLD, OFFERED FOR SALE,
PLEDGED, OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
RELATED THERETO OR AN OPINION OF COUNSEL (WHICH MAY BE COMPANY COUNSEL)
REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE SECURITIES
LAWS.

                               WARRANT AGREEMENT

             To Purchase Shares of the Series D Preferred Stock of

                           CHORUM TECHNOLOGIES INC.

               Dated as of March 1, 2000 (the "Effective Date")

WHEREAS, CHORUM TECHNOLOGIES INC., a Delaware corporation (the "Company") has
entered into Equipment Schedule No. VL-5 and VL-6 dated as of March 1, 2000 to
Master Lease Agreement dated as of September 22, 1998, and related Summary
Equipment Schedules (collectively, the "Leases") with Comdisco, Inc., a Delaware
corporation (the 'Warrantholder"); and

WHEREAS, the Company desires to grant to Warrantholder in consideration for such
Leases, the right to purchase shares of its Series D Preferred Stock;

NOW, THEREFORE, in consideration of the Warrantholder executing and delivering
such Leases and in consideration of mutual covenants and agreements contained
herein, the Company and Warrantholder agree as follows:

1.   GRANT OF THE RIGHT TO PURCHASE PREFERRED STOCK.

The Company hereby grants to the Warrantholder, and the Warrantholder is
entitled, upon the terms and subject to the conditions hereinafter set forth, to
subscribe to and purchase from the Company 77,088 fully paid and non-assessable
shares of the Company's Series D Preferred Stock ("Preferred Stock") at a
purchase price of $4.67 per share (the "Exercise Price"). The number and
purchase price of such shares are subject to adjustment as provided in Section 8
hereof.
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2.   TERM OF THE WARRANT AGREEMENT.

Except as otherwise provided for herein, the term of this Warrant Agreement and
the right to purchase Preferred Stock as granted herein shall commence on the
Effective Date and shall be exercisable for a period of (i) seven (7) years or
(ii) three (3) years from the effective date of the Company's initial public
offering, whichever is shorter. Notwithstanding the term of this Warrant
Agreement fixed pursuant to preceding sentence, the right to purchase Preferred
Stock a granted herein shall expire, if not previously exercised, immediately
upon (i) a merger or consolidation of the Company with or into any other
corporation or corporations, unless the shareholders of the Company immediately
prior to any such transaction are holders of a majority of the voting securities
of the surviving corporation or acquiring corporation immediately thereafter and
hold such securities in substantially similar proportions as prior to such
transaction (and for purposes of this calculation equity securities which any
shareholder of the Company owned immediately prior to such merger or
consolidation as shareholder of another party to the transaction shall be
disregarded), or (ii) a sale or other transfer of all or substantially all of
the assets of the Company or any series of related transactions resulting in the
sale or other transfer of all or substantially all of the assets of the Company
("Termination Event").

The Company shall notify the Warrantholder if the Termination Event is proposed
no later than the date such notice is provided to the Company's stockholders of
such Termination Event. Such notice shall also contain such details of the
proposed Termination Event as are reasonable in the circumstances. If such
closing does not take place, the Company shall promptly notify the Warrantholder
that such proposed transaction has been terminated, and the Warrantholder may
rescind any exercise of its purchase rights promptly after such notice of
termination of the proposed transaction. In the event of such recission, this
Warrant Agreement shall continue to be exercisable on the same terms and
conditions contained herein.

If all of the Company's outstanding Preferred Stock is converted into shares of
Common Stock then this Warrant shall automatically become exercisable for that
number of shares of Common Stock equal to the number of shares of Common Stock
that would have been received if this Warrant had been exercised in full and the
shares of Preferred Stock received thereupon had been simultaneously converted
into shares of Common Stock immediately prior to such event, and the Exercise
Price shall be automatically adjusted to equal the amount obtained by dividing
(i) the aggregate Exercise Price of the shares of Preferred Stock for which this
Warrant was exercisable immediately prior to such conversion, by (ii) the number
of shares of Common Stock for which this Warrant is exercisable immediately
after such conversion.

3.   EXERCISE OF THE PURCHASE RIGHTS.

The purchase rights set forth in this Warrant Agreement are exercisable by the
Warrantholder, in whole or in part, at any time, or from time to time, prior to
the expiration of the term set forth in Section 2 above, by tendering to the
Company at its principal office a notice of exercise in the form attached hereto
as Exhibit I (the "Notice of Exercise"), duly completed and executed. Promptly
upon receipt of the Notice of Exercise and the payment of the purchase price in
accordance with the terms set forth below, and in no event later than twenty-one
(21) days thereafter, the Company shall issue to the Warrantholder a certificate
for the number of shares of

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Preferred Stock purchased and shall execute the acknowledgment of exercise in
the form attached hereto as Exhibit II (the "Acknowledgment of Exercise")
indicating the number of shares which remain subject to future purchases, if
any.

The Exercise Price may be paid at the Warrantholder's election either (i) by
cash or check, or (ii) by surrender of Warrants ("Net Issuance") as determined
below. If the Warrantholder elects the Net Issuance method, the Company will
issue Preferred Stock in accordance with the following formula:

X  =  Y(A-B)
      ------
         A

Where: X =   the number of shares of Preferred Stock to be issued to the
Warrantholder.

Y = the number of shares of Preferred Stock requested to be exercised under this
Warrant Agreement.

A = the fair market value of one (1) share of Preferred Stock at the time the
net issuance election is made.

B = the Exercise Price.

For purposes of the above calculation, current fair market value of Preferred
Stock shall mean with respect to each share of Preferred Stock:

(i)   if the exercise is in connection with an initial public offering of the
Company's Common Stock, and if the Company's Registration Statement relating to
such public offering has been declared effective by the SEC, then the fair
market value per share shall be the product of (x) the initial "Price to Public"
specified in the final prospectus with respect to the offering and (y) the
number of shares of Common Stock into which each share of Preferred Stock is
convertible at the time of such exercise;

(ii)  if this Warrant is exercised after, and not in connection with the
Company's initial public offering, and:

(a)   if traded on a securities exchange, the fair market value shall be deemed
to be the average of the closing prices over a twenty-one (21) day period ending
three days before the day the current fair market value of the securities is
being determined ; or

(b)   if actively traded over-the-counter, the fair market value shall be deemed
to be the average of the closing bid and asked prices quoted on the NASDAQ
system (or similar system) over the twenty-one (21) day period ending three days
before the day the current fair market value of the securities is being
determined;

(iii) if at any time the Common Stock is not listed on any securities exchange
or quoted in the

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NASDAQ System or the over-the-counter market, the current fair market value of
Preferred Stock shall be the product of (x) the highest price per share which
the Company could obtain from a willing buyer (not a current employee or
director) for shares of Common Stock sold by the Company, from authorized but
unissued shares, as determined in good faith by its Board of Directors and (y)
the number of shares of Common Stock into which each share of Preferred Stock is
convertible at the time of such exercise or such earlier time as all outstanding
share of the Company's Preferred Stock convert into shares of Common Stock;
unless the Company shall become subject to a merger, acquisition or other
consolidation pursuant to which the Company is not the surviving party, in which
case the fair market value of Preferred Stock shall be deemed to be the value
received by the holders of the Company's Preferred Stock on a common equivalent
basis pursuant to such merger or acquisition.

Upon partial exercise by either cash or Net Issuance, the Company shall promptly
issue an amended Warrant Agreement representing the remaining number of shares
purchasable hereunder. All other terms and conditions of such amended Warrant
Agreement shall be identical to those contained herein, including, but not
limited to the Effective Date hereof.

4.   RESERVATION OF SHARES.

(a)  During the term of this Warrant Agreement, the Company will at all times
have authorized and reserved a sufficient number of shares of its Preferred
Stock to provide for the exercise of the rights to purchase Preferred Stock as
provided for herein.

(b)  Registration or Listing. If any shares of Preferred Stock required to be
reserved hereunder require registration with or approval of any governmental
authority under any Federal or State law (other than any registration under the
Securities Act of 1933, as amended ("1933 Act"), as then in effect, or any
similar Federal statute then enforced, or any state securities law, required by
reason of any transfer involved in such conversion), or listing on any domestic
securities exchange, before such shares may be issued upon conversion, the
Company will, at its expense and as expeditiously as possible, use its best
efforts to cause such shares to be duly registered, listed or approved for
listing on such domestic securities exchange, as the case may be.

5.   NO FRACTIONAL SHARES OR SCRIP.

No fractional shares or scrip representing fractional shares shall be issued
upon the exercise of the Warrant, but in lieu of such fractional shares the
Company shall make a cash payment therefor upon the basis of the Exercise Price
then in effect.

6.   NO RIGHTS AS SHAREHOLDER.

This Warrant Agreement does not entitle the Warrantholder to any voting rights
or other rights as a shareholder of the Company prior to the exercise of the
Warrant.

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7.   WARRANTHOLDER REGISTRY.

The Company shall maintain a registry showing the name and address of the
registered holder of this Warrant Agreement.

8.   ADJUSTMENT RIGHTS.

The purchase price per share and the number of shares of Preferred Stock
purchasable hereunder are subject to adjustment, as follows:

(a)  Merger and Sale of Assets. If at any time there shall be a capital
reorganization of the shares of the Company's stock (other than a combination,
reclassification, exchange or subdivision of shares otherwise provided for
herein), or a merger or consolidation of the Company with or into another
corporation whether or not the Company is the surviving corporation other than a
Termination Event, as defined in Section 2 hereof, or the sale of all or
substantially all of the Company's properties and assets to any other person
other than a Termination Event (hereinafter referred to as a "Merger Event"),
then, as a part of such Merger Event, lawful provision shall be made so that the
Warrantholder shall thereafter be entitled to receive, upon exercise of the
Warrant, the number of shares of preferred stock or other securities of the
successor corporation resulting from such Merger Event, equivalent in value to
that which would have been issuable if Warrantholder had exercised this Warrant
immediately prior to the Merger Event. In any such case, appropriate adjustment
(as determined in good faith by the Company's Board of Directors) shall be made
in the application of the provisions of this Warrant Agreement with respect to
the rights and interest of the Warrantholder after the Merger Event to the end
that the provisions of this Warrant Agreement (including adjustments of the
Exercise Price and number of shares of Preferred Stock purchasable) shall be
applicable to the greatest extent possible.

(b)  Reclassification of Shares. If the Company at any time shall, by
combination, reclassification, exchange or subdivision of securities or
otherwise, change any of the securities as to which purchase rights under this
Warrant Agreement exist into the same or a different number of securities of any
other class or classes, this Warrant Agreement shall thereafter represent the
right to acquire such number and kind of securities as would have been issuable
as the result of such change with respect to the securities which were subject
to the purchase rights under this Warrant Agreement immediately prior to such
combination, reclassification, exchange, subdivision or other change.

(c)  Subdivision or Combination of Shares. If the Company at any time shall
combine or subdivide its Preferred Stock, the Exercise Price shall be
proportionately decreased in the case of a subdivision, or proportionately
increased in the case of a combination.

(d)  Stock Dividends. If the Company at any time shall pay a dividend payable
in, or make any other distribution (except any distribution specifically
provided for in the foregoing subsections (a) or (b)) of the Company's Preferred
Stock, then the Exercise Price shall be adjusted, from and after the record date
of such dividend or distribution, to that price determined by multiplying the
Exercise Price in effect immediately prior to such record date by a fraction (i)
the numerator of which shall be the total number of all shares of the Company's
Preferred Stock outstanding immediately prior to such dividend or distribution,
and (ii) the denominator of which

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shall be the total number of all shares of the Company's Preferred Stock
outstanding immediately after such dividend or distribution. The Warrantholder
shall thereafter be entitled to purchase, at the Exercise Price resulting from
such adjustment, the number of shares of Preferred Stock (calculated to the
nearest whole share) obtained by multiplying the Exercise Price in effect
immediately prior to such adjustment by the number of shares of Preferred Stock
issuable upon the exercise hereof immediately prior to such adjustment and
dividing the product thereof by the Exercise Price resulting from such
adjustment.

(e)  Antidilution Rights. Antidilution rights applicable to the Preferred Stock
purchasable hereunder are as set forth in the Company's Certificate of
Incorporation, as amended through the Effective Date, a true and complete copy
of which is attached hereto as Exhibit IV (the "Charter"). The Company shall
promptly provide the Warrantholder with any restatement, amendment, modification
or waiver of the Charter. The Preferred Stock purchasable hereunder shall have
the benefit of the same antidilution rights applicable to such Preferred Stock
as designated in the Company's Charter, and the Company shall provide
Warrantholder with all notices and information at the time and to the extent it
is required to do so to the holders of the Preferred Stock.

(f)  Notice of Adjustments. If: (i) the Company shall declare any dividend or
distribution upon its stock, whether in cash, property, stock or other
securities; (ii) the Company shall offer for subscription prorata to the holders
of any class of its Preferred or other convertible stock on the basis of their
ownership thereof any additional shares of stock of any class or other rights;
(iii) there shall be any Merger Event; (iv) there shall be an initial public
offering; or (v) there shall be any voluntary dissolution, liquidation or
winding up of the Company; then, in connection with each such event, the Company
shall send to the Warrantholder: (A) prior written notice no later than the date
that such notice is provided to the Company's shareholders of the date on which
the books of the Company shall close or a record shall be taken for such
dividend, distribution, subscription rights (specifying the date on which the
holders of Preferred Stock shall be entitled thereto) or for determining rights
to vote in respect of such Merger Event, dissolution, liquidation or winding up;
(B) in the case of any such Merger Event, dissolution, liquidation or winding
up, prior written notice no later than the date that such notice is provided to
the Company's shareholders of the date when the same shall take place (and
specifying the date on which the holders of Preferred Stock shall be entitled to
exchange their Preferred Stock for securities or other property deliverable upon
such Merger Event, dissolution, liquidation or winding up); and (C) in the case
of a public offering, the Company shall give the Warrantholder prior written
notice no later than the date that such notice is provided to the Company's
shareholders.

Each such written notice shall set forth, in reasonable detail, (i) the event
requiring the adjustment, (ii) the amount of the adjustment, (iii) the method by
which such adjustment was calculated, (iv) the Exercise Price, and (v) the
number of shares subject to purchase hereunder after giving effect to such
adjustment, and shall be given by first class mail, postage prepaid, addressed
to the Warrantholder, at the address as shown on the books of the Company.

(g)  Timely Notice. Failure to timely provide such notice required by subsection
(f) above shall entitle Warrantholder to retain the benefit of the applicable
notice period notwithstanding

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anything to the contrary contained in any insufficient notice received by
Warrantholder. The notice period shall begin on the date Warrantholder actually
receives a written notice containing all the information specified above.

9.   REPRESENTATIONS. WARRANTIES AND COVENANTS OF THE COMPANY.

(a)  Reservation of Preferred Stock. The Preferred Stock issuable upon exercise
of the Warrantholder's rights has been duly and validly reserved and, when
issued in accordance with the provisions of this Warrant Agreement, will be
validly issued, fully paid and non-assessable, and will be free of any taxes,
liens, charges or encumbrances of any nature whatsoever; provided, however, that
the Preferred Stock issuable pursuant to this Warrant Agreement may be subject
to restrictions on transfer under state and/or Federal securities laws. The
Company has made available to the Warrantholder true, correct and complete
copies of its Charter and Bylaws, as amended. The issuance of certificates for
shares of Preferred Stock upon exercise of the Warrant Agreement shall be made
without charge to the Warrantholder for any issuance tax in respect thereof, or
other cost incurred by the Company in connection with such exercise and the
related issuance of shares of Preferred Stock. The Company shall not be required
to pay any tax which may be payable in respect of any transfer involved and the
issuance and delivery of any certificate in a name other than that of the
Warrantholder.

(b)  Due Authority. The execution and delivery by the Company of this Warrant
Agreement and the performance of all obligations of the Company hereunder,
including the issuance to Warrantholder of the right to acquire the shares of
Preferred Stock, have been duly authorized by all necessary corporate action on
the part of the Company, and the Leases and this Warrant Agreement are not
inconsistent with the Company's Charter or Bylaws, to the Company's knowledge,
do not contravene any law or governmental rule, regulation or order applicable
to it, do not and will not contravene any provision of, or constitute a default
under, any indenture, mortgage, contract or other instrument to which it is a
party or by which it is bound, and the Leases and this Warrant Agreement
constitute legal, valid and binding agreements of the Company, enforceable in
accordance with their respective terms , except as limited by applicable
bankruptcy, insolvency, reorganization, moratorium and other laws of general
application affecting enforcement of creditor's rights generally and (ii) as
limited by laws relating to the availability of specific performance, injunctive
relief or other equitable remedies.

(c)  Consents and Approvals. No consent or approval of, giving of notice to,
registration with, or taking of any other action in respect of any state,
Federal or other governmental authority or agency is required with respect to
the execution, delivery and performance by the Company of its obligations under
this Warrant Agreement, except for any filing of notices pursuant to Regulation
D under the 1933 Act and any filing required by applicable state securities law,
which filings will be effective by the time required thereby.

(d)  Issued Securities. All issued and outstanding shares of Common Stock,
Preferred Stock or any other securities of the Company have been duly authorized
and validly issued and are fully paid and nonassessable. All outstanding shares
of Common Stock, Preferred Stock and any other securities were issued in full
compliance with all Federal and state securities laws. In addition the
authorized capital of the Company consists of the following as of February 24,
2000:

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(i)   Preferred Stock. Forty-nine million three hundred eighty-two thousand
seven hundred sixty-nine (49,382,769) shares of Preferred Stock (the "Preferred
Stock"), of which eleven million one hundred sixty thousand (11,160,000) shares
have been designated as Series A Preferred Stock, all of which are issued and
outstanding, six million two hundred twelve thousand two hundred fifty-nine
(6,212,259) shares have been designated Series B-1 Preferred Stock (the "Series
B-1 Preferred Stock"), all of which are issued and outstanding, nine million
eight hundred ten thousand five hundred ten (9,810,510) shares have been
designated Series B-2 Preferred Stock (the "Series B-2 Preferred Stock"), nine
million seven hundred thirty-two thousand five hundred ten (9,732,510) of which
are issued and outstanding, twelve million six hundred thousand (12,600,000)
shares have been designated Series C Preferred Stock (the "Series C Preferred
Stock"), twelve million ninety-eight thousand six hundred sixty-four
(12,098,664) of which were issued or outstanding and nine million six hundred
thousand (9,600,000) shares have been designated Series D Preferred Stock (the
"Series D Preferred Stock"), nine million ninety-three thousand eight hundred
forty-three (9,093,843) of which were issued and outstanding immediately prior
to the Closing.

(ii)  Common Stock. Ninety million (90,000,000) shares of Common Stock ("Common
Stock"), of which six million four hundred ten thousand five hundred forty-one
(6,410,541) shares are issued and outstanding.

(iii) Except for (A) the conversion privileges of the Series A, Series B-1,
Series B-2, Series C and Series D Preferred Stock, (B) the rights provided in
Section 2.4 of the Rights Agreement (as defined below), and (C) currently
outstanding options to purchase one million three hundred nine thousand one
(1,309,001) shares of the Company's Common Stock, there are not outstanding any
options, warrants, rights (including conversion or preemptive rights) or
agreements for the purchase or acquisition from the Company of any shares of its
capital stock. The Company has reserved two million one hundred fifty nine
thousand one hundred forty seven (2,159,147) shares of its Common Stock for
purchase upon exercise of options to be granted in the future under the
Company's 1997 Stock Plan.

(e)   Other Commitments to Register Securities. Except as set forth in this
Warrant Agreement and in that certain Amended and Restated Investors Rights
Agreement (the "Rights Agreement") dated as of November 10, 1999 by and between
the Company and the Founders and the Investors (as defined therein), the Company
is not, pursuant to the terms of any other agreement currently in existence,
under any obligation to register under the 1933 Act any of its presently
outstanding securities or any of its securities which may hereafter be issued.

(f)   Exempt Transaction. Subject to the accuracy of the Warrantholder's
representations in Section 10 hereof, the issuance of the Preferred Stock upon
exercise of this Warrant will constitute a transaction exempt from (i) the
registration requirements of Section 5 of the 1933 Act, in reliance upon Section
4(2) thereof, and (ii) the qualification requirements of the applicable state
securities laws.

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10.  REPRESENTATIONS AND COVENANTS OF THE WARRANTHOLDER.

This Warrant Agreement has been entered into by the Company in reliance upon the
following representations and covenants of the Warrantholder:

(a)  Investment Purpose. The right to acquire Preferred Stock or the Preferred
Stock issuable upon exercise of the Warrantholder's rights contained herein or
Common Stock issuable upon conversion thereof will be acquired for investment
and not with a view to the sale or distribution of any part thereof, and the
Warrantholder has no present intention of selling or engaging in any public
distribution of the same except pursuant to a registration or exemption.

(b)  Private Issue. The Warrantholder understands (i) that the Preferred Stock
issuable upon exercise of this Warrant (or Common Stock issuable upon conversion
thereof) is not registered under the 1933 Act or qualified under applicable
state securities laws on the ground that the issuance contemplated by this
Warrant Agreement will be exempt from the registration and qualifications
requirements thereof, and (ii) that the Company's reliance on such exemption is
predicated on the representations set forth in this Section 10.

(c)  Disposition of Warrantholder's Rights. In no event will the Warrantholder
make a disposition of any of its rights to acquire Preferred Stock or Preferred
Stock issuable upon exercise of such rights (or Common Stock issuable upon
conversion thereof) unless and until (i) it shall have notified the Company of
the proposed disposition, and (ii) if requested by the Company, it shall have
furnished the Company with an opinion of counsel (which counsel may either be
inside or outside counsel to the Warrantholder) satisfactory to the Company and
its counsel to the effect that (A) appropriate action necessary for compliance
with the 1933 Act has been taken, or (B) an exemption from the registration
requirements of the 1933 Act is available. Notwithstanding the foregoing, the
restrictions imposed upon the transferability of any of its rights to acquire
Preferred Stock or Preferred Stock issuable on the exercise of such rights (or
Common Stock issuable upon conversion thereof) do not apply to transfers from
the beneficial owner of any of the aforementioned securities to its nominee or
from such nominee to its beneficial owner, and shall terminate as to any
particular share of Preferred Stock when (1) such security shall have been
effectively registered under the 1933 Act and sold by the holder thereof in
accordance with such registration or (2) such security shall have been sold
without registration in compliance with Rule 144 under the 1933 Act, or (3) a
letter shall have been issued to the Warrantholder at its request by the staff
of the Securities and Exchange Commission or a ruling shall have been issued to
the Warrantholder at its request by such Commission stating that no action shall
be recommended by such staff or taken by such Commission, as the case may be, if
such security is transferred without registration under the 1933 Act in
accordance with the conditions set forth in such letter or ruling and such
letter or ruling specifies that no subsequent restrictions on transfer are
required. Whenever the restrictions imposed hereunder shall terminate, as
hereinabove provided, the Warrantholder or holder of a share of Preferred Stock
then outstanding (or Common Stock issuable upon conversion thereof) as to which
such restrictions have terminated shall be entitled to receive from the Company,
without expense to such holder, one or more new certificates for the Warrant or
for such shares of Preferred Stock (or Common Stock issuable upon conversion
thereof) not bearing any restrictive legend.

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(d)  Financial Risk. The Warrantholder has such knowledge and experience in
financial and business matters as to be capable of evaluating the merits and
risks of its investment, and has the ability to bear the economic risks of its
investment.

(e)  Risk of No Registration. The Warrantholder understands that if the Company
does not register with the Securities and Exchange Commission pursuant to
Section 12 of the 1934 Act (the "1934 Act"), or file reports pursuant to Section
15(d), of the 1934 Act, or if a registration statement covering the securities
under the 1933 Act is not in effect when it desires to sell (i) the rights to
purchase Preferred Stock pursuant to this Warrant Agreement, or (ii) the
Preferred Stock issuable upon exercise of the right to purchase (or Common Stock
issuable upon conversion thereof) it may be required to hold such securities for
an indefinite period. The Warrantholder also understands that any sale of its
rights of the Warrantholder to purchase Preferred Stock or Preferred Stock (or
Common Stock issuable upon conversion thereof) which might be made by it in
reliance upon Rule 144 under the 1933 Act may be made only in accordance with
the terms and conditions of that Rule.

(f)  Accredited Investor. Warrantholder is an "accredited investor" within the
meaning of the Securities and Exchange Rule 501 of Regulation D, as presently in
effect.

11.  TRANSFERS.

Subject to the terms and conditions contained in Section 10 hereof, this Warrant
Agreement and all rights hereunder are transferable in whole or in part by the
Warrantholder and any successor transferee, provided, however, in no event shall
the number of transfers of the rights and interests in all of the Warrants
exceed three (3) transfers and in all events shall the transferee be subject to
the obligations hereunder. The transfer shall be recorded on the books of the
Company upon receipt by the Company of a notice of transfer in the form attached
hereto as Exhibit III (the "Transfer Notice"), at its principal offices and the
payment to the Company of all transfer taxes and other governmental charges
imposed on such transfer.

12.  MARKET STANDOFF.

Warrantholder hereby agrees that, during the period of duration specified by the
Company and an underwriter of Common Stock or other securities of the Company,
following the effective date of a registration statement of the Company filed
under the Act, it shall not, to the extent requested by the Company and such
underwriter, directly or indirectly sell, offer to sell, contract to sell
(including, without limitation, any short sale), grant any option to purchase or
otherwise transfer or dispose of (other than to donees who agree to be similarly
bound) any securities of the Company held by it immediately prior to the
effective date of such registration statement, except Common Stock included in
such registration; provided, however, that:

(a)  such agreement shall be applicable only to the first such registration
statement of the Company that covers Common Stock (or other securities) to be
sold on its behalf to the public in an underwritten offering;

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(b)  all officers and directors of the Company and all other persons with
registration rights (whether or not pursuant to this Agreement) enter into
similar agreements; and

(c)  such market stand-off time period shall not exceed one hundred eighty (180)
days.

In order to enforce the foregoing covenant, the Company may impose stop-transfer
instructions with respect to the Company's securities held by the Warrantholder
(and the shares or securities of every other person subject to the foregoing
restriction) until the end of such period.

13.  MISCELLANEOUS.

(a)  Effective Date. The provisions of this Warrant Agreement shall be construed
and shall be given effect in all respects as if it had been executed and
delivered by the Company on the date hereof. This Warrant Agreement shall be
binding upon any successors or assigns of the Company and Warrantholder.

(b)  Attorney's Fees. In any litigation, arbitration or court proceeding between
the Company and the Warrantholder relating hereto, the prevailing party shall be
entitled to attorneys' fees and expenses and all costs of proceedings incurred
in enforcing this Warrant Agreement.

(c)  Governing Law. This Warrant Agreement shall be governed by and construed
for all purposes under and in accordance with the laws of the State of Texas.

(d)  Counterparts. This Warrant Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

(e)  Notices. Any notice required or permitted hereunder shall be given in
writing and shall be deemed effectively given upon personal delivery, facsimile
transmission (provided that the original is sent by personal delivery or mail as
hereinafter set forth) or seven (7) days after deposit in the United States
mail, by registered or certified mail, addressed (i) to the Warrantholder at
6111 North River Road, Rosemont, Illinois 60018, Attention: Venture Lease
Administration, cc: Legal Department, Attention.: General Counsel, (and/or, if
by facsimile, (847)518-5465 and (847)518-5088) and (ii) to the Company at 1155
East Collins Blvd. Richardson, TX 75081, Attention: Chief Financial Officer
(and/or if by facsimile, (972)238-1477) or at such other address as any such
party may subsequently designate by written notice to the other party.

(f)  Remedies. In the event of any default hereunder, the non-defaulting party
may proceed to protect and enforce its rights either by suit in equity and/or by
action at law, including but not limited to an action for damages as a result of
any such default, and/or an action for specific performance for any default
where Warrantholder will not have an adequate remedy at law and where damages
will not be readily ascertainable. The Company expressly agrees that it shall
not oppose an application by the Warrantholder or any other person entitled to
the benefit of this

                                       11
<PAGE>

Agreement requiring specific performance of any or all provisions hereof or
enjoining the Company from continuing to commit any such breach of this Warrant
Agreement.

(g)  No Impairment of Rights. The Company will not, by amendment of its Charter
or through any other means, avoid or seek to avoid the observance or performance
of any of the terms of this Warrant, but will at all times in good faith assist
in the carrying out of all such terms and in the taking of all such actions as
may be necessary or appropriate in order to protect the rights of the
Warrantholder against impairment. The foregoing notwithstanding, the Company
shall not be deemed to have impaired the Warrantholder's rights hereunder if it
amends its Charter, or the holders of the Preferred Stock waive rights
thereunder or if the holders of Preferred Stock elect to convert all outstanding
shares of the Company into Common Stock, in a manner that does not affect the
Warrantholder in a manner different from the effect that such amendments or
waivers or election have on the rights of the holders of the Preferred Stock.

(h)  Survival. The representations, warranties, covenants and conditions of the
respective parties contained herein or made pursuant to this Warrant Agreement
shall survive the execution and delivery of this Warrant Agreement.

(i)  Severability. In the event any one or more of the provisions of this
Warrant Agreement shall for any reason be held invalid, illegal or
unenforceable, the remaining provisions of this Warrant Agreement shall be
unimpaired, and the invalid, illegal or unenforceable provision shall be
replaced by a mutually acceptable valid, legal and enforceable provision, which
comes closest to the intention of the parties underlying the invalid, illegal or
unenforceable provision.

(j)  Amendments. Any provision of this Warrant Agreement may be amended or
waived by a written instrument signed by the Company and by the Warrantholder.

(k)  Additional Documents. The Company, upon execution of this Warrant
Agreement, shall provide the Warrantholder with certified resolutions with
respect to the representations, warranties and covenants set forth in
subparagraphs (a) through (f) of Section 9 above.

                                       12
<PAGE>

IN WITNESS WHEREOF, the parties hereto have caused this Warrant Agreement to be
executed by its officers thereunto duly authorized as of the Effective Date.

Company:  CHORUM TECHNOLOGIES INC.

By:               /s/ Kent Coker
    ---------------------------------------

Title:   CFO
       ------------------------------------

Warrantholder: COMDISCO, INC.

By:
    ---------------------------------------

Title:
       ____________________________________

                                       13
<PAGE>

EXHIBIT I

NOTICE OF EXERCISE

To: ____________________________________

(1)  The undersigned Warrantholder hereby elects to purchase ________________
shares of the Series __ Preferred Stock of ______________, pursuant to the terms
of the Warrant Agreement dated the ___ day of ____________ 20__ (the "Warrant
Agreement") between __________________ and the Warrantholder, and tenders
herewith payment of the purchase price for such shares in full, together with
all applicable transfer taxes, if any.

(2)  In exercising its rights to purchase the Series __ Preferred Stock of
______________________, the undersigned hereby confirms and acknowledges the
investment representations and warranties made in Section 10 of the Warrant
Agreement.

(3)  Please issue a certificate or certificates representing said shares of
     Series __ Preferred Stock in the name of the undersigned or in such other
     name as is specified below.

______________________________
(Name)

______________________________
(Address)

Warrantholder: COMDISCO, INC.

By: __________________________

Title: _______________________

Date: ________________________

                                       14
<PAGE>

EXHIBIT II

ACKNOWLEDGMENT OF EXERCISE

     The undersigned ________________, hereby acknowledge receipt of the "Notice
of Exercise" from Comdisco, Inc., to purchase ________________ shares of the
Series __ Preferred Stock of ________________, pursuant to the terms of the
Warrant Agreement, and further acknowledges that _____________ shares remain
subject to purchase under the terms of the Warrant Agreement.

     Company:

     By: ______________________________

     Title: ___________________________

     Date: ____________________________

                                       15<PAGE>

                                                                    EXHIBIT 10.1

                           INDEMNIFICATION AGREEMENT

          THIS AGREEMENT (the "Agreement") is made and entered into as of
     _____________, 2000, between Chorum Technologies, Inc., a Delaware
     corporation ("the Company"), and ("Indemnitee").

          WITNESSETH THAT:

          WHEREAS, Indemnitee performs a valuable service for the Company;

          WHEREAS, the Board of Directors of the Company has adopted Bylaws (the
     "Bylaws") providing for the indemnification of the officers and directors
     of the Company to the maximum extent authorized by Section 145 of the
     Delaware General Corporation Law, as amended ("Law");

          WHEREAS, the Bylaws and the Law, by their nonexclusive nature, permit
     contracts between the Company and the officers or directors of the Company
     with respect to indemnification of such officers or directors;

          WHEREAS, in accordance with the authorization as provided by the Law,
     the Company may purchase and maintain a policy or policies of directors'
     and officers' liability insurance ("D & O Insurance"), covering certain
     liabilities which may be incurred by its officers or directors in the
     performance of their obligations to the Company; and

          WHEREAS, in recognition of past services and in order to induce
     Indemnitee to continue to serve as an officer or director of the Company,
     the Company has determined and agreed to enter into this contract with
     Indemnitee;

          NOW, THEREFORE, in consideration of Indemnitee's service as an officer
     or director after the date hereof, the parties hereto agree as follows:

          1.  Indemnity of Indemnitee. The Company hereby agrees to hold
              -----------------------
     harmless and indemnify Indemnitee to the full extent authorized or
     permitted by the provisions of the Law, as such may be amended from time to
     time, and Article VII, Section 6 of the Bylaws, as such may be amended. In
     furtherance of the foregoing indemnification, and without limiting the
     generality thereof:

              (a) Proceedings Other Than Proceedings by or in the Right of the
                  ------------------------------------------------------------
     Company. Indemnitee shall be entitled to the rights of indemnification
     -------
     provided in this Section l(a) if, by reason of his Corporate Status (as
     hereinafter defined), he is, or is threatened to be made, a party to or
     participant in any Proceeding (as hereinafter defined) other than a
     Proceeding by or in the right of the Company. Pursuant to this Section
     1(a), Indemnitee shall be indemnified against all Expenses (as hereinafter
     defined), judgments, penalties, fines and amounts paid in settlement
     actually and reasonably incurred by him or on his behalf in connection with
     such Proceeding or any claim, issue or matter therein, if he acted in good
     faith and in a manner he reasonably believed to be in or not opposed to the
     best interests of the
<PAGE>

     Company and, with respect to any criminal Proceeding, had no reasonable
     cause to believe his conduct was unlawful.

               (b)  Proceedings by or in the Right of the Company. Indemnitee
                    ---------------------------------------------
     shall be entitled to the rights of indemnification provided in this Section
     1(b) if, by reason of his Corporate Status, he is, or is threatened to be
     made, a party to or participant in any Proceeding brought by or in the
     right of the Company. Pursuant to this Section 1(b), Indemnitee shall be
     indemnified against all Expenses actually and reasonably incurred by him or
     on his behalf in connection with such Proceeding if he acted in good faith
     and in a manner he reasonably believed to be in or not opposed to the best
     interests of the Company; provided, however, that, if applicable law so
     provides, no indemnification against such Expenses shall be made in respect
     of any claim, issue or matter in such Proceeding as to which Indemnitee
     shall have been adjudged to be liable to the Company unless and to the
     extent that the Court of Chancery of the State of Delaware shall determine
     that such indemnification may be made.

               (c)  Indemnification for Expenses of a Party Who is Wholly or
                    --------------------------------------------------------
     Partly Successful. Notwithstanding any other provision of this Agreement,
     -----------------
     to the extent that Indemnitee is, by reason of his Corporate Status, a
     party to and is successful, on the merits or otherwise, in any Proceeding,
     he shall be indemnified to the maximum extent permitted by law against all
     Expenses actually and reasonably incurred by him or on his behalf in
     connection therewith. If Indemnitee is not wholly successful in such
     Proceeding but is successful, on the merits or otherwise, as to one or more
     but less than all claims, issues or matters in such Proceeding, the Company
     shall indemnify Indemnitee against all Expenses actually and reasonably
     incurred by him or on his behalf in connection with each successfully
     resolved claim, issue or matter. For purposes of this Section and without
     limitation, the termination of any claim, issue or matter in such a
     Proceeding by dismissal, with or without prejudice, shall be deemed to be a
     successful result as to such claim, issue or matter.

          2. Additional Indemnity. In addition to, and without regard to any
             --------------------
     limitations on, the indemnification provided for in Section 1, the Company
     shall and hereby does indemnify and hold harmless Indemnitee against all
     Expenses, judgments, penalties, fines and amounts paid in settlement
     actually and reasonably incurred by him or on his behalf if, by reason of
     his Corporate Status, he is, or is threatened to be made, a party to or
     participant in any Proceeding (including a Proceeding by or in the right of
     the Company), including, without limitation, all liability arising out of
     the negligence or active or passive wrongdoing of Indemnitee. The only
     limitation that shall exist upon the Company's obligations pursuant to this
     Agreement shall be that the Company shall not be obligated to make any
     payment to Indemnitee that is finally determined (under the procedures, and
     subject to the presumptions, set forth in Sections 6 and 7 hereof) to be
     unlawful under Delaware law.

          3. Contribution in the Event of Joint Liability.
             --------------------------------------------

             (a) Whether or not the indemnification provided in Sections 1 and 2
     hereof is available, in respect of any threatened, pending or completed
     action, suit or proceeding in which Company is jointly liable with
     Indemnitee (or would be if joined in such action, suit or proceeding),
     Company shall pay, in the first instance, the entire amount of any judgment
     or

                                       2
<PAGE>

     settlement of such action, suit or proceeding without requiring Indemnitee
     to contribute to such payment and Company hereby waives and relinquishes
     any right of contribution it may have against Indemnitee. Company shall not
     enter into any settlement of any action, suit or proceeding in which
     Company is jointly liable with Indemnitee (or would be if joined in such
     action, suit or proceeding) unless such settlement provides for a full and
     final release of all claims asserted against Indemnitee.

               (b)  Without diminishing or impairing the obligations of the
     Company set forth in the preceding subparagraph, if, for any reason,
     Indemnitee shall elect or be required to pay all or any portion of any
     judgment or settlement in any threatened, pending or completed action, suit
     or proceeding in which Company is jointly liable with Indemnitee (or would
     be if joined in such action, suit or proceeding), Company shall contribute
     to the amount of expenses (including attorneys' fees), judgments, fines and
     amounts paid in settlement actually and reasonably incurred and paid or
     payable by Indemnitee in proportion to the relative benefits received by
     the Company and all officers, directors or employees of the Company other
     than Indemnitee who are jointly liable with Indemnitee (or would be if
     joined in such action, suit or proceeding), on the one hand, and
     Indemnitee, on the other hand, from the transaction from which such action,
     suit or proceeding arose; provided, however, that the proportion determined
     on the basis of relative benefit may, to the extent necessary to conform to
     law, be further adjusted by reference to the relative fault of Company and
     all officers, directors or employees of the Company other than Indemnitee
     who are jointly liable with Indemnitee (or would be if joined in such
     action, suit or proceeding), on the one hand, and Indemnitee, on the other
     hand, in connection with the events that resulted in such expenses,
     judgments, fines or settlement amounts, as well as any other equitable
     considerations which the law may require to be considered. The relative
     fault of Company and all officers, directors or employees of the Company
     other than Indemnitee who are jointly liable with Indemnitee (or would be
     if joined in such action, suit or proceeding), on the one hand, and
     Indemnitee, on the other hand, shall be determined by reference to, among
     other things, the degree to which their actions were motivated by intent to
     gain personal profit or advantage, the degree to which their liability is
     primary or secondary, and the degree to which their conduct is active or
     passive.

               (c)  Company hereby agrees to fully indemnify and hold Indemnitee
     harmless from any claims of contribution which may be brought by officers,
     directors or employees of the Company other than Indemnitee who may be
     jointly liable with Indemnitee.

          4.   Indemnification for Expenses of a Witness. Notwithstanding any
               -----------------------------------------
     other provision of this Agreement, to the extent that Indemnitee is, by
     reason of his Corporate Status, a witness in any Proceeding to which
     Indemnitee is not a party, he shall be indemnified against all Expenses
     actually and reasonably incurred by him or on his behalf in connection
     therewith.

          5.   Advancement of Expenses. Notwithstanding any other provision of
               -----------------------
     this Agreement, the Company shall advance all Expenses incurred by or on
     behalf of Indemnitee in connection with any Proceeding by reason of
     Indemnitee's Corporate Status within ten (10) days after the receipt by the
     Company of a statement or statements from Indemnitee requesting such
     advance or advances from time to time, whether prior to or after final
     disposition of such Proceeding. Such statement or statements shall
     reasonably evidence the Expenses incurred by

                                       3
<PAGE>

     Indemnitee and shall include or be preceded or accompanied by an
     undertaking by or on behalf of Indemnitee to repay any Expenses advanced if
     it shall ultimately be determined that Indemnitee is not entitled to be
     indemnified against such Expenses. Any advances and undertakings to repay
     pursuant to this Section 5 shall be unsecured and interest free.
     Notwithstanding the foregoing, the obligation of the Company to advance
     Expenses pursuant to this Section 5 shall be subject to the condition that,
     if, when and to the extent that the Company determines that Indemnitee
     would not be permitted to be indemnified under applicable law, the Company
     shall be entitled to be reimbursed, within thirty (30) days of such
     determination, by Indemnitee (who hereby agrees to reimburse the Company)
     for all such amounts theretofore paid; provided, however, that if
     Indemnitee has commenced or thereafter commences legal proceedings in a
     court of competent jurisdiction to secure a determination that Indemnitee
     should be indemnified under applicable law, any determination made by the
     Company that Indemnitee would not be permitted to be indemnified under
     applicable law shall not be binding and Indemnitee shall not be required to
     reimburse the Company for any advance of Expenses until a final judicial
     determination is made with respect thereto (as to which all rights of
     appeal therefrom have been exhausted or lapsed).

               6.  Procedures and Presumptions for Determination of Entitlement
                   ------------------------------------------------------------
     to Indemnification. It is the intent of this Agreement to secure for
     ------------------
     Indemnitee rights of indemnity that are as favorable as may be permitted
     under the law and public policy of the State of Delaware. Accordingly, the
     parties agree that the following procedures and presumptions shall apply in
     the event of any question as to whether Indemnitee is entitled to
     indemnification under this Agreement:

                   (a)  To obtain indemnification (including, but not limited
     to, the advancement of Expenses and contribution by the Company) under this
     Agreement, Indemnitee shall submit to the Company a written request,
     including therein or therewith such documentation and information as is
     reasonably available to Indemnitee and is reasonably necessary to determine
     whether and to what extent Indemnitee is entitled to indemnification. The
     Secretary of the Company shall, promptly upon receipt of such a request for
     indemnification, advise the Board of Directors in writing that Indemnitee
     has requested indemnification.

                   (b)  Upon written request by Indemnitee for indemnification
     pursuant to the first sentence of Section 6(a) hereof, a determination, if
     required by applicable law, with respect to Indemnitee's entitlement
     thereto shall be made in the specific case by one of the following three
     methods, which shall be at the election of Indemnitee: (1) by a majority
     vote of the disinterested directors, even though less than a quorum, or (2)
     by independent legal counsel in a written opinion, or (3) by the
     stockholders.

                   (c)  If the determination of entitlement to indemnification
     is to be made by Independent Counsel pursuant to Section 6(b) hereof, the
     Independent Counsel shall be selected as provided in this Section 6(c). The
     Independent Counsel shall be selected by Indemnitee (unless Indemnitee
     shall request that such selection be made by the Board of Directors).
     Indemnitee or the Company, as the case may be, may, within 10 days after
     such written notice of selection shall have been given, deliver to the
     Company or to Indemnitee, as the case may be, a written objection to such
     selection; provided, however, that such objection may be asserted only on
     the ground that the Independent Counsel so selected does not meet the

                                       4
<PAGE>

     requirements of "Independent Counsel" as defined in Section 13 of this
     Agreement, and the objection shall set forth with particularity the factual
     basis of such assertion. Absent a proper and timely objection, the person
     so selected shall act as Independent Counsel. If a written objection is
     made and substantiated, the Independent Counsel selected may not serve as
     Independent Counsel unless and until such objection is withdrawn or a court
     has determined that such objection is without merit. If, within 20 days
     after submission by Indemnitee of a written request for indemnification
     pursuant to Section 6(a) hereof, no Independent Counsel shall have been
     selected and not objected to, either the Company or Indemnitee may petition
     the Court of Chancery of the State of Delaware or other court of competent
     jurisdiction for resolution of any objection which shall have been made by
     the Company or Indemnitee to the other's selection of Independent Counsel
     and/or for the appointment as Independent Counsel of a person selected by
     the court or by such other person as the court shall designate, and the
     person with respect to whom all objections are so resolved or the person so
     appointed shall act as Independent Counsel under Section 6(b) hereof. The
     Company shall pay any and all reasonable fees and expenses of Independent
     Counsel incurred by such Independent Counsel in connection with acting
     pursuant to Section 6(b) hereof, and the Company shall pay all reasonable
     fees and expenses incident to the procedures of this Section 6(c),
     regardless of the manner in which such Independent Counsel was selected or
     appointed.

               (d)  In making a determination with respect to entitlement to
     indemnification hereunder, the person or persons or entity making such
     determination shall presume that Indemnitee is entitled to indemnification
     under this Agreement if Indemnitee has submitted a request for
     indemnification in accordance with Section 6(a) of this Agreement. Anyone
     seeking to overcome this presumption shall have the burden of proof and the
     burden of persuasion, by clear and convincing evidence.

               (e)  Indemnitee shall be deemed to have acted in good faith if
     Indemnitee's action is based on the records or books of account of the
     Enterprise, including financial statements, or on information supplied to
     Indemnitee by the officers of the Enterprise in the course of their duties,
     or on the advice of legal counsel for the Enterprise or on information or
     records given or reports made to the Enterprise by an independent certified
     public accountant or by an appraiser or other expert selected with
     reasonable care by the Enterprise. In addition, the knowledge and/or
     actions, or failure to act, of any director, officer, agent or employee of
     the Enterprise shall not be imputed to Indemnitee for purposes of
     determining the right to indemnification under this Agreement. Whether or
     not the foregoing provisions of this Section 6(e) are satisfied, it shall
     in any event be presumed that Indemnitee has at all times acted in good
     faith and in a manner he reasonably believed to be in or not opposed to the
     best interests of the Company. Anyone seeking to overcome this presumption
     shall have the burden of proof and the burden of persuasion, by clear and
     convincing evidence.

               (f)  If the person, persons or entity empowered or selected under
     Section 6 to determine whether Indemnitee is entitled to indemnification
     shall not have made a determination within thirty (30) days after receipt
     by the Company of the request therefor, the requisite determination of
     entitlement to indemnification shall be deemed to have been made and
     Indemnitee shall be entitled to such indemnification, absent (i) a
     misstatement by Indemnitee of a material fact, or an omission of a material
     fact necessary to make Indemnitee's statement not

                                       5
<PAGE>

     materially misleading, in connection with the request for indemnification,
     or (ii) a prohibition of such indemnification under applicable law;
     provided, however, that such 30 day period may be extended for a reasonable
     time, not to exceed an additional fifteen (15) days, if the person, persons
     or entity making the determination with respect to entitlement to
     indemnification in good faith requires such additional time for the
     obtaining or evaluating documentation and/or information relating thereto;
     and provided, further, that the foregoing provisions of this Section 6(g)
     shall not apply if the determination of entitlement to indemnification is
     to be made by the stockholders pursuant to Section 6(b) of this Agreement
     and if (A) within fifteen (15) days after receipt by the Company of the
     request for such determination the Board of Directors or the Disinterested
     Directors, if appropriate, resolve to submit such determination to the
     stockholders for their consideration at an annual meeting thereof to be
     held within seventy five (75) days after such receipt and such
     determination is made thereat, or (B) a special meeting of stockholders is
     called within fifteen (15) days after such receipt for the purpose of
     making such determination, such meeting is held for such purpose within
     sixty (60) days after having been so called and such determination is made
     thereat.

               (g) Indemnitee shall cooperate with the person, persons or entity
     making such determination with respect to Indemnitee's entitlement to
     indemnification, including providing to such person, persons or entity upon
     reasonable advance request any documentation or information which is not
     privileged or otherwise protected from disclosure and which is reasonably
     available to Indemnitee and reasonably necessary to such determination. Any
     Independent Counsel, member of the Board of Directors, or stockholder of
     the Company shall act reasonably and in good faith in making a
     determination under the Agreement of the Indemnitee's entitlement to
     indemnification. Any costs or expenses (including attorneys' fees and
     disbursements) incurred by Indemnitee in so cooperating with the person,
     persons or entity making such determination shall be borne by the Company
     (irrespective of the determination as to Indemnitee's entitlement to
     indemnification) and the Company hereby indemnifies and agrees to hold
     Indemnitee harmless therefrom.

               (h) The Company acknowledges that a settlement or other
     disposition short of final judgment may be successful if it permits a party
     to avoid expense, delay, distraction, disruption and uncertainty. In the
     event that any action, claim or proceeding to which Indemnitee is a party
     is resolved in any manner other than by adverse judgment against Indemnitee
     (including, without limitation, settlement of such action, claim or
     proceeding with or without payment of money or other consideration) it
     shall be presumed that Indemnitee has been successful on the merits or
     otherwise in such action, suit or proceeding. Anyone seeking to overcome
     this presumption shall have the burden of proof and the burden of
     persuasion, by clear and convincing evidence.

          7.   Remedies of Indemnitee.
               ----------------------

               (a)  In the event that (i) a determination is made pursuant to
     Section 6 of this Agreement that Indemnitee is not entitled to
     indemnification under this Agreement, (ii) advancement of Expenses is not
     timely made pursuant to Section 5 of this Agreement, (iii) no determination
     of entitlement to indemnification shall have been made pursuant to Section
     6(b) of this Agreement within 90 days after receipt by the Company of the
     request for indemnification,

                                       6
<PAGE>

     (iv) payment of indemnification is not made pursuant to this Agreement
     within ten (10) days after receipt by the Company of a written request
     therefor, or (v) payment of indemnification is not made within ten (10)
     days after a determination has been made that Indemnitee is entitled to
     indemnification or such determination is deemed to have been made pursuant
     to Section 6 of this Agreement, Indemnitee shall be entitled to an
     adjudication in an appropriate court of the State of Delaware, or in any
     other court of competent jurisdiction, of his entitlement to such
     indemnification. Indemnitee shall commence such proceeding seeking an
     adjudication within 180 days following the date on which Indemnitee first
     has the right to commence such proceeding pursuant to this Section 7(a).
     The Company shall not oppose Indemnitee's right to seek any such
     adjudication.

               (b)  In the event that a determination shall have been made
     pursuant to Section 6(b) of this Agreement that Indemnitee is not entitled
     to indemnification, any judicial proceeding commenced pursuant to this
     Section 7 shall be conducted in all respects as a de novo trial, on the
     merits and Indemnitee shall not be prejudiced by reason of that adverse
     determination under Section 6(b).

               (c)  If a determination shall have been made pursuant to Section
     6(b) of this Agreement that Indemnitee is entitled to indemnification, the
     Company shall be bound by such determination in any judicial proceeding
     commenced pursuant to this Section 7, absent a prohibition of such
     indemnification under applicable law.

               (d)  In the event that Indemnitee, pursuant to this Section 7,
     seeks a judicial adjudication of his rights under, or to recover damages
     for breach of, this Agreement, or to recover under any directors' and
     officers' liability insurance policies maintained by the Company the
     Company shall pay on his behalf, in advance, any and all expenses (of the
     types described in the definition of Expenses in Section 13 of this
     Agreement) actually and reasonably incurred by him in such judicial
     adjudication, regardless of whether Indemnitee ultimately is determined to
     be entitled to such indemnification, advancement of expenses or insurance
     recovery.

               (e)  The Company shall be precluded from asserting in any
     judicial proceeding commenced pursuant to this Section 7 that the
     procedures and presumptions of this Agreement are not valid, binding and
     enforceable and shall stipulate in any such court that the Company is bound
     by all the provisions of this Agreement.

           8.  Non-Exclusivity; Survival of Rights; Insurance; Subrogation.
               -----------------------------------------------------------

               (a) The rights of indemnification as provided by this Agreement
     shall not be deemed exclusive of any other rights to which Indemnitee may
     at any time be entitled under applicable law, the certificate of
     incorporation of the Company, the Bylaws, any agreement, a vote of
     stockholders or a resolution of directors, or otherwise. No amendment,
     alteration or repeal of this Agreement or of any provision hereof shall
     limit or restrict any right of Indemnitee under this Agreement in respect
     of any action taken or omitted by such Indemnitee in his Corporate Status
     prior to such amendment, alteration or repeal. To the extent that a change
     in the Law, whether by statute or judicial decision, permits greater
     indemnification than would be

                                       7
<PAGE>

     afforded currently under the Bylaws and this Agreement, it is the intent of
     the parties hereto that Indemnitee shall enjoy by this Agreement the
     greater benefits so afforded by such change. No right or remedy herein
     conferred is intended to be exclusive of any other right or remedy, and
     every other right and remedy shall 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 right or remedy.

               (b)  To the extent that the Company maintains an insurance policy
     or policies providing liability insurance for directors, officers,
     employees, or agents or fiduciaries of the Company or of any other
     corporation, partnership, joint venture, trust, employee benefit plan or
     other enterprise which such person serves at the request of the Company,
     Indemnitee shall be covered by such policy or policies in accordance with
     its or their terms to the maximum extent of the coverage available for any
     such director, officer, employee or agent under such policy or policies.

               (c)  In the event of any payment under this Agreement, the
     Company shall be subrogated to the extent of such payment to all of the
     rights of recovery of Indemnitee, who shall execute all papers required and
     take all action necessary to secure such rights, including execution of
     such documents as are necessary to enable the Company to bring suit to
     enforce such rights.

               (d)  The Company shall not be liable under this Agreement to make
     any payment of amounts otherwise indemnifiable hereunder if and to the
     extent that Indemnitee has otherwise actually received such payment under
     any insurance policy, contract, agreement or otherwise.

          9.   Exception to Right of Indemnification. Notwithstanding any other
               -------------------------------------
     provision of this Agreement, Indemnitee shall not be entitled to
     indemnification under this Agreement with respect to any Proceeding brought
     by Indemnitee, or any claim therein, unless (a) the bringing of such
     Proceeding or making of such claim shall have been approved by the Board of
     Directors of the Company or (b) such Proceeding is being brought by the
     Indemnitee to assert, interpret or enforce his rights under this Agreement.

          10.  Duration of Agreement. All agreements and obligations of the
               ---------------------
     Company contained herein shall continue during the period Indemnitee is an
     officer or director of the Company (or is or was serving at the request of
     the Company as a director, officer, employee or agent of another
     corporation, partnership, joint venture, trust or other enterprise) and
     shall continue thereafter so long as Indemnitee shall be subject to any
     Proceeding (or any proceeding commenced under Section 7 hereof) by reason
     of his Corporate Status, whether or not he is acting or serving in any such
     capacity at the time any liability or expense is incurred for which
     indemnification can be provided under this Agreement. This Agreement shall
     be binding upon and inure to the benefit of and be enforceable by the
     parties hereto and their respective successors (including any direct or
     indirect successor by purchase, merger, consolidation or otherwise to all
     or substantially all of the business or assets of the Company), assigns,
     spouses, heirs, executors and personal and legal representatives. This
     Agreement shall continue in effect regardless of

                                       8
<PAGE>

     whether Indemnitee continues to serve as an officer or director of the
     Company or any other Enterprise at the Company's request.

               11.  Security. To the extent requested by the Indemnitee and
                    --------
     approved by the Board of Directors of the Company, the Company may at any
     time and from time to time provide security to the Indemnitee for the
     Company's obligations hereunder through an irrevocable bank line of credit,
     funded trust or other collateral. Any such security, once provided to the
     Indemnitee, may not be revoked or released without the prior written
     consent of the Indemnitee.

               12.  Enforcement.
                    -----------

                    (a)  The Company expressly confirms and agrees that it has
     entered into this Agreement and assumed the obligations imposed on it
     hereby in order to induce Indemnitee to serve as an officer or director of
     the Company, and the Company acknowledges that Indemnitee is relying upon
     this Agreement in serving as an officer or director of the Company.

                    (b)  This Agreement constitutes the entire agreement between
     the parties hereto with respect to the subject matter hereof and supersedes
     all prior agreements and understandings, oral, written and implied, between
     the parties hereto with respect to the subject matter hereof.

               13.  Definitions.  For purposes of this Agreement:
                    -----------

                    (a)  "Corporate Status" describes the status of a person who
     is or was a director, officer, employee or agent or fiduciary of the
     Company or of any other corporation, partnership, joint venture, trust,
     employee benefit plan or other enterprise which such person is or was
     serving at the express written request of the Company.

                    (b)  "Disinterested Director" means a director of the
     Company who is not and was not a party to the Proceeding in respect of
     which indemnification is sought by Indemnitee.

                    (c)  "Enterprise" shall mean the Company and any other
     corporation, partnership, joint venture, trust, employee benefit plan or
     other enterprise of which Indemnitee is or was serving at the express
     written request of the Company as a director, officer, employee, agent or
     fiduciary.

                    (d)  "Expenses" shall include all reasonable attorneys'
     fees, retainers, court costs, transcript costs, fees of experts, witness
     fees, travel expenses, duplicating costs, printing and binding costs,
     telephone charges, postage, delivery service fees, and all other
     disbursements or expenses of the types customarily incurred in connection
     with prosecuting, defending, preparing to prosecute or defend,
     investigating, participating, or being or preparing to be a witness in a
     Proceeding.

                    (e)  "Independent Counsel" means a law firm, or a member of
     a law firm, that is experienced in matters of corporation law and neither
     presently is, nor in the past

                                       9
<PAGE>

     five years has been, retained to represent: (i) the Company or Indemnitee
     in any matter material to either such party (other than with respect to
     matters concerning the Indemnitee under this Agreement, or of other
     indemnitees under similar indemnification agreements), or (ii) any other
     party to the Proceeding giving rise to a claim for indemnification
     hereunder. Notwithstanding the foregoing, the term "Independent Counsel"
     shall not include any person who, under the applicable standards of
     professional conduct then prevailing, would have a conflict of interest in
     representing either the Company or Indemnitee in an action to determine
     Indemnitee's rights under this Agreement. The Company agrees to pay the
     reasonable fees of the Independent Counsel referred to above and to fully
     indemnify such counsel against any and all Expenses, claims, liabilities
     and damages arising out of or relating to this Agreement or its engagement
     pursuant hereto.

               (f)  "Proceeding" includes any threatened, pending or completed
     action, suit, arbitration, alternate dispute resolution mechanism,
     investigation, inquiry, administrative hearing or any other actual,
     threatened or completed proceeding, whether brought by or in the right of
     the Company or otherwise and whether civil, criminal, administrative or
     investigative, in which Indemnitee was, is or will be involved as a party
     or otherwise, by reason of the fact that Indemnitee is or was a director of
     the Company, by reason of any action taken by him or of any inaction on his
     part while acting as an officer or director of the Company, or by reason of
     the fact that he is or was serving at the request of the Company as a
     director, officer, employee or agent of another corporation, partnership,
     joint venture, trust or other Enterprise; in each case whether or not he is
     acting or serving in any such capacity at the time any liability or expense
     is incurred for which indemnification can be provided under this Agreement;
     including one pending on or before the date of this Agreement; and
     excluding one initiated by an Indemnitee pursuant to Section 7 of this
     Agreement to enforce his rights under this Agreement.

          14.  Severability. If any provision or provisions of this Agreement
               ------------
     shall be held by a court of competent jurisdiction to be invalid, void,
     illegal or otherwise unenforceable for any reason whatsoever: (a) the
     validity, legality and enforceability of the remaining provisions of this
     Agreement (including without limitation, each portion of any section of
     this Agreement containing any such provision held to be invalid, illegal or
     unenforceable, that is not itself invalid, illegal or unenforceable) shall
     not in any way be affected or impaired thereby and shall remain enforceable
     to the fullest extent permitted by law; and (b) to the fullest extent
     possible, the provisions of this Agreement (including, without limitation,
     each portion of any section of this Agreement containing any such provision
     held to be invalid, illegal or unenforceable, that is not itself invalid,
     illegal or unenforceable) shall be construed so as to give effect to the
     intent manifested thereby.

          15.  Modification and Waiver. No supplement, modification, termination
               -----------------------
     or amendment of this Agreement shall be binding unless executed in writing
     by both of the parties hereto. No waiver of any of the provisions of this
     Agreement shall be deemed or shall constitute a waiver of any other
     provisions hereof (whether or not similar) nor shall such waiver constitute
     a continuing waiver.

          16.  Notice By Indemnitee. Indemnitee agrees promptly to notify the
               --------------------
     Company in writing upon being served with any summons, citation, subpoena,
     complaint, indictment,

                                      10
<PAGE>

     information or other document relating to any Proceeding or matter which
     may be subject to indemnification covered hereunder. The failure to so
     notify the Company shall not relieve the Company of any obligation which it
     may have to the Indemnitee under this Agreement or otherwise unless and
     only to the extent that such failure or delay materially prejudices the
     Company.

          17.  Notices. All notices, requests, demands and other communications
               -------
     hereunder shall be in writing and shall be deemed to have been duly given
     if (i) delivered by hand and receipted for by the party to whom said notice
     or other communication shall have been directed, or (ii) mailed by
     certified or registered mail with postage prepaid, on the third business
     day after the date on which it is so mailed:

               (a)  If to Indemnitee, to the address set forth below Indemnitee
     signature hereto.

               (b)  If to the Company, to:

                    Chorum Technologies, Inc.
                    1303 East Arapaho Road
                    Richardson, Texas  75081

     or to such other address as may have been furnished to Indemnitee by the
     Company or to the Company by Indemnitee, as the case may be.

          18.  Identical Counterparts. This Agreement may be executed in one or
               ----------------------
     more counterparts, each of which shall for all purposes be deemed to be an
     original but all of which together shall constitute one and the same
     Agreement. Only one such counterpart signed by the party against whom
     enforceability is sought needs to be produced to evidence the existence of
     this Agreement.

          19.  Headings. The headings of the paragraphs of this Agreement are
               --------
     inserted for convenience only and shall not be deemed to constitute part of
     this Agreement or to affect the construction thereof.

          20.  Governing Law. The parties agree that this Agreement shall be
               -------------
     governed by, and construed and enforced in accordance with, the laws of the
     State of Delaware without application of the conflict of laws principles
     thereof.

          21.  Gender. Use of the masculine pronoun shall be deemed to include
               ------
     usage of the feminine pronoun where appropriate.

          22.  Coverage of Certain Investors. If a partnership that is an
               -----------------------------
     investor in the Company ("Investor") is or is threatened to be made a party
     to or a participant in a Proceeding and (a) the Indemnitee also is or is
     threatened to be made a party to or participant in that same Proceeding,
     (b) the Indemnitee is a general partner (or general partner in a general
     partner) of such Investor, and (c) Indemnitee is entitled to
     indemnification under this Agreement, then such Investor shall be entitled
     to indemnification hereunder to the same extent as the Indemnitee.

                                      11
<PAGE>

               IN WITNESS WHEREOF, the parties hereto have executed this
     Agreement on and as of the day and year first above written.

                              CHORUM TECHNOLOGIES INC.

                              By: _________________________________________

                              INDEMNITEE:

                              By: _________________________________________
                              Print Name:
                              Title:

                              Address: ____________________________________
                                       ____________________________________
                                       ____________________________________

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