NOTE AND WARRANT PURCHASE AGREEMENT


         This First  Amendment  to Note and  Warrant  Purchase  Agreement  (this
"First  Amendment") is dated as of April 13,  1995, and entered into by and
among DATA TRANSMISSION NETWORK CORPORATION, a Delaware corporation ("Company"),
and THE  NOTEHOLDERS  LISTED ON THE  SIGNATURE  PAGES HEREOF  (collectively  the
"Noteholders").

                                    RECITALS:

         WHEREAS,  Company and the initial  purchaser of the Notes  entered into
that certain Note and Warrant Purchase  Agreement dated as of June 30, 1994 (the
"Purchase  Agreement"),  the terms defined  therein being used herein as therein
defined; and

         WHEREAS, Company and Noteholders desire to amend the Purchase Agreement
as  hereinafter  set  forth to  modify  certain  financial  covenants  contained
therein;

         NOW,  THEREFORE,  subject to the terms and conditions herein contained,
the parties hereto hereby agree as follows:

         Section 1.  AMENDMENTS TO THE PURCHASE AGREEMENT.

         1.1      Subsection 10.5 of the Purchase Agreement hereby is
amended and restated in its entirety to read as follows:

                  "10.5.  Interest Coverage Ratio.  The Company will
         not permit the Interest Coverage Ratio to be less than
         2.0 to 1.0."

         1.2 Section 14 of the Purchase Agreement hereby is amended by adding in
its proper alphabetical order the following definition:

                  "Interest Coverage Ratio: For any calendar quarter,  the ratio
         of (i)  Consolidated  Operating Cash Flow for such calendar  quarter to
         (ii) consolidated interest expense for the Company and its Subsidiaries
         for such  calendar  quarter  determined in  accordance  with  generally
         accepted  accounting  principles;   provided,  however,  such  interest
         expense shall not include  amortization of deferred  offering costs nor
         any fees the  Company  is  obligated  to pay upon the  occurrence  of a
         "Trigger Event" as defined in Section 2.4 of the Bank Loan Agreement."

         1.3      Section 14 of the Purchase Agreement hereby is amended
by deleting in its entirety the definition of Consolidated
Tangible Net Worth.

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         Section 2.  COMPANY'S REPRESENTATIONS AND WARRANTIES.

         In order to induce the  Noteholders to enter into this First  Amendment
and to amend the  Purchase  Agreement  in the manner  provided  herein,  Company
represents  and warrants to the  Noteholders  that the following  statements are
true, correct and complete:

         2.1 Organization and Powers.  Company has all requisite corporate power
and  authority  to  enter  into  this  First  Amendment  and to  carry  out  the
transactions  contemplated  by, and perform its obligations  under, the Purchase
Agreement as amended by this First Amendment (the "Amended Agreement").

         2.2      Authorization of Agreements.  The execution and
delivery of this First Amendment have been duly authorized by all
necessary corporate action by Company.

         2.3 Binding Obligation.  This First Amendment and the Amended Agreement
are the legally valid and binding  obligations  of Company  enforceable  against
Company in accordance with their respective terms,  except as enforcement may be
limited to bankruptcy,  insolvency,  reorganization,  moratorium or similar laws
relating to or limiting  creditors' rights generally or by equitable  principles
relating to enforceability.

         Section 3.  NOTEHOLDERS' REPRESENTATIONS AND WARRANTIES.

         In order to induce  Company to enter into this First  Amendment  and to
amend the Purchase  Agreement in the manner  provided  herein,  the  Noteholders
represent  and warrant to Company  that  collectively  the  Noteholders  are the
holders of more than 50% in  principal  amount of the Notes  outstanding  on the
date of this First Amendment.

         Section 4.  MISCELLANEOUS.

         4.1 Reference to and Effect on the Purchase  Agreement.  From and after
the date of this First  Amendment,  each reference in the Purchase  Agreement to
"this Agreement",  "hereunder",  "hereof", "herein" or words of like import, and
each reference in any other documents relating to the Purchase Agreement,  shall
mean and be a  reference  to the  Purchase  Agreement  as  amended by this First
Amendment.  Except as specifically amended by this First Amendment, the Purchase
Agreement  and the other  documents  relating to the  Purchase  Agreement  shall
remain in full force and effect and are hereby ratified and confirmed.

         4.2 Execution in Counterparts;  Effectiveness. This First Amendment may
be executed in any number of counterparts and by the different parties herein in
separate  counterparts,  each of which when so executed and  delivered  shall be
deemed to be an original and all of which taken  together  shall  constitute but
one and the

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same instrument.  This First Amendment shall become effective upon the execution
of a counterpart hereof by each of the parties hereto.

         4.3      Governing Law.  This First Amendment shall be governed
by, and shall be construed and enforced in accordance with, the
laws of the State of New York.

         4.4 Headings.  Section and subsections headings in this First Amendment
are included herein for convenience of reference only and shall not constitute a
part of this First  Amendment for any other purpose or be given any  substantive
effect.

         WITNESS the due  execution  hereof by the  respective  duly  authorized
officers of the undersigned as of the date first above written.

                           COMPANY:

                           DATA TRANSMISSION NETWORK
                           CORPORATION, a Delaware
                           corporation



                           By:      /s/  Greg T. Sloma
                                  ------------------------------
                           Title:   Executive Vice President and
                                    Chief Operating Officer
                                  ------------------------------


                           NOTEHOLDERS:

                           EQUITABLE CAPITAL PRIVATE INCOME
                           AND EQUITY PARTNERSHIP II, L.P.

                           By:     EQUITABLE CAPITAL MANAGEMENT
                                   CORPORATION, its General Partner

                           By:     /s/   U. Peter C. Gummeson
                                  -------------------------------
                           Title:  Investment Officer

RCF\64596.1


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