FIRST AMENDMENT TO 1998 REVOLVING CREDIT AGREEMENT


         THIS FIRST  AMENDMENT to 1998  REVOLVING  CREDIT  AGREEMENT (the "First
Amendment")  is  intended  to  amend  the  terms of the  1998  Revolving  Credit
Agreement  (the   "Agreement")   dated  as  of  December  7,  1998,  among  DATA
TRANSMISSION NETWORK  CORPORATION;  FIRST NATIONAL BANK OF OMAHA; FIRST NATIONAL
BANK,  WAHOO,  NEBRASKA;  THE  FIRST  NATIONAL  BANK OF  CHICAGO;  NORWEST  BANK
NEBRASKA,  N.A.;  DRESDNER  BANK,  AG,  NEW  YORK  AND  GRAND  CAYMAN  BRANCHES;
MERCANTILE BANK OF ST. LOUIS,  N.A.; U.S. BANK,  NATIONAL  ASSOCIATION;  BANK OF
MONTREAL; LASALLE NATIONAL BANK; NATIONAL BANK OF CANADA; FIRST NATIONAL BANK OF
OMAHA, as Agent; and DRESDNER BANK, AG, NEW YORK AND GRAND CAYMAN  BRANCHES,  as
Documentation  Agent.  All terms and conditions of the Agreement shall remain in
full force and effect except as expressly amended herein.  All capitalized terms
herein shall have the meanings prescribed in the Agreement.  The Agreement shall
be amended as follows:

         1.    Section  2.1 of the  Agreement  is  hereby  amended  to  read  as
               follows:


               2.1 Revolving Credit.  Until the earlier of June 30, 2001, or the
               date on which the loan  hereunder  is converted to a term loan in
               accordance  with  Section 2.4, the  Revolving  Lenders  severally
               agree to advance  funds for  general  corporate  purposes  not to
               exceed $122,900,000 (the "Base Revolving Credit Facility") to the
               Borrower on a revolving credit basis (amounts  outstanding  under
               the Acquisition Notes,  Existing Term Notes and Related Bank Debt
               shall not be counted against such Base Revolving  Credit Facility
               limit).  Such  Advances  shall be made on a pro rata basis by the
               Revolving Lenders,  based on the following maximum advance limits
               and applicable  percentages for each Revolving Lender:  (i) as to
               FNB-O,  $19,000,000 (15.46%);  (ii) as to FNB-W, $490,000 (.40%);
               (iii) as to  First  of  Chicago,  $7,010,000  (5.7%);  (iv) as to
               Norwest,  $9,810,000  (7.98%);  (v)  as to  LaSalle,  $10,860,000
               (8.84%); (vi) as to Dresdner,  $23,164,000 (18.85%);  (vii) as to
               Mercantile,   $17,000,000  (13.83%),  (viii)  as  to  U.S.  Bank,
               $12,856,000  (10.46%);  (ix) as to Montreal,  $9,910,000 (8.06%);
               and (x) as to NBC, $12,800,000  (10.42%).  The Borrower shall not
               be entitled to any Advance hereunder if, after the making of such
               Advance,   the  Leverage  Ratio  would  exceed  thirty-six  (36),
               determined at the time of the Advance.  Nor shall the Borrower be
               entitled to any further  Advances  hereunder after the occurrence
               of a material  adverse  change in its  management  personnel,  as
               described  in Section  4.14(b),  or after the  occurrence  of any
               Event of Default with respect to the Borrower.  Advances shall be
               made,  on the terms and  conditions of this  Agreement,  upon the
               Borrower's  request.  Requests  shall be made by 12:00 noon Omaha
               time on the  Business  Day  prior  to the  requested  date of the

                                       1
                                    - 606 -
<PAGE>

               Advance.  Requests  shall be made by  presentation  to FNB-O of a
               drawing  certificate  in the form of  Exhibit  B. The  Borrower's
               obligation  to make  payments of  principal  and  interest on the
               foregoing   revolving  credit   indebtedness   shall  be  further
               evidenced by the Revolving Credit Notes.

         2.    The agent fee  referenced  in the last sentence of Section 2.2 of
               the Agreement is hereby increased from $40,000.00 to $50,000.00.

         3.    Section  3.13  of the  Agreement  is  hereby  amended  to read as
               follows:

               3.13 Financial Condition. The financial condition of the Borrower
               and its  Subsidiaries  is truly and  accurately  set forth in the
               most recent  financial  statements  which have been provided from
               time to time to the Lenders and no material adverse change in the
               financial  condition of the Borrower and its Subsidiaries,  taken
               as a  whole,  has  occurred  since  the  date of  such  financial
               statements.

         4.    All  references  in the  Agreement  to June  30,  2000,  shall be
               amended to June 30, 2001; and the reference in Section 2.4 to the
               maturity date of the  Converted  Notes shall be amended from June
               30, 2004 to June 30, 2005.

         5.    In  connection  with this First  Amendment,  each of the  Lenders
               whose pro rata portion of the Base Revolving  Credit  Facility is
               being  increased  will  receive  at  the  closing   specified  in
               Paragraph  6 below the  closing  fee  shown in  Exhibit B to this
               First Amendment.

         6.    On the closing  date for this First  Amendment,  which shall be a
               date  mutually  acceptable  to the  Borrower  and the Agent,  the
               Revolving Lenders shall either lend, or be repaid,  the principal
               amounts shown on Exhibit C hereof,  so that the principal amounts
               outstanding on the Base Revolving  Credit Facility will match the
               percentages shown for each Revolving Lender in Section 2.1 of the
               Agreement  as amended by this First  Amendment.  Effective  as of
               such closing date, the Borrower shall issue new Notes in the form
               specified  in  Exhibit A hereto to the  Revolving  Lenders in the
               respective  principal  amounts shown in Paragraph 1 of this First
               Amendment.  Upon the  delivery  of the new  Notes,  the  existing
               Revolving  Credit  Lenders  will  cancel  and will  return to the
               Borrower the existing Revolving Credit Notes.

         7.    This  First   Amendment   shall  not  affect  and  there   remain
               outstanding  from the Borrower to the Banks,  the  Existing  Term
               Notes and the Related Bank Debt.

         8.    This First Amendment may be executed in several  counterparts and
               such  counterparts  together  shall  constitute  one and the same
               instrument.

         Except as expressly  agreed  herein,  all terms of the Agreement  shall
remain in full force and effect.

                                       2
                                    - 607 -
<PAGE>

         IN WITNESS WHEREOF,  the undersigned have executed this FIRST AMENDMENT
TO 1998 REVOLVING CREDIT AGREEMENT dated as of January 29, 1999.


                                   DATA TRANSMISSION NETWORK
                                   CORPORATION



                                   By /s/ Brian Larson
                                    Title:CFO



                                   FIRST NATIONAL BANK OF OMAHA



                                   By James P. Bonham
                                    Title:Vice President





NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                    INITIALED:


                                    Borrower



                                       3
                                    - 608 -
<PAGE>



                              DRESDNER  BANK  AG,  NEW  YORK  AND
                              GRAND CAYMAN BRANCHES


                              By /s/ Patrick A. Keleher
                               Title:Vice President


                              By /s/ Brian Haughney
                               Title:Assistant Treasurer







NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                              INITIALED:


                              Borrower


                                       4
                                    - 609 -
<PAGE>









                              FIRST NATIONAL BANK, WAHOO,
                              NEBRASKA



                              By /s/ Elizabeth Rezac
                               Title:Second Vice President








NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                              INITIALED:


                              Borrower



                                       5
                                    - 610 -
<PAGE>





                              THE FIRST NATIONAL BANK OF CHICAGO


                              By /s/ Nathan L. Bloch
                               Title:First Vice President










NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                              INITIALED:


                              Borrower



                                       6
                                    - 611 -
<PAGE>





                              NORWEST BANK NEBRASKA, N.A.




                              By /s/James 
                               Title:Vice President












NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                              INITIALED:


                              Borrower



                                       7
                                    - 612 -
<PAGE>





                              LASALLE NATIONAL BANK, a national
                              banking association




                              By/s/ Tom Harmon
                               Title:Assistant Vice President






NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                              INITIALED:


                              Borrower



                                       8
                                    - 613 -
<PAGE>






                              MERCANTILE BANK OF
                              ST. LOUIS, N.A.


                              By /s/Joseph L. Sooter, Jr.
                               Title:Vice President






NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                   INITIALED:


                                   Borrower




                                       9
                                    - 614 -
<PAGE>

                                    U.S. BANK, NATIONAL
                                    ASSOCIATION


                                    By/s/ Beth Morgan
                                     Title:Vice President










NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                   INITIALED:


                                   Borrower




                                       10
                                    - 615 -
<PAGE>




                                    NATIONAL BANK OF CANADA, a Canadian bank



                                    By /s/
                                     Title:Vice President





NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                   INITIALED:


                                    Borrower




                                       11
                                    - 616 -
<PAGE>




                                    BANK OF MONTREAL, a Canadian bank





                                    By/s/ Karen Klapper
                                     Title:Director








NOTICE: A credit  agreement must be in writing to be enforceable  under Nebraska
law. To protect you and us from any  misunderstandings  or disappointments,  any
contract,  promise,  undertaking,  or offer to forebear repayment of money or to
make any other financial  accommodation in connection with this loan of money or
grant or extension of credit,  or any amendment of,  cancellation of, waiver of,
or  substitution  for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                   INITIALED:


                                    Borrower



                                       12
                                    - 617 -
<PAGE>



                                    EXHIBIT A



              TO FIRST AMENDMENT TO 1998 REVOLVING CREDIT AGREEMENT
                                      among
                           DATA TRANSMISSION NETWORK,
                          FIRST NATIONAL BANK OF OMAHA,
                      FIRST NATIONAL BANK, WAHOO, NEBRASKA,
                       THE FIRST NATIONAL BANK OF CHICAGO,
                          NORWEST BANK NEBRASKA, N.A.,
              DRESDNER BANK AG, NEW YORK AND GRAND CAYMAN BRANCHES,
                       MERCANTILE BANK OF ST. LOUIS, N.A.,
                        U.S. BANK, NATIONAL ASSOCIATION,
                                BANK OF MONTREAL,
                 LASALLE NATIONAL BANK, NATIONAL BANK OF CANADA,
                     FIRST NATIONAL BANK OF OMAHA, as Agent
                                       AND
                         DRESDNER BANK AG, NEW YORK AND
                  GRAND CAYMAN BRANCHES, as Documentation Agent




                                  FORM OF NOTES



                                       13
                                    - 618 -
<PAGE>

                        SECURED BUSINESS PROMISSORY NOTE


Omaha, Nebraska                                   $
                      , 19                                        June 30, 2001
---------------    ----                                           -------------
(Note Date)                                                      (Maturity Date)


                              REVOLVING NOTE TERMS

         On or before  June 30,  2001,  DATA  TRANSMISSION  NETWORK  CORPORATION
("Maker")  promises to pay to the order of  [REVOLVING  LENDER]  ("Lender")  the
principal sum hereof, which shall be the lesser  of_____________________________
Dollars, or so much thereof as may have been advanced by Lender, either directly
under this Note or as an advance pursuant to the 1998 Revolving Credit Agreement
dated as of December  7, 1998,  as amended  from time to time (the  "Agreement")
among Maker and Lender,  First  National  Bank of Omaha,  First  National  Bank,
Wahoo,  Nebraska,  The First  National Bank of Chicago,  Norwest Bank  Nebraska,
N.A.,  LaSalle  National  Bank,  Dresdner  Bank AG,  New York and  Grand  Cayman
Branches,  Mercantile  Bank of St. Louis,  N.A.,  Bank of Montreal,  U.S.  Bank,
National Association, and National Bank of Canada (collectively, the "Lenders"),
First  National Bank of Omaha,  as Agent,  and Dresdner  Bank,  AG, New York and
Grand Cayman Branches, as Documentation Agent. All capitalized terms not defined
herein shall have their respective meanings as set forth in the Agreement.

         Interest  shall accrue on the  principal  sum hereof from and including
the  Note  Date  above  to the  earlier  of the  Maturity  Date  or the  date of
Conversion (as such term is defined  hereafter) at a variable rate,  which shall
fluctuate on a monthly  basis,  equal to the rate announced from time to time by
FNB-O as its "National Base Rate" minus a margin as determined below. The margin
shall be  adjusted  quarterly  after  receipt  of Maker's  Quarterly  Compliance
Certificate (as defined in the Agreement).  Adjustments  shall be retroactive to
the beginning of the current quarter.

               (a) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior  quarter,  the Leverage Ratio was greater than 42, the
         margin  for the  current  quarter  (meaning  the  quarter  in which the
         certificate is required to be delivered) shall be .25%.

               (b) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior  quarter,  the Leverage  Ratio was greater than 36 but
         equal to or less than 42, the margin for the current  quarter  shall be
         .50%.

                                       14
                                    - 619 -
<PAGE>

               (c) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior  quarter,  the Leverage  Ratio was greater than 30 but
         equal to or less than 36, the margin for the current  quarter  shall be
         .75%.

               (d) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior  quarter,  the Leverage  Ratio was greater than 24 but
         equal to or less than 30, the margin for the current  quarter  shall be
         1.00%.

               (e) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior  quarter,  the Leverage  Ratio was greater than 18 but
         equal to or less than 24, the margin for the current  quarter  shall be
         1.25%.

               (f) If the Quarterly Compliance Certificate shows that, as of the
         end of the prior quarter,  the Leverage Ratio was equal to or less than
         18, the margin for the current quarter shall be 1.375%.

The Base Rate minus the  applicable  margin as determined  above is  hereinafter
referred to as the  "Revolving  Credit Rate."  Changes in the Base Rate shall be
effective on the first day of each month, based on the Base Rate in effect as of
such day.  Interest  shall be due upon the  rendering  of each  monthly  invoice
therefor by FNB-O.


                                 TERM NOTE TERMS

         Upon the earlier of: (i) June 30, 2001;  or (ii) Maker's  giving notice
of its election to convert the revolving  credit loan evidenced by this Note, or
any portion  thereof,  to a term loan, the revolving loan  referenced  above (or
applicable  portion  thereof)  shall be  deemed  converted  to a term  loan (the
"Conversion").  Any such term loan shall be evidenced  by notes (the  "Converted
Notes") separate from the initial  Revolving Credit Notes.  Upon the issuance of
Converted Notes, the Revolving Credit Facility shall be reduced by the principal
amount of such Converted  Notes (and shall be increased to the extent  permitted
in Section 2.1(b) of the Agreement) and no further Advances shall be made by the
Revolving  Lenders  on the  converted  amount.  The then  outstanding  principal
hereunder  shall become due and payable in  forty-eight  equal  installments  of
principal,  with the  first  such  installment  due on the last day of the month
following  Conversion,  or,  if such  day is not a  Business  Day,  on the  next
succeeding  Business Day,  subsequent  installments  due on the last day of each
consecutive  month  thereafter.  In any  event,  the total  amount of all unpaid
principal and accrued interest  hereunder shall be due and payable no later than
June 30, 2005.

         After  Conversion,  interest shall accrue on the principal  outstanding
from time to time at a variable rate,  which shall fluctuate on a monthly basis,
which is equal to the Revolving Credit Rate plus .25%. For purposes of computing
such variable rate, changes in the Base Rate shall be effective on the first day
of each  month  based on the Base Rate in  effect  on such day.  Notwithstanding
anything in the foregoing to the contrary, after Conversion,  Maker may elect to

                                       15
                                    - 620 -
<PAGE>

have a fixed  interest  rate  apply to the  outstanding  Principal  Loan  Amount
converted  and  outstanding  after the date of giving  notice of such fixed rate
election  (the  "Fixed  Rate  Notice").  Such  fixed  rate shall be equal to the
greater of:
               (a) the  Revolving  Credit  Rate  in  effect  on the  date of the
         notice1, plus .375%, or

               (b) the average of the yields on constant maturity Treasury Bonds
         with  maturities  of three  years  and five  years,  as  quoted  in the
         immediately  preceding monthly Federal Reserve Statistical Release (the
         "Release") plus the following  incremental  percentage determined based
         upon the Leverage Ratio2 as of the last day of the preceding month: (x)
         if the Leverage  Ratio is greater than 36, the  incremental  percentage
         shall be 2.25%; (y) if the Leverage Ratio is greater than 24 but not in
         excess of 36, the incremental percentage shall be 2.00%; and (z) if the
         Leverage  Ratio is 24 or less,  the  incremental  percentage  should be
         1.75%;

Any election of a fixed rate by Maker shall be final and  irrevocable.  Interest
shall  be due  each  month  concurrently  with the  Maker's  principal  payment.
Notwithstanding  anything to the contrary  elsewhere  herein,  after an Event of
Default has occurred interest shall accrue on the entire outstanding  balance of
principal and interest at a fluctuating rate equal to the Default Rate. Interest
shall be calculated on the basis of the actual number of days  outstanding and a
360-day  year.  Interest  shall  continue to accrue on the full  unpaid  balance
hereunder  notwithstanding any permitted or unpermitted failure of Maker to make
a  scheduled  payment or the fact that a  scheduled  payment  day falls on a day
other  than  a  Business  Day.  If  Maker's  most  recent  Quarterly  Compliance
Certificate  shows that, as of the end of the prior quarter,  the Leverage Ratio
was in excess of thirty-six (36) at the end of such quarter, the current quarter
shall be deemed a "Restricted Quarter." If, any time during a Restricted Quarter
(including,  without  limitation,  during  any period in such  quarter  prior to
delivery of the Quarterly Compliance Certificate), the interest rate accruing on
any Existing Term Note (as defined in the  Agreement) or Converted  Note is less
than 7.50% per annum, a "Trigger  Event" shall be deemed to have occurred.  Upon
the occurrence of a Trigger Event, Maker shall be obligated to pay the following
fees: (i) .375% of the  outstanding  principal  balance as of the date preceding
the Trigger  Event of each  Existing  Term Note or Converted  Note which accrues
interest at less than seven and one-half  percent (7.50%) per annum which amount

                                       16
                                    - 621 -
<PAGE>

shall be payable  promptly  upon  invoicing  by FNB-O;  (ii) the same  amount as
computed  in clause (i),  payable on the  six-month  anniversary  of the Trigger
Event;  and (iii) the same  amount as  computed  in clause  (i),  payable on the
twelve-month anniversary of the Trigger Event.

         Maker  may at any time  prepay in whole or in part the  Principal  Loan
Amount  outstanding  under this Revolving Credit Note or a Converted Note if the
Maker has given the  Revolving  Lenders  at least two (2)  business  days  prior
written notice of its intention to make such prepayment. Any such prepayment may
be made  without  penalty  except for a Converted  Note as to which  interest is
accrued at a fixed rate in  accordance  with  clause (a) or (b) above,  in which
event a  prepayment  penalty  shall be due to the Lender,  at  Lender's  option,
either: (1) the Make-Whole Premium due in respect of such prepayment; or (2) the
applicable  prepayment fee as set forth below. The applicable prepayment fee for
any Converted Note shall be: (i) if the notice electing fixed interest was given
within twelve (12) months of Conversion, the fee shall be 1.50% of the amount of
such  prepayment;  (ii) if the notice  electing  fixed  interest was given after
twelve  (12)  months  of  Conversion,  but  within  twenty-four  (24)  months of
Conversion, the fee shall be .75% of the amount of such prepayment; and (iii) if
the notice  electing  fixed interest was given after twenty- four (24) months of
Conversion,  but within  thirty-six (36) months of Conversion,  the fee shall be
 .30% of the amount of such prepayment.


                                  GENERAL TERMS

         Payment of this Note and the performance of Maker's  obligations  under
the  Agreement  ("Obligations")  are secured by a security  interest  granted to
First  National  Bank of Omaha,  as agent for the Lenders and others  ("Agent"),
under the Security Agreement in:

         All of Maker's accounts, accounts receivable, chattel paper, documents,
         instruments, goods, inventory, equipment, general intangibles, contract
         rights,  all rights of Maker in deposits and advance  payments  made to
         Maker by its customers and  Subscribers,  accounts due from advertisers
         and all  ownership,  proprietary,  copyright,  trade  secret  and other
         intellectual   property  rights  in  and  to  computer   software  (and
         specifically  including,  without  limitation,  all such  rights in DTN
         transmission  computer  software used in the provision of the Basic DTN
         Subscription Service and Farm Dayta Service to Maker's Subscribers) and
         all  documentation,  source code,  information  and works of authorship
         pertaining  thereto,  all  now  owned  or  hereafter  acquired  and all
         proceeds and products thereof; and


such  additional  collateral as is more  specifically  described in the Security
Agreement.

         Maker's liability under its Obligations shall not be affected by any of
the following:

                                       17
                                    - 622 -
<PAGE>

              Acceptance  or retention  by Lender or Agent of other  property or
         interests as security for the Obligations,  or for the liability of any
         person other than a Maker with respect to the Obligations;

              The release of all or any of the  Collateral or other security for
         any of the Obligations to any Maker;
                  
              Any release, extension, renewal, modification or compromise of any
         of the Obligations or the liability of any obligor thereon; or

              Failure  by Lender or Agent to  resort  to other  security  or any
         person  liable  for  any of the  Obligations  before  resorting  to the
         Collateral.

         Neither  Lender nor Agent is required to take any action  whatsoever in
respect of the Collateral. Impairment or destruction of the Collateral shall not
release Maker of its liability hereunder.

         Maker represents, warrants and covenants as follows:

              Maker is authorized  to grant to Agent a security  interest in the
         Collateral;

              This Note, the Agreement and the Security Agreement have been duly
         authorized,  executed and delivered by the Maker and constitute  legal,
         valid and binding obligations of Maker;

              This Note evidences a loan for business or agricultural  purposes;
         and

              Maker agrees to pay all costs of  collection  in  connection  with
         this  Note,  the  Agreement  and  the  Security  Agreement,   including
         reasonable attorneys' fees and legal expenses.

         Upon the failure of Maker to make any payment of  principal or interest
when  due  hereunder  or the  occurrence  of any  Event of  Default,  all of the
Obligations  shall, at the option of Agent and without notice or demand,  mature
and become  immediately  due and  payable;  and Agent  shall have all rights and
remedies  for  default  provided  by the  Uniform  Commercial  Code,  any  other
applicable law and/or the Obligations.


         All costs and  expenses  incurred by Lender or Agent in  enforcing  its
rights under this Note or any mortgage,  endorsement, surety agreement, guaranty
relating  thereto  are the  obligation  of  Maker  and are  immediately  due and
payable.  Interest  shall  accrue on such  costs and  expenses  from the date of
incurrence at the rate  specified  herein for  delinquent  Note  payments.  Each
Maker,  endorser,  surety and  guarantor  hereby  waives  presentment,  protest,
demand, notice of dishonor, and the defense of any statute of limitations.

                                       18
                                    - 623 -
<PAGE>

         Without  affecting  the  liability  of any Maker,  endorser,  surety or
guarantor, the holder or Agent may, without notice, renew or extend the time for
payment,  accept  partial  payments,  release or impair any  Collateral or other
security for the payment of this Note or agree to sue any party liable on it.

         Neither  Lender  nor Agent  shall be deemed to have  waived  any of its
rights  upon or under  this Note,  or under any  mortgage,  endorsement,  surety
agreement or guaranty, unless such waivers be in writing and signed by Lender or
Agent,  as the case may be. No delay or  omission on the part of Lender or Agent
in  exercising  any right  shall  operate as a waiver of such right or any other
right. A waiver on any one occasion shall not be construed as a bar to or waiver
of any right on any future occasion.  All rights and remedies of Lender or Agent
on  liabilities  or the  Collateral,  whether  evidenced  hereby or by any other
instrument  or papers,  shall be cumulative  and may be exercised  singularly or
concurrently.

         Maker,  if more  than  one,  shall  be  jointly  and  severally  liable
hereunder and all  provisions  hereof  regarding the  liabilities or security of
Maker shall apply to any  liability or any security of any or all of them.  This
Note shall be  binding  upon the heirs,  executors,  administrators,  assigns or
successors of Maker;  shall constitute a continuing  agreement,  applying to all
future  as  well  as  existing  transactions,  whether  or not of the  character
contemplated  at the date of this Note, and if all  transactions  between Lender
and Maker shall be at any time closed,  shall be equally  applicable  to any new
transactions thereafter, provided that Lender's interest in the Collateral shall
be limited to the extent  provided  in the  Security  Agreement;  shall  benefit
Lender,   its   successors   and  assigns;   and  shall  so  continue  in  force
notwithstanding any change in any partnership party hereto,  whether such change
occurs through death, retirement or otherwise.

         All  obligations  of Maker  hereunder  shall be payable in  immediately
available funds in lawful money of the United States of America at the principal
office of First  National  Bank of Omaha in  Omaha,  Nebraska  or at such  other
address as may be designated by Bank in writing.

         This  Note  shall be  construed  according  to the laws of the State of
Nebraska.

         Unless the content otherwise requires,  all terms used herein which are
defined in the Uniform Commercial Code shall have the meanings therein stated.

         Any provision of this Note which is prohibited or  unenforceable in any
jurisdiction  shall,  as to such  jurisdiction,  be ineffective to the extent of
such  prohibition  or  unenforceability   without   invalidating  the  remaining
provisions  hereof or affecting the validity or enforceability of such provision
in any other jurisdiction.

         This Note is given in  substitution  of that certain  Secured  Business
Promissory  Note dated  _____________,  ____ the  original  principal  amount of
$____________.  This Note shall not affect,  and there remains  outstanding from
the Maker to certain of the Lenders the Related Bank Debt and the Existing  Term
Notes  (as such  terms are  defined  in the  Agreement),  and,  as to each,  all
extensions, renewals, and substitutions of or for the foregoing.

                                       19
                                    - 624 -
<PAGE>

         Executed as of this _____ day of _____________, _____.


                                            DATA TRANSMISSION NETWORK
                                               CORPORATION


                                             By:
                                          Title:

                                       20
                                    - 625 -
<PAGE>

                            PROMISSORY NOTE SCHEDULE

                     Loan Advances and Payments of Principal

                      DATA TRANSMISSION NETWORK CORPORATION




REVOLVING NOTE ADVANCES AND PAYMENTS:


                           Amount of                         Unpaid
           Amount        Principal Paid      Amount of      Principal   Notation
Date     of Advance        or Prepaid      Interest Paid     Balance    Made By
----     ----------     ---------------    -------------    ---------   --------

                                       21
                                    - 626 -
<PAGE>



TERM NOTE:

Date of Conversion:

Amount Due at Date of Conversion:



    Fixed Rate Notice Date:                    Fixed Rate:           %


                           Amount of                         Unpaid
           Amount        Principal Paid      Amount of      Principal   Notation
Date     of Advance        or Prepaid      Interest Paid     Balance    Made By
----     ----------      --------------    -------------    ---------   --------






                                       22
                                    - 627 -
<PAGE>



                                    EXHIBIT C



              TO FIRST AMENDMENT TO 1998 REVOLVING CREDIT AGREEMENT
                                      among
                           DATA TRANSMISSION NETWORK,
                          FIRST NATIONAL BANK OF OMAHA,
                      FIRST NATIONAL BANK, WAHOO, NEBRASKA,
                       THE FIRST NATIONAL BANK OF CHICAGO,
                          NORWEST BANK NEBRASKA, N.A.,
              DRESDNER BANK AG, NEW YORK AND GRAND CAYMAN BRANCHES,
                       MERCANTILE BANK OF ST. LOUIS, N.A.,
                        U.S. BANK, NATIONAL ASSOCIATION,
                                BANK OF MONTREAL,
                 LASALLE NATIONAL BANK, NATIONAL BANK OF CANADA,
                     FIRST NATIONAL BANK OF OMAHA, as Agent
                                       AND
                         DRESDNER BANK AG, NEW YORK AND
                  GRAND CAYMAN BRANCHES, as Documentation Agent





                               CLOSING ALLOCATIONS








                                       23
                                    - 628 -
<PAGE>



                                    EXHIBIT C
                                       TO
               FIRST AMENDMENT TO 1998 REVOLVING CREDIT AGREEMENT

<TABLE>
<CAPTION>

Lender       Current       Current         Revised       Revised      Adjustment
                 %       Outstanding %                 Outstanding


<S>           <C>         <C>              <C>         <C>          <C>         
FNB-O         19.80       $10,989,000      15.46%      $ 8,580,300  $(2,408,700)

FNB-W           .40           222,000        .40%          222,000     No Change

First of 
   Chicago     2.49         1,381,950       5.70%        3,163,500    1,781,550

Norwest        8.04         4,462,200       7.98%        4,428,900    (  33,300)

LaSalle       10.30         5,716,500       8.84%        4,906,200    ( 810,300)

Dresdner      10.54         5,849,700      18.85%       10,461,750    4,612,050

Mercantile    13.92         7,725,600      13.83%        7,675,650    (  49,950)

Montreal       8.13         4,512,150       8.06%        4,473,300    (  38,850)

U.S. Bank     10.54         5,849,700      10.46%        5,805,300    (  44,400)

NBC           15.84         8,791,200      10.42%        5,783,100   (3,008,100)

TOTALS       100.00%      $55,500,000     100.00%      $55,500,000        $  -0-




</TABLE>

                                       24
                                    - 629 -
<PAGE>

                                    EXHIBIT B

                       TO 1998 REVOLVING CREDIT AGREEMENT
                                      among
                           DATA TRANSMISSION NETWORK,
                          FIRST NATIONAL BANK OF OMAHA,
                      FIRST NATIONAL BANK, WAHOO, NEBRASKA,
                       THE FIRST NATIONAL BANK OF CHICAGO,
                          NORWEST BANK NEBRASKA, N.A.,
              DRESDNER BANK AG, NEW YORK AND GRAND CAYMAN BRANCHES,
                       MERCANTILE BANK OF ST. LOUIS, N.A.,
                        U.S. BANK, NATIONAL ASSOCIATION,
                                BANK OF MONTREAL,
                             LASALLE NATIONAL BANK,
                            NATIONAL BANK OF CANADA,
                     FIRST NATIONAL BANK OF OMAHA, as Agent
                                       AND
                         DRESDNER BANK AG, NEW YORK AND
                  GRAND CAYMAN BRANCHES, as Documentation Agent




                                  CLOSING FEES





                                       25
                                    - 630 -
<PAGE>

<TABLE>
<CAPTION>

                                    EXHIBIT B
                                       TO
               FIRST AMENDMENT TO 1998 REVOLVING CREDIT AGREEMENT


BANKS RECEIVING .25% OF INCREASE:
      Bank                       Amount of Increase                 Closing Fee

      <S>                         <C>                               <C>       
      FNB-O                       $  3,000,000                      $ 7,500.00
      LaSalle                     $  2,540,000                      $ 6,350.00






BANKS RECEIVING .375% OF INCREASE:
         Bank                       Amount of Increase             Closing Fee

      FNB-W                       $   165,000                       $   618.75
      First of Chicago            $ 4,995,000                       $18,731.25
      Norwest                     $ 3,310,000                       $12,412.50
      Dresdner                    $14,649,000                       $54,933.75
      Mercantile                  $ 5,755,000                       $21,581.25
      U.S. Bank                   $ 4,341,000                       $16,278.75
      Montreal                    $ 3,345,000                       $12,543.75



BANKS RECEIVING .00% OF INCREASE
         Bank                       Amount of Increase             Closing Fee
         NBC                        $    -0-                          $ -0-





                                       26
                                    - 631 -
<FN>

--------
         1  Determined  based on the  Leverage  Ratio  calculated  on the  Total
         Indebtedness  and  Operating  Cash  Flow  as of  the  last  day  of the
         preceding  month,  adjusted to show any increases in the Leverage Ratio
         as a result of additional Total  Indebtedness  incurred (reduced by any
         principal  payments on such Total  Indebtedness)  during the quarter in
         which the rate is being fixed as described above.


</FN>

</TABLE>