1997 SECURITY AGREEMENT


         THIS 1997 SECURITY  AGREEMENT  (this  "Security  Agreement") is entered
into as of February 26, 1997, 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"),  NBD
BANK,  a bank  organized  under the laws of the  State of  Michigan  having  its
principal  place of business at 611 Woodward  Avenue,  Detroit,  Michigan  48226
("NBD"),  NORWEST BANK NEBRASKA, N.A., a national banking association having its
principal  place of business at 20th and Farnam Streets,  Omaha,  Nebraska 68102
("Norwest"),  FIRST BANK, NATIONAL  ASSOCIATION,  a national banking association
having its principal place of business at 13th and M Streets,  Lincoln, Nebraska
68508 ("First Bank") (it being  acknowledged that First Bank is the successor in
interest   to   FirsTier   Bank,   National   Association,   Lincoln,   Nebraska
("FirsTier")),  the SUMITOMO BANK, LIMITED, a Japanese bank being represented by
its office at 200 North  Broadway,  Suite 1625,  St. Louis,  Missouri  63102 and
acting through its Chicago branch  ("Sumitomo"),  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 THE BOATMEN'S  NATIONAL BANK OF ST. LOUIS, a national  banking
association  having its principal place of business at One Boatmen's  Plaza, 800
Market Street, P.O. Box 236, St. Louis, Missouri 63166-0236 ("Boatmen's").

                                   WITNESSETH:

         WHEREAS,  Debtor  and  Secured  Party are  parties  to a 1996  Restated
Security  Agreement  dated as of May 3, 1996 as amended by a First  Amendment to
1996 Restated  Security  Agreement dated as of June 28, 1996, a Second Amendment
to 1996  Restated  Security  Agreement  dated as of July 31,  1996,  and a Third
Amendment to 1996 Restated Security Agreement dated as of December 27, 1996, (as
so amended and restated, the "1996 Restated Security Agreement");

         WHEREAS, Debtor and Secured Party wish to further amend and restate the
1996 Restated Security Agreement;

         WHEREAS,  Debtor  and  Secured  Party  wish to have this 1997  Security
Agreement  be the  controlling  agreement  with respect to the matters set forth
herein, which shall supersede the 1996 Restated Security Agreement; and

         WHEREAS,  the  Debtor  and  Secured  Party do not  intend for this 1997
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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                  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 1997  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 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,
FNB-W, Norwest,  NBD, First Bank, Sumitomo,  Mercantile,  Montreal,  LaSalle and
Boatmen's;  (ii) under the 1997 Term Credit Agreement,  dated as of February 26,
1997, between the Debtor and First National Bank of Omaha, FNB-W,  Norwest, NBD,
First  Bank,  Sumitomo,  Mercantile,  Montreal,  LaSalle  and  Boatmen's,  which
agreement further amends and restates the 1996 Term Credit Agreement dated as of
May 3, 1996 among such parties;  (iii) 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,  FNB-W,  Norwest,  NBD,  First  Bank,  Sumitomo,
Mercantile,  Montreal,  LaSalle and Boatmen's; (iv) 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, First National Bank, Wahoo, Nebraska,
FirsTier Bank, National Association,  NBD Bank, Norwest Bank Nebraska, N.A., and
The  Boatmen's  National  Bank of St.  Louis;  (v) 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,  FirsTier Bank,  National  Association,
Lincoln, Nebraska, First National Bank, Wahoo, Nebraska, NBD Bank, N.A., Norwest
Bank Nebraska, N.A. and The Boatmen's National Bank of St. Louis; (vi) under the
Loan  Agreement  dated as of  October 9,  1992,  as  amended  from time to time,
between  Debtor  and First  National  Bank of  Omaha,  FirsTier  Bank,  National
Association,  Lincoln,  Nebraska and First National Bank,  Wahoo,  Nebraska,  or
under any interest rate protection  agreement entered into by Debtor with one or
more Lenders; (vii) 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;  (viii) to reimburse the Secured Party for all sums,
if any, advanced to protect the Collateral;  and (ix) 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;

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                           (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.

                           (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 B 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  other-
wise 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,  $100,000.  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 $100,000 in aggregate net book value of the proceeds of
sale or other disposition of obsolete or

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out-of-date  equipment or inventory  disposed of in accordance  with clause (ii)
above in this Section 5(b).


                           (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 dis-
charge 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
$100,000; and (ii) Secured Party's rights hereunder are subject to the interests
of the parties identified on Schedule B.

                           (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.

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                           (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.

                           (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  represen-
tations 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 aggre-
gate 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  irrevo-
cably 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.


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

                  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 1997  Revolving  Credit  Agreement  as in effect on  February  26,  1997.
Unanimous  approval of the  Lenders  shall be required  for  amendments  to this
Section 9(i).

         IN WITNESS  WHEREOF,  the undersigned  have executed this 1997 Security
Agreement as of this 26th day of February, 1997.


                            DATA TRANSMISSION NETWORK
                            CORPORATION


                            By
                              --------------------------------------------------
                            Title
                                 -----------------------------------------------

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<PAGE>






                            FIRST NATIONAL BANK OF OMAHA,
                            as agent for itself, First Bank,
                            National Association, First
                            National Bank, Wahoo,
                            Nebraska, NBD Bank,
                            Norwest Bank Nebraska, N.A.,
                            The Boatmen's National Bank of
                            St. Louis, The Sumitomo Bank, Limited, Mercantile
                            Bank of St. Louis, N.A., Bank of Montreal, and
                            LaSalle National Bank




                            By
                              --------------------------------------------------
                            Title
                                 -----------------------------------------------

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                                    EXHIBIT A
                           TO 1997 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;


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<PAGE>
                  (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

                  (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

                                    - 251 -
<PAGE>

                                   SCHEDULE A
                           TO 1997 SECURITY AGREEMENT
                                 BY AND BETWEEN
            FIRST NATIONAL BANK OF OMAHA, as Agent ("Secured Party")
                                       AND
                DATA TRANSMISSION NETWORK CORPORATION ("Debtor")


                                 EXISTING NOTES


                                 (See Attached)

                                       12

                                    - 252 -
<PAGE>

                                   SCHEDULE B

                           TO 1997 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
First National Bank of Omaha, as agent                 5/ /96                                 Amendment

                                       13

                                    - 253 -
<PAGE>


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

                                       14

                                    - 254 -
<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.

                                       15

                                    - 255 -
<PAGE>

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


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

                                       16

                                    - 256 -
<PAGE>

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


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                         11/17/93           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

                                       17

                                    - 257 -
<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>


                                       18

                                     - 258 -