1998 SECURITY AGREEMENT

         THIS 1998 SECURITY  AGREEMENT  (this  "Security  Agreement") is entered
into as of December 7, 1998, between DATA TRANSMISSION  NETWORK  CORPORATION,  a
Delaware  corporation  having its principal place of business at Suite 200, 9110
West Dodge Road,  Omaha,  Nebraska 68114 (the "Debtor"),  FIRST NATIONAL BANK OF
OMAHA, a national banking  association having its principal place of business at
One First National Center,  Omaha, Nebraska 68102 as agent ("Secured Party") for
itself and FIRST NATIONAL BANK, WAHOO,  NEBRASKA, a national banking association
having its principal place of business at Wahoo,  Nebraska 68066 ("FNB-W"),  THE
FIRST  NATIONAL  BANK OF  CHICAGO,  a national  banking  association  having its
principal  place of  business at One First  National  Plaza,  Chicago,  Illinois
60670-0173 (First of Chicago),  NORWEST BANK NEBRASKA,  N.A., a national banking
association  having its principal  place of business at 20th and Farnam Streets,
Omaha, Nebraska 68102 ("Norwest"),  U.S. BANK, NATIONAL ASSOCIATION,  a national
banking  association  having  its  principal  place  of  business  at 13th and M
Streets,  Lincoln,  Nebraska 68508 ("U.S. Bank"), DRESDNER BANK AG, NEW YORK AND
GRAND CAYMAN BRANCHES,  being  represented by its office at 75 Wall Street,  New
York, New York 10005 Dresdner,  MERCANTILE  BANK OF ST. LOUIS,  N.A., a national
banking  association  having its principal  place of business at One Mercantile,
7th and  Washington  Streets,  St. Louis,  Missouri  63101  Mercantile,  BANK OF
MONTREAL,  a Canadian bank being  represented  by its office at 430 Park Avenue,
New York, New York 10022  Montreal,  LASALLE  NATIONAL BANK, a national  banking
association  being  represented by its office at One  Metropolitan  Square,  211
North Broadway,  St. Louis, Missouri 63102 LaSalle, and NATIONAL BANK OF CANADA,
a Canadian bank being represented by its office at 1200 17th Street, Suite 2760,
Denver, Colorado 80202.

                                   WITNESSETH:

         WHEREAS,  Debtor  and  Secured  Party are  parties  to a 1997  Security
Agreement  dated as of February 26, 1997 as amended by a First Amendment to 1997
Security  Agreement  dated as of May 15, 1998, as so amended and  restated,  the
1997 Security Agreement;

         WHEREAS, Debtor and Secured Party wish to further amend and restate the
1997 Security Agreement;

         WHEREAS,  Debtor  and  Secured  Party  wish to have this 1998  Security
Agreement  be the  controlling  agreement  with respect to the matters set forth
herein, which shall supersede the 1997 Security Agreement; and

         WHEREAS,  the  Debtor  and  Secured  Party do not  intend for this 1998
Security  Agreement to be deemed to extinguish any existing  indebtedness of the
Debtor or to release, terminate or affect the priority of any security therefor;

         NOW,  THEREFORE,  in consideration of the premises,  and for other good
and  valuable  consideration,  the  receipt and  sufficiency  of which is hereby
acknowledged, it is agreed as follows:


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<PAGE>

         1. Grant of Security  Interest.  Debtor  hereby grants to Secured Party
and  reaffirms  its prior grant of a security  interest in the  Collateral.  All
capitalized  terms not  defined  in this  Security  Agreement  shall  have their
respective  meanings as set forth in the 1998  Revolving  Credit  Agreement,  as
described in Section 3(i) below.

         2. Collateral.  The Collateral to which this Security  Agreement refers
is described on Exhibit A.

         3. Obligations  Secured.  The security interest granted herein is given
to secure all  present  and  future  obligations  of Debtor:  (i) under the 1998
Revolving Credit Agreement dated as of December 7, 1998, as amended from time to
time between the Debtor and First National Bank of Omaha, FNB-W, Norwest,  First
of Chicago, U.S. Bank, Dresdner,  Mercantile,  Montreal,  LaSalle, and NBC; (ii)
under the 1997  Revolving  Credit  Agreement  dated as of February 26, 1997,  as
amended from time to time between the Debtor and First  National  Bank of Omaha,
and the other Lenders named therein; (iii) under the 1997 Term Credit Agreement,
dated as of February 26,  1997,  between the Debtor and First  National  Bank of
Omaha, and the other Lenders named therein,  which agreement  further amends and
restates  the 1996 Term  Credit  Agreement  dated as of May 3, 1996  among  such
parties;  (iv) under the 1996 Revolving  Credit  Agreement  dated as of June 28,
1996 as amended from time to time between the Borrower,  First  National Bank of
Omaha,  and the other  Lenders named  therein;  (v) under the 1995 Restated Loan
Agreement  dated as of June 29,  1995,  as amended from time to time between the
Borrower and First National Bank of Omaha,  and the other Lenders named therein;
(vi) under the 1993  Restated  Loan  Agreement  dated as of November 8, 1993, as
amended from time to time,  between Debtor and First National Bank of Omaha, and
other Lenders named therein;  (vii) under any interest rate protection agreement
entered into by Debtor with one or more Lenders;  (viii) under any and all Notes
previously,  now or hereafter  made by Debtor to the Lenders  pursuant to any of
the foregoing Loan  Agreements and interest rate  protection  agreements (all of
which are referred to herein as the "Loan  Agreements") or any predecessor  loan
agreements, including, without limitation, the Existing Term Notes and any notes
given in extension,  renewal or substitution of the Notes; (ix) to reimburse the
Secured Party for all sums, if any, advanced to protect the Collateral;  and (x)
to reimburse  Secured Party for all costs and expenses incurred in collection of
the foregoing, including, without limitation, costs of repossession and sale and
reasonable  attorneys'  fees.  This  Security  Agreement  shall not be deemed to
extinguish  existing  indebtedness  of the  Debtor  under any of the  agreements
referenced  in  this  Section  3 or any of the  notes  issued  thereunder  or to
release, terminate or affect the priority of any security therefor.

         4. Representations and Warranties. Debtor represents and warrants:

              (a)  Debt.  Debtor  is  justly  indebted  to the  Lenders  for the
         obligations  secured and has no set off or  counterclaim  with  respect
         thereto;

              (b)  Possession  and  Ownership.  The  Collateral is or will be in
         Debtor's  possession  (except for  equipment or  inventory  provided to
         Debtor's  customers in the ordinary  course of business) and Debtor has
         or will acquire  absolute  title thereto and will defend the Collateral
         against the claims and demands of all persons other than Secured Party.
         Debtor has full right and power to grant the security  interest  herein
         to Secured Party.

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              (c) Liens and Encumbrances.  No financing  statement  covering the
         Collateral or other filing  evidencing  any lien or  encumbrance on the
         Collateral  is on file in any  public  office  and  there  is no  lien,
         security  interest  or  encumbrance  on the  Collateral  except for the
         security  interest  held by Secured  Party  pursuant  to this  Security
         Agreement and for those security interests  described on Schedule A and
         other filings in favor of Secured Party.

              (d)  Truth  of  Representations.   All  information,   statements,
         representations,  and  warranties  made  by  Debtor  herein  and in any
         financial or credit  statement,  application  for credit,  or any other
         writing executed prior to or substantially  contemporaneously  herewith
         are true, accurate and complete in all material respects.

              (e) Location.  Debtor has its chief  executive  office,  principal
         place of business  and place where it keeps it records  concerning  the
         Collateral at Suite 200, 9110 West Dodge Road,  Omaha,  Nebraska 68114.
         The Borrower also keeps certain of its records regarding the Collateral
         at 11275 Aurora Avenue, Des Moines, Iowa 50322.

              (f)  Authority.  Debtor  has full  authority  to enter  into  this
         Security   Agreement  and  in  so  doing  is  not  violating  any  law,
         regulation,  or agreement with third parties.  This Security  Agreement
         has been duly and validly authorized by all necessary corporate action.

         5. Covenants.  Debtor covenants and agrees:

              (a) Liens and Encumbrances.  Except as otherwise expressly allowed
         by the Loan Agreements, Debtor shall keep the Collateral free and clear
         of liens,  encumbrances,  security interests, and other claims of third
         parties and will, at Debtor's  expense,  defend the Collateral  against
         the claims and demands of all third parties.  Debtor shall promptly pay
         and discharge any indebtedness  owing to any third party who, by reason
         of said  indebtedness,  could  obtain or become  entitled  to a lien or
         encumbrance  on the  Collateral,  other  than such  indebtedness  being
         contested  in good faith and with  respect to which  adequate  reserves
         have been established.

              (b) Proceeds;  Sale. Debtor shall not sell or otherwise dispose of
         any Collateral  without first  obtaining the written consent of Secured
         Party;  provided,   however,  that  Debtor  may  provide  equipment  or
         inventory to customers and others in the ordinary course of business so
         long as: (i) such equipment or inventory is not sold to customers;  and
         (ii) the value of equipment or inventory  disposed of to others  (e.g.,
         for salvage purposes) does not exceed, in aggregate,  $500,000.  Debtor
         shall  at all  times  keep the  Collateral  and the  proceeds  from any
         authorized  or  unauthorized   disposition  thereof   identifiable  and
         separate  from  the  other  property  of  Debtor  or any  third  party;
         provided,  however,  that  Debtor  may  commingle  and use for  general
         corporate  purposes up to $500,000 in  aggregate  net book value of the
         proceeds  of sale or  other  disposition  of  obsolete  or  out-of-date
         equipment or inventory disposed of in accordance with clause (ii) above
         in this Section 5(b).

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              (c)  Protection  of Value.  Debtor  shall use the utmost  care and
         diligence to protect and preserve the Collateral,  and shall not commit
         nor  suffer  any waste to occur  with  respect  to the  Collateral.  In
         pursuance of the  foregoing,  Debtor shall  maintain the  Collateral in
         good condition and repair and shall take such steps as are necessary or
         as are  requested  by Secured  Party to prevent any  impairment  of the
         value of the Collateral.

              (d) Taxes.  Debtor shall  promptly pay and  discharge  any and all
         taxes,  levies and other impositions made upon the Collateral which may
         give rise to liens upon the  Collateral  if unpaid or which are imposed
         upon the creation,  perfection, or continuance of the security interest
         provided for herein, other than taxes being contested in good faith and
         with respect to which adequate reserves have been established.

              (e)  Insurance.  All risk of loss of, damage to, or destruction of
         the  Collateral  shall at all times be on Debtor.  Debtor shall procure
         and maintain,  at its own expense,  insurance  covering the  Collateral
         against all risks  under  policies  and with  companies  acceptable  to
         Secured Party, for the duration of this Security  Agreement (except for
         equipment  provided to Debtor's  customers  in the  ordinary  course of
         business). Such policies shall be written for and shall name Debtor and
         Secured Party as their  interests may appear,  shall contain a standard
         loss payable clause in favor of Secured Party. Proof of insurance shall
         be provided to Secured  Party upon  request.  For purposes of security,
         Debtor hereby  assigns to Secured Party any and all monies  (including,
         without  limitation,  proceeds  of  insurance  and  refunds of unearned
         premiums)  due or to become due under any such  policy.  Debtor  hereby
         directs the issuer of any such  policy to pay any such monies  directly
         to  Secured  Party.  Secured  Party may act as  attorney  for Debtor in
         obtaining,  settling and adjusting  such insurance and in endorsing any
         checks or drafts paid thereunder.

              (f) Secured  Party as Payee.  Debtor  shall take such steps as are
         necessary or as are  requested by Secured  Party to have Secured  Party
         named as a payee on any check,  draft or other  document or  instrument
         which  Debtor may obtain or  anticipate  obtaining  with respect to the
         Collateral.  Without limiting the generality of the foregoing,  Secured
         Party shall be named as a payee on all instruments from insurers of the
         Collateral.  Notwithstanding anything in the foregoing or in Subsection
         (e) above to the  contrary,  Secured  Party agrees that:  (i) insurance
         proceeds  may be paid to Debtor so long as no event of  default  exists
         hereunder and such proceeds are, in aggregate,  less than $500,000; and
         (ii) Secured  Party's rights  hereunder are subject to the interests of
         the parties identified on Schedule A.

              (g)  Records.  Debtor shall keep  accurate  and  complete  records
         pertaining to the Collateral  and  pertaining to Debtor's  business and
         financial condition,  and shall allow Secured Party to inspect the same
         from  time to time  upon  reasonable  request  and  shall  submit  such
         periodic  reports  relating  to the same to Secured  Party from time to
         time as Secured Party may reasonably request. Debtor shall provide that
         the Secured  Party's  interest  is noted on all chattel  paper and that
         there is only one single  original of any chattel  paper held by Debtor
         and created after the date hereof.

              (h) Notice to Secured Party.  Debtor shall promptly notify Secured
         Party of any loss or damage to the  Collateral,  any  impairment of the
         value  thereof,  any claim  made  thereto  by any third  party,  or any
         adverse  change in Debtor's  financial  condition  which may affect its
         prospect to pay or perform its obligations to Secured Party.

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              (i)  Location.  Except for  equipment  or  inventory  provided  to
         Debtor's customers in the ordinary course of business,  Debtor will not
         move the  Collateral,  its chief executive  office,  principal place of
         business or places where it keeps its records concerning the Collateral
         from the locations  specified above without first obtaining the written
         consent of Secured  Party and shall not  permit  any  Collateral  to be
         located  in any  state  in which a  financing  statement  covering  the
         Collateral is required to be, but has not in fact been,  filed in order
         to perfect the  security  interest  granted  herein.  Debtor  shall not
         change its name without giving Secured Party at least ninety (90) days'
         prior notice thereof.

              (j) Other Documents.  Debtor shall execute such further  documents
         as may be requested  by Secured  Party to obtain and perfect a security
         interest  in the  Collateral,  including  without  limitation,  Uniform
         Commercial Code Financing  Statements and amendments thereto. A carbon,
         photographic or other reproduction of this Security Agreement or of any
         financing  statement  signed by Debtor  shall  have the same  force and
         effect as the original for all purposes of a financing statement.

         6.  Default.  Debtor  shall  be in  default  hereunder  if  any  of the
following occurs:

              (a) Event of Default.  An Event of Default occurs under any of the
         Notes or the Loan Agreements.

              (b)  Failure  to Pay.  Debtor  fails to pay when due or within the
         applicable cure period any of the obligations secured hereby.

              (c)  Misrepresentation.  Any of the  representations or warranties
         made by Debtor herein or in any of the documents  referred to herein or
         executed prior hereto or substantially  contemporaneously  herewith are
         or become false or misleading in any material respect.

              (d)  Breach  of  Covenants.  Debtor  fails to  perform  any of its
         covenants,  agreements or  obligations  hereunder or under any document
         referred  to  herein  or  executed   prior   hereto  or   substantially
         contemporaneously herewith.

              (e)  Other  Indebtedness.   Any  event  occurs  which  results  in
         acceleration  of the maturity of the  indebtedness  of Debtor under any
         material agreement with any third party.

              (f) Loss of Security. Collateral with an aggregate value in excess
         of $100,000 is lost, damaged or destroyed.

              (g)  Business  Failure.  The death,  dissolution,  termination  of
         existence,  business failure,  appointment of a receiver of any part of
         the  property  of,  assignment  for the  benefit  of  creditors  by, or
         commencement  of any  proceeding  in  bankruptcy  or  insolvency  by or
         against  Debtor or any  principals of Debtor or any guarantor or surety
         for Debtor.

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         7. Rights and Remedies of Secured  Party.  Secured Party shall have all
of the  rights and  remedies  provided  at law and in equity and in the  Uniform
Commercial  Code and in addition  thereto and without  limitation  thereon shall
have the following rights which may be exercised singularly or concurrently:

              (a)  Inspection.  Secured  Party may at any time,  with or without
         notice,  enter upon  Debtor's  premises  or any other  place  where the
         Collateral is located to inspect and examine the same and, if Debtor is
         in default, to take possession thereof.

              (b)  Performance by Secured Party.  If Debtor fails to perform any
         of  its  obligations   hereunder,   Secured  Party  may,  at  its  sole
         discretion,  pay or perform such  obligations for Debtor's  account and
         may add any cost or expense thereof to the obligations secured hereby.

              (c) Acceleration.  Upon default, Secured Party may, without demand
         or notice to Debtor,  accelerate all of the obligations  secured hereby
         and  proceed  to  enforce  payment  of the same with or  without  first
         resorting against the Collateral.

              (d)  Proceed  Against  Collateral.   Subject  to  applicable  cure
         periods,  if any, upon default,  Secured Party may:  require  Debtor to
         make  the  Collateral  available  to  Secured  Party  at a place  to be
         designated  by  Secured  Party;  take  possession  of  the  Collateral,
         proceeding  without  judicial process or by judicial process (without a
         prior hearing or notice thereof which Debtor hereby  expressly  waives)
         and sell,  retain or  otherwise  dispose of the  Collateral  in full or
         partial satisfaction of the obligations secured hereby.

              (e) Power of Attorney.  Debtor hereby irrevocably  appoints (which
         appointment is coupled with an interest) Secured Party as Debtor's true
         and lawful attorney, with full power of substitution, without notice to
         Debtor  and at  such  time  or  times  as  Secured  Party  in its  sole
         discretion may determine to: (i) create,  prepare,  complete,  execute,
         deliver and file such documents, instruments, financing statements, and
         other  agreements and writings as may be deemed  appropriate by Secured
         Party to facilitate the intent of this Security Agreement;  (ii) notify
         account  debtors and others with  obligations to Debtor to make payment
         of their  obligations  to Secured  Party;  (iii)  demand,  enforce  and
         receive  payment of any  accounts or  obligations  owing to Debtor,  by
         legal  proceedings  or  otherwise;  (iv)  settle,  adjust,  compromise,
         release, renew or extend any account or obligation owing to Debtor; (v)
         notify postal authorities to change the address for delivery of mail to
         Debtor to such address as Secured  Party may  designate;  (vi) receive,
         open and  dispose  of all  mail  addressed  to  Debtor;  (vii)  endorse
         Debtor's name on any check,  note,  draft,  instrument or other form of
         payment that may come into Secured Party's possession;  and (viii) send
         requests to Debtor's  customers and account debtors for verification of
         amounts due to Debtor.  Secured  Party  covenants  not to exercise  the
         foregoing  rights  prior  to the  occurrence  of an  event  of  default
         hereunder.

              (f)  Deficiency.  Upon default,  and after any  disposition of the
         Collateral, Secured Party may sue Debtor for any deficiency remaining.

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         8.  Obligations of Secured  Party.  Secured Party has no obligations to
Debtor  hereunder except those expressly  required  herein.  Except as expressly
provided  in the Loan  Agreements,  Secured  Party  has not  agreed  to make any
further advance or loan of any kind to Debtor. Secured Party's duty of care with
respect to the Collateral in its possession shall be deemed fulfilled if Secured
Party exercises reasonable care in physically  safekeeping the Collateral or, in
the case of Collateral in the  possession of a bailee or third party,  exercises
reasonable  care in the  selection of the bailee or third party.  Secured  Party
need not otherwise preserve, protect, insure or care for the Collateral. Secured
Party  need not  preserve  rights the Debtor  may have  against  prior  parties,
realize on the Collateral in any particular  manner or order,  or apply proceeds
of the Collateral in any particular order of application.

         9. Miscellaneous.

              (a) No Waiver. No delay or failure on the part of Secured Party in
         the exercise of any right or remedy hereunder shall operate as a waiver
         thereof and no single or partial exercise by Secured Party of any right
         or remedy  shall  preclude  other or  further  exercise  thereof or the
         exercise of any other right or remedy.

              (b) Amendment  and  Termination.  This  Security  Agreement may be
         amended or terminated and the security  interest  granted herein can be
         released  only by an explicit  written  agreement  signed by Debtor and
         Secured Party.

              (c)  Choice of Law.  This  Security  Agreement  and the rights and
         obligations of the parties hereto shall be governed by and construed in
         accordance with the laws of the State of Nebraska.

              (d) Binding  Agreement.  This Security  Agreement shall be binding
         upon  the  parties  hereto  and  their  heirs,   successors,   personal
         representatives and permitted assigns.

              (e) Assignment. This Security Agreement may be assigned by Secured
         Party only.

              (f)  Captions.  Captions and headings  herein are for  convenience
         only and in no way define, limit or describe the scope or intent of any
         provision or section of the Security Agreement.

              (g)  Severability.  If any  provision of this  Security  Agreement
         shall be prohibited by or invalid under  applicable law, such provision
         shall be  ineffective  to the extent of such  prohibition or invalidity
         without  invalidating  the remainder of such provision or the remaining
         provisions of this Security Agreement.

              (h) Notices.  All notices to be given shall be deemed sufficiently
         given if delivered or mailed by  registered  or certified  mail postage
         prepaid  if to  Debtor  at Suite  200,  9110 West  Dodge  Road,  Omaha,
         Nebraska  68114;  if to  Secured  Party at One First  National  Center,
         Omaha,  Nebraska  68102;  or such  other  address  as the  parties  may
         designate in writing from time to time.  Debtor shall  promptly  notify
         Secured Party of any changes in Debtor's address.

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              (i) Priorities.  The security interest of a Lender in any property
         of the Debtor (i) arising under and in connection  with the  Agreement,
         this Security  Agreement or any of the Related Loan Agreements and (ii)
         granted  to  secure  any  obligation  of the  Debtor  to  such  Lender,
         including,  without limitation,  all Collateral,  shall rank equally in
         priority with the security  interests of each of the other Lenders,  if
         any, in such  property  of the  Borrower,  irrespective  of the time or
         order of attachment or  perfection  of such security  interest,  or the
         time or order of filing,  or the failure to file, and regardless of the
         date any obligation of the Debtor to a Lender was incurred. Any amounts
         or payments  obtained  upon  disposition  of any  property  securing an
         obligation  of the Debtor to a Lender  shall be applied as  provided in
         Article VII of the 1998 Revolving  Credit Agreement as in effect on the
         date hereof.  Unanimous  approval of the Lenders  shall be required for
         amendments to this Section 9(i).

              IN  WITNESS  WHEREOF,  the  undersigned  have  executed  this 1998
         Security Agreement as of the 7th day of December, 1998.


                                       DATA TRANSMISSION NETWORK CORPORATION


                                       By /s/ Brian L. Larson
                                        Title VP, CFO and Secretary
 
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<PAGE>


                                  FIRST NATIONAL BANK OF OMAHA,
                                  as agent for itself, U.S. Bank,
                                  National Association, First
                                  National Bank, Wahoo,
                                  Nebraska, The First National Bank of Chicago,
                                  Norwest Bank Nebraska, N.A.,
                                  Dresdner Bank AG, New York Branch, Mercantile
                                  Bank of St. Louis, N.A., Bank of Montreal,
                                  LaSalle National Bank, and
                                  National Bank of Canada




                                       By /s/ James P. Bonham
                                        Title Vice President



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<PAGE>

                                    EXHIBIT A
                           TO 1998 SECURITY AGREEMENT
                                 BY AND BETWEEN
            FIRST NATIONAL BANK OF OMAHA, as Agent ("Secured Party")
                                       AND
                DATA TRANSMISSION NETWORK CORPORATION ("Debtor")

                                   COLLATERAL

         All  of  Debtor's  accounts,   accounts   receivable,   chattel  paper,
documents,   instruments,  goods,  inventory,  equipment,  general  intangibles,
contract  rights,  all rights of Debtor in deposits and advance payments made to
Debtor 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/or Farm Dayta  Service to
Debtor's subscribers) and all documentation,  source code, information and works
of authorship  pertaining thereto, all now owned or hereafter acquired by Debtor
and all proceeds and products thereof (including,  without limitation,  all such
assets acquired by Debtor from Broadcast Partners); and

         Further  including,  without  limiting the generality of the foregoing,
the following all now owned or hereafter acquired by the Debtor:

              (a) all accounts,  accounts receivable,  chattel paper, documents,
         instruments,  goods,  inventory,  equipment,  general  intangibles  and
         contract rights that constitute,  are due under or by reason of, or are
         described in,  subscription  agreements or arrangements  between Debtor
         and its subscribers,  and similar agreements or arrangements  purchased
         by Debtor from Broadcast  Partners and including,  without  limitation,
         all:

              (i) equipment and inventory of Debtor,  whether in its  possession
         or in the possession of its customers and  subscribers  (but subject to
         such customers' and subscribers'  rights therein),  which equipment and
         inventory may include, but not be limited to, computer monitor screens,
         D-127,  D-128, D-120, D-110 and 6001 or comparable  receivers,  outdoor
         antennas, and satellite interfaces (collectively, the "Equipment");

              (ii) parts, accessories,  attachments,  additions,  substitutions,
         rents, profits,  proceeds,  products, and customer deposits and advance
         payments related to or arising from the Equipment;

              (iii) chattel paper, instruments,  general intangibles,  accounts,
         accounts   receivable   and  contract   rights  in,   arising  from  or
         corresponding  to the  Equipment,  which may include but not be limited
         to, all rights of Debtor under  Subscription  Agreements between Debtor
         and its customers and subscribers (collectively,  the "Subscriptions");
         and

                                       10
                                    - 703 -
<PAGE>

              (iv) accounts, accounts receivable, rents, profits, modifications,
         renewals, extensions, substitutions,  proceeds, and products related to
         or arising from the Subscriptions; and

              (b) all rights,  remedies,  privileges,  claims and other contract
         rights and general  intangibles  of Debtor  arising under or related to
         the Asset Purchase and Sale Agreement  (including,  without limitation,
         rights to  indemnity)  between  Debtor and  Broadcast  Partners  or the
         transactions contemplated thereby.

              (c) all proceeds and products of the foregoing.




                                       11
                                    - 704 -
<PAGE>

                                   SCHEDULE A
                           TO 1998 SECURITY AGREEMENT
                                 BY AND BETWEEN
            FIRST NATIONAL BANK OF OMAHA, as Agent ("Secured Party")
                                       AND
                DATA TRANSMISSION NETWORK CORPORATION ("Debtor")


                             PERMITTED ENCUMBRANCES


<TABLE>
<CAPTION>
Secured Party                                  Financing Statements

Nebraska Secretary of State

<S>                                            <C>                <C>               <C>
First National Bank of Omaha                   12/28/87           #401690
                                               10/13/92           #564918           Amendment
                                               11/13/92           #568176           Continued
First National Bank of Omaha, as agent           5/8/96           #691938           Amendment

FirsTier, Lincoln                               6/24/87           #384782
First National Bank of Omaha                    2/03/88           #405477           Amendment
First National Bank, Wahoo                      5/28/92           #553205           Continued
NBD, Detroit                                   10/13/92           #564919           Amendment
                                                2/05/93           #576038           Amendment
                                               11/10/93           #603168           Amendment
First National Bank of Omaha, as agent           5/8/96           #691936           Amendment

FirsTier, Lincoln                               2/10/88           #406144
First National Bank of Omaha                   10/13/92           #564917           Amendment
First National Bank, Wahoo                      1/07/93           #572981           Continued
NBD, Detroit                                    2/05/93           #576039           Amendment
                                               11/10/93           #603169           Amendment
First National Bank of Omaha, as agent           5/8/96           #691937           Amendment

First Bank of Minneapolis                      11/25/91           #534665
 (Norstan)                                      8/24/92           #561090           Assignment


Douglas County Clerk, Nebraska

FirsTier, Lincoln                               2/11/88           #000534
First National Bank of Omaha                   10/15/92           #000534           Amendment
First National Bank, Wahoo                      1/08/93           #0000054          Continued
NBD, Detroit                                    2/05/93           #000253           Amendment
                                               11/17/93           #54               Amendment
                                       12
                                    - 705 -
<PAGE>

First National Bank of Omaha, as agent           5/ /96                             Amendment


Iowa Secretary of State

FirsTier, Lincoln                               2/10/88           H842023
First National Bank of Omaha                   10/15/92           K395184           Amendment
First National Bank, Wahoo                      1/08/93           K424887           Continued
NBD, Detroit                                    2/08/93           K434908           Amendment
                                               11/15/93           K503145           Amendment
First National Bank of Omaha, as agent           5/6/96           K734148           Amendment

Kansas Secretary of State

FirsTier, Lincoln                               2/10/88           #1286572
First National Bank of Omaha                   10/15/92           #1842986          Amendment
First National Bank, Wahoo                      1/08/93           #1868482          Continued
NBD, Detroit                                    2/11/93           #1879069          Amendment
                                               11/12/93           #1964342          Amendment
First National Bank of Omaha, as agent          7/18/96           #2265201          Amendment


Illinois Secretary of State

FirsTier, Lincoln                               3/18/88           #2402370
First National Bank of Omaha                   10/21/92           #3043202          Amendment
First National Bank, Wahoo                      2/11/93           #3084199          Amendment
NBD, Detroit                                    2/25/93           #3089132          Continued
                                               12/09/93           #3197498          Amendment
First National Bank of Omaha, as agent           7/9/96           #3562627          Amendment


Michigan Secretary of State

FirsTier, Lincoln                               2/12/88           #C034473
First National Bank of Omaha                   10/16/92           #C646856          Amendment
First National Bank, Wahoo                      1/08/93           #C672590          Continued
NBD, Detroit                                    3/01/93           #C689434          Amendment
                                               11/15/93           #C778208          Amendment
First National Bank of Omaha, as agent           7/8/96           #D128002          Amendment

                                       13
                                    - 706 -
<PAGE>

Wisconsin Secretary of State

FirsTier, Lincoln                               2/18/88           #968701
First National Bank of Omaha                   10/21/92           #1309942          Amendment
First National Bank, Wahoo                     01/15/93           #1326550          Continued
NBD, Detroit                                    2/08/93           #1331412          Amendment
                                               11/23/93           #1393268          Amendment
First National Bank of Omaha, as agent          7/23/96           #1602740          Amendment


Indiana Secretary of State

FirsTier, Lincoln                               2/11/88           #1454192
First National Bank of Omaha                   10/21/92           #1808780          Amendment
First National Bank, Wahoo                      1/11/93           #1822115          Continued
NBD, Detroit                                    2/08/93           #1827451          Amendment
                                               11/12/93           #1878806          Amendment
First National Bank of Omaha, as agent           7/9/96           #2065412          Amendment


Minnesota Secretary of State

FirsTier, Lincoln                               2/17/88           1#121648#00
First National Bank of Omaha                   10/16/92           #1537269          Amendment
First National Bank, Wahoo                     01/19/93           #1557397          Continued
NBD, Detroit                                    2/08/93           #1562125          Amendment
                                               11/23/93           #1632156          Amendment
First National Bank of Omaha, as agent           9/5/96           #1875684          Amendment


South Dakota Secretary of State

FirsTier, Lincoln                               2/10/88           880410802864
First National Bank of Omaha                   10/16/92           #22901003596      Amend.
First National Bank, Wahoo                      1/08/93           #30081001734      Cont.
NBD, Detroit                                    2/09/93           #30391203308      Amend.
                                               11/22/93           #33261003899      Amend.
First National Bank of Omaha, as agent           7/8/96           #961900902562     Amend.


Missouri Secretary of State

FirsTier, Lincoln                               2/11/88           #1555991
First National Bank of Omaha                   10/16/92           #2184193          Amendment
First National Bank, Wahoo                      1/08/93           #2212473          Continued
NBD, Detroit                                    2/08/93           #2224113          Amendment
                                               11/15/93           #2331876          Amendment
First National Bank of Omaha, as agent           7/8/96           #2684601          Amendment

                                       14
                                    - 707 -
<PAGE>

Ohio Secretary of State

FirsTier, Lincoln                               2/12/88           #Y00095612
First National Bank of Omaha                   10/19/92           #01097336         Amendment
First National Bank, Wahoo                      1/11/93           #01119343901      Cont.
NBD, Detroit                                    2/09/93           #02099338901      Amend.
                                               11/12/93           #1129331801       Amendment
First National Bank of Omaha, as agent           7/9/96           #07099607117      Amendment


Kentucky Secretary of State

First National Bank of Omaha                   11/12/93           134318
First National Bank of Omaha, as agent          7/23/96                             Amendment


Pennsylvania Department of State

First National Bank of Omaha                   11/12/93           22571277
First National Bank of Omaha, as agent           7/8/96           25631529          Amendment


Oklahoma Secretary of State

First National Bank of Omaha                    11/12/93           059782
First National Bank of Omaha, as agent            7/8/96           035257           Amendment


Mississippi Secretary of State

First National Bank of Omaha                    11/12/93           0756092--
First National Bank of Omaha, as agent            7/8/96           01015782         Amendment

Colorado Secretary of State

First National Bank of Omaha                    11/12/93           932082461
First National Bank of Omaha, as agent            7/8/96           962051575        Amendment

California Secretary of State

First National Bank of Omaha                    11/12/93           93229491
First National Bank of Omaha, as agent            7/5/96           96191C0067       Amendment


                                       15
                                    - 708 -
<PAGE>

Washington Secretary of State

First National Bank of Omaha                    11/15/93           933190075
First National Bank of Omaha, as agent            7/5/96           96-187-9060      Amendment


Montana Secretary of State

First National Bank of Omaha                    11/15/93           419540
First National Bank of Omaha, as agent            7/8/96           419540           Amendment


Arizona Secretary of State

First National Bank of Omaha                    11/15/93           765359
First National Bank of Omaha, as agent            7/8/96           765359           Amendment


North Carolina Secretary of State

First National Bank of Omaha                    11/15/93           050742
First National Bank of Omaha, as agent            7/8/96           1357308          Amendment


North Dakota Secretary of State

First National Bank of Omaha                    11/16/93           93-380331
First National Bank of Omaha, as agent            7/8/96           96-608985        Amendment


Florida Secretary of State

First National Bank of Omaha                     1/17/93           930000236992
First National Bank of Omaha, as agent           7/10/96           960000142090     Amendment


Texas Secretary of State

First National Bank of Omaha                    11/29/93           227591--
First National Bank of Omaha, as agent            7/8/96           96683548         Amendment


                                       16
                                    - 709 -
<PAGE>

Alabama Secretary of State

First National Bank of Omaha, as agent           6/27/95           B-95-26462FS
                                                 7/19/96           95-26462         Amendment


Arkansas Secretary of State

First National Bank of Omaha, as agent           6/29/95           968722
                                                 7/10/96           968722           Amendment


New York Secretary of State

First National Bank of Omaha, as agent           6/26/95           130246
                                                  7/8/96           532973           Amendment


</TABLE>
                                       17
                                    - 710 -