<PAGE>
                      AMENDMENT NO. 1 TO SERVICE AGREEMENT

CONFIDENTIAL MATERIALS HAVE BEEN OMITTED FROM THIS EXHIBIT PURSUANT TO A REQUEST
FOR  CONFIDENTIAL  TREATMENT AND HAVE BEEN FILED  SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

                  This Amendment No. 1 to Service  Agreement (this  "Amendment")
is made as of October 22, 1996 (the "Amendment  Effective  Date") by and between
IXC Carrier,  Inc., a Nevada corporation  ("Lessor"),  and Diamond.Net,  I.S.P.,
Inc., a Missouri corporation ("Lessee").

                                   BACKGROUND

                  This Amendment is made with reference to the following facts:

                  A.  Lessee  and Lessor are  parties  to that  certain  Service
Agreement (the "Agreement") dated as of August 15, 1996.

                  B. The parties  desire to amend the Agreement  pursuant to the
terms set forth below.  Each  capitalized  term used and not  elsewhere  defined
herein shall have the meaning set forth for it in the Agreement.

                               TERMS OF AMENDMENT

                  Accordingly, in consideration of the mutual promises set forth
below, the parties hereto hereby agree as follows:

                  1. The  following  paragraphs  are hereby  added to the end of
Section  1.  Scope  and  Rates of the  Agreement  to read in their  entirety  as
follows:

                           Lessee may, at its option,  reconfigure  On-net DS-0,
                  DS-1 or On-net DS-3  Circuits by  disconnecting  such Circuits
                  and simultaneously  ordering new On-net Circuits from Lessor's
                  unused capacity,  but only if all the following conditions are
                  met: (i) such Circuits to be disconnected have been in service
                  at the time of such  reconfiguration for at least three months
                  (for  DS-0  and  DS-1   Circuits)  or  six  months  (for  DS-3
                  Circuits),  (ii) Service  capacity on each such new Circuit is
                  available  from  Lessor  (Lessor  shall  not be  obligated  to
                  construct new Circuit  capacity to fill any Marketing  Service
                  Order);  (iii) Lessee shall pay for such  reconfiguration  the
                  charge  therefore  set  forth  in  Exhibit  B;  and  (iv)  the
                  aggregate  monthly  invoicing  hereunder  for the new Circuits
                  involved in such  reconfiguration must be equal to, or greater
                  than,  the aggregate  monthly  invoicing for the  disconnected
                  Circuits.  Lessee shall have the right to  reconfigure  on-net
                  service and such on-net reconfiguration, so long as it results
                  in an  upgrade  in service  and  revenue  to Lessor,  shall be
                  reconfigured  at * of  the normal  reconfiguration  charges on
                  the ancillary pricing exhibit.

                           Lessor may in the future offer high-capacity services
                  of on-net OC-3C service or larger  capacity  services.  In the
                  event  Lessor   offers

                                       1
* CONFIDENTIAL TREATMENT REQUESTED
<PAGE>


                  such on-net services, Lessee may reconfigure existing circuits
                  into such high-capacity services on mutually agreeable terms.


                           Notwithstanding  the  foregoing  paragraph,  Lessee's
                  existing DS-1 Circuit (the "Existing  DS-1  Circuit")  between
                  St. Louis and Kansas City (No. DNN017903) shall be made a part
                  of a  DS-3  Circuit  ordered  by  lessee  (the  "Ordered  DS-3
                  Circuit")  between St. Louis and Kansas City,  Lessee shall be
                  charged  only for the  Ordered  DS-3  Circuit  and not for the
                  Existing  DS-1 Circuit as of the date the Ordered DS-3 Circuit
                  is activated or the  Amendment  Effective  Date,  whichever is
                  later (the "Start Date"),  and Lessee shall remain responsible
                  for any charges  incurred in connection with the Existing DS-1
                  Circuit prior to the Start Date.

                           Lessee  shall order each of the Circuits set forth in
                  Phase I of  Exhibit E (the  "Phase 1  Circuits")  on or before
                  November  29, 1996 and each of the Circuits set forth in Phase
                  2 of Exhibit E (the  "Phase 2  Circuits")  on or before May 1,
                  1997. Prior to ordering the Phase 2 Circuits, Lessee may elect
                  to  replace  any  of  the  Phase  2  Circuits   with  Circuits
                  originating   and/or  terminating  in  different  cities  (the
                  "Replacement  Phase 2 Circuits")  subject to  availability  by
                  Lessor;  provided,  however,  that  Lessee  shall  pay for the
                  Replacement Phase 2 Circuits at the rates set forth in Exhibit
                  D and the  aggregate  monthly  lease rate for the  Replacement
                  Phase 2  Circuits  must be equal  to,  or  greater  than,  the
                  aggregate  monthly lease rate for the replaced  Circuits.  The
                  monthly  lease rate for each of the Phase I Circuits  shall be
                  $0  for  the  five  month  period  immediately  following  the
                  activation  date of each  Circuit in Phase I (the "Five  Month
                  Free  Period")  and  Lessee's  first  invoice  for the Phase I
                  Circuits  shall be for two  months  Service  for each  Phase I
                  Circuit  and be due  within  the  30  day  period  immediately
                  following  the Five Month Free Period.  The monthly lease rate
                  for the Phase 2 Circuits  shall be $0 for the one month period
                  immediately  following the activation  date of each Circuit in
                  Phase 2 (the "One  Month  Free  Period")  and  Lessee's  first
                  invoice  for  each of the  Phase 2  Circuits  shall be for two
                  months  Service for the Phase 2 Circuits and be due within the
                  30 day period immediately following the One Month Free Period.
                  In the event  Lessor  fails to provide the  Service  within 60
                  days  of the  Requested  Service  Commencement  Date  for  any
                  Circuit,  then (a) Lessee,  at its option,  may terminate that
                  Service  on  the  affected   Circuit   without  any  liability
                  whatsoever  and (b)  Lessee's *  Take-or-Pay  Commitment  (set
                  forth below) shall be reduced by the total  aggregate  monthly
                  lease  rates of the  Circuits  which  could not be supplied by
                  Lessor  within  such  period (the  "Unsupplied  Circuits")  if
                  Lessee  procures the Unsupplied  Circuits from another carrier
                  and provides Lessor with a copy of an invoice from such 2

* CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                  carrier within 90 days from the Requested Service Commencement
                  Date.   Lessor  shall  provide  Lessee  with  Circuit  routing
                  information  for all on-net  Circuits  ordered  hereunder  for
                  Lessee's network planning purposes as soon as such information
                  is available.


                           Lessee shall have a  Take-or-Pay  Commitment of * per
                  month   beginning  July  1,  1997  and  continuing  60  months
                  thereafter (the "Take-or-Pay Commitment Period")."

                  2.  The  following  sentence  is  hereby  added  to the end of
Section 2. Payments of the Agreement to read in its entirety as follows:

                      "Notwithstanding  anything  herein  to  the  contrary,  no
                  termination  of this  Agreement or any Circuit shall affect or
                  reduce   Lessee's   obligation   to  make   the   "Take-or-Pay
                  Commitment"  payments required by Section 1; other than as set
                  forth in Section 1. Scope and Rates above."

                  3. The first  sentence of Section 3. Term of the  Agreement is
hereby amended to read in its entirety as follows:

                      "The term of this  Agreement  shall commence upon the date
                  hereof and shall  continue  until the later of: (i) the end of
                  the  Take-or-Pay  Commitment  Period;  and (ii) the end of the
                  Circuit Lease Term of the Circuit  ordered  hereunder which is
                  last to expire."

                  4. The definition of "Take-or-Pay  Commitment" is hereby added
to the end of Section 6. Definitions of the Agreement to read in its entirety as
follows:

                      "Take-or-Pay  Commitment"  shall mean,  with  respect to a
                  certain  period and amount,  that Lessee has the obligation to
                  pay for Service hereunder in such amount for each month during
                  such period,  whether or not such Service is used. Charges for
                  Services  other than DS-0,  DS-1,  DS-3,  OC type services and
                  monthly  recurring  ancillary  services (such as installation,
                  local  loops and any  other  services)  shall  not be  counted
                  toward the Take-or-Pay Commitment."

                  5. The Non-Recurring Charge for New Order Installation of each
On-Net DS-3 as set forth in Exhibit B of the Agreement is hereby  increased from
* to * and the  following  paragraph  is hereby added to the end of Exhibit B to
read in its entirety as follows:

                      "For purposes of this Exhibit B, "Configuration" means the
                  relative  arrangement,  Phases,  or  connection  pattern  of a
                  circuit and its subcomponent parts/objects;  "Reconfiguration"
                  means any change from

                                       3

<PAGE>

                  the  original  configuration  of a  circuit  specified  in  an
                  original Marketing Service Order;

                      "Cross Connect" means a point in a network where a circuit
                  is connected  from one facility to another by cabling  between
                  the equipment.

                  6. Exhibit D of the Agreement is hereby amended to read in its
entirety as set forth in Exhibit D hereto.

                  7.  Exhibit  E hereto  is  hereby  added to the  Agreement  as
Exhibit E thereto.

                  8. This  Amendment is effective as of the Amendment  Effective
Date.

                  9. To the extent amended hereby, this Amendment supersedes the
Agreement  and any prior  written or oral  agreement  between the  parties  with
respect to the subject matter  contained in this Amendment.  All other terms and
conditions of the Agreement not specifically amended herein shall remain in full
force and effect.

                  IN WITNESS WHEREOF, the parties have executed this Amendment.
<TABLE>
<CAPTION>
<S>                                                           <C>
IXC CARRIER, INC.                                             DIAMOND.NET, I.S.P., INC.

By:   /s/ John R. Flemming                                   By:  /s/ Andrew Gladney
    -------------------------------------------------            -------------------------------------------------
Name:     John R. Flemming                                   Name:   Andrew Gladney
     ------------------------------------------------              ------------------------------------------------
Title:    Executive Vice President                           Title:  President & CEO
      -----------------------------------------------               -----------------------------------------------

-----------------------------------------------------         -----------------------------------------------------
</TABLE>


Approved as to form Legal dept.

                                       4
<PAGE>
<TABLE>
<S>                                          <C>                                  <C>
                                                                                   --------------------------------
Req'st Svc. Date:                                     EXHIBIT A                            OFFICE USE ONLY
                  ----------------                IXC CARRIER, INC.
      Accepted Earlier Activation:            MARKET SERVICE ORDER (MSO)              MSO#
Y       N                                                                                   -------------------
 ------  ----------                                                                --------------------------------
Ckt ID:
        ----------------------

                                PURCHASE ORDER FORM FOR CUSTOMER ORDER NO:
                                                                           ----------------------

Pursuant to the DIGITAL SERVICE AGREEMENT by and between IXC CARRIER, INC.
As LESSOR and                                                                                            as LESSEE,
              ------------------------------------------------------------------------------------------
dated              ,  19  ,  LESSEE orders and LESSOR shall provide the following Digital Transmission Service:
       ------------     --

   New                      Renew                                  Qty        Rate       Term           Miles
           ---------------             --------------
   Cancel                   Disconnect                 DS-3
           ---------------             --------------           ----------  ---------  ----------  ----------------
   Change                   Expedite   Y      N        DS-1
           ---------------              -----  ------           ----------  ---------  ----------  ----------------
   On Net                   Off Net                    DS0
           ---------------             --------------           ----------  ---------  ----------  ----------------
   Protocol                 Reconfigure                CIF
           ---------------             --------------           ----------  ---------  ----------  ----------------
   Other                                               Other
           ------------------------------------------           ----------  ---------  ----------  ----------------

   Customer Contact:                                   Phone #:                        Fax #
                    ---------------------------------          ----------------------        ----------------------
   Technical Contact:                                  Phone #:                        Fax #
                    ---------------------------------          ----------------------        ----------------------
   CITY LOCATION A:                                    CITY LOCATION B:
                    ---------------------------------                  --------------------------------------------
-------------------------------------------------------------------------------------------------------------------
   Special                    Switched                 Special                           Switched
           ----------                    ------------           ----------                         ----------------
   Bypass Y      N            Owner                    Bypass   Y       N                Owner
            ---    ----             -----------------             ----    -----                --------------------
   LESSOR TO PROVIDE:         CFA:       Y     N       LESSOR TO PROVIDE:                CFA:      Y       N
                                           ----  -----                                               -----   ------
   LOA:    Y      N           ASR:       Y     N       LOA:     Y      N                 ASR:      Y       N
             ----  ----                    ----  -----            ----   ----                        ----    ------
   CUSTOMER (LESSEE) TO PROVIDE:                       CUSTOMER (LESSEE) TO PROVIDE:
   LOA:    Y      N      Coordinated Convert Y    N    LOA:     Y      N       Coordinated Convert Y       N
             ----   ----                      ---  ---            ---    ---                         ----    ------
   CIF Arrangement  Y     N     CIF Attach  Y     N    CIF Arrangement  Y      N       CIF Attach  Y       N
                      ---   ---               ---  ---                    ---    ---                 ----    ------
   Special Instructions                  `                      Special Instructions
                        ------------------------------                               ------------------------------


MONTHLY LEASE RATE:                                    NON RECURRING CHARGES:
Monthly IXC Charge:     $                              Installation $                   ASR:      $
                         ----------------                           ----------------              -----------------
Eqpt. Lease Charge:     $                              Installation $                   Reconfig  $
                         ----------------                           ----------------              -----------------
Echo Canceller:         $                              Installation $                   Expedite  $
                         ----------------                           ----------------              -----------------
CIF Racks:              $                              Installation $
                         ----------------                           ----------------
CIF Power:              $                              Installation $
                         ----------------                           ----------------
Other:                  $                              Installation $
                         ----------------                           ----------------
TOTAL:                  $                              TOTAL OF NON RECURRING CHARGES:            $
                         ----------------                                                         -----------------


     Notwithstanding   anything  in  the   Digital   Service Agreement to the contrary,  (1) a security  interest in
     this  Agreement  may be granted by Lessor to any Lender and (2)  Lessor  may from time to time  assign  all its
     rights and  obligations  hereunder  with respect to any Circuits to any Affiliate.  Upon such assignment herein
     this   Agreement   shall  be  deemed  to  be   multiple agreements,  each  upon the terms  and  conditions  set
     forth herein by and between  Lessee and such  affiliate with respect to such circuit  between Lessor and Lessee
     with respect to the circuit not so assigned.


     IN WITNESS  WHEREOF,  the parties have executed this PURCHASE  ORDER on the       day of           19
                                                                                 -----        ---------   --


------------------------------------------------    ------------------------------------------------------------------
     LESSOR APPROVAL/TITLE                             LESSEE AUTHORIZED REPRESENTATIVE/TITLE
     (Service Provider)                                     (Customer)

                                   PLEASE FAX THIS DOCUMENT TO CUSTOMER SERVICE FAX # (512) 328-7810
----------------------------------------------------------------------------------------------------------------------
For Office Use Only Version 2.0    4/11/95
----------------------------------------------------------------------------------------------------------------------
</TABLE>


<PAGE>

                          CUSTOMER MAINTENANCE SUPPORT

         IXC Communications,  Inc.'s  (hereinafter  referred to as IXC) standard
fees for customer  maintenance  support  services are as follows  (unless set by
precedence in a service contract):

         Maintenance  services  shall be defined as all work performed by IXC on
equipment  provided  by or on  behalf of the  Customer,  or  supervision  of the
Customer's work within IXC's terminate  facilities.  Maintenance Service charges
are not billed for troubles  found within that portion of a circuit  provided by
IXC. The following billing rates apply for these services:

                  A. * per  hour (4 hour  minimum  - if  dispatch  is  required)
Monday  through  Friday during the business hours of 8:00 a.m. - 5:00 p.m. local
time, exclusive of the following holidays:

                      New Years Day
                      President's Day
                      Memorial Day
                      Independence Day
                      Labor Day
                      Thanksgiving Day and the day after Thanksgiving
                      Christmas Day

                  B. * per hour (4 hour  minimum) for  overtime  work done after
business hours (defined above) and/or on holidays (defined above) and/or all day
on Saturdays and Sundays.

                  C. As requests for maintenance services are typically made via
telephone,  IXC  must  be  advised,  in  writing  as to the  person(s)  who  are
authorized to request service.  It is the Customer's  responsibility to keep IXC
apprised of any changes to its list of representative(s).

                  D.  To  request  technical   assistance  and  help  under  the
maintenance  services,  a call  must be made to our  Network  Control  Center at
1-800-526-2488.  This  number  should  be  used  for IXC  technical  assistance,
troubleshooting  or testing of circuits,  not for service impairment or outages.
The  person  calling  in must be on the  authorized  list in order to commit for
charges for this  technical  assistance.  If that person is not on the list, the
request cannot be accommodated.

                          1. The Network Control Center  personnel will take the
         call,  record  the  caller's  name and phone  number  along  with facts
         concerning the assistance and support  needed.  The caller will then be
         given the number of the "Assistance Ticket."

                                   Page 1 of 3

  * CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                          2. Upon completion of work, this  "Assistance  Ticket"
         will be given to IXC's  Accounting  Department,  and the customer  will
         subsequently  be billed based upon the  information  on that ticket.  A
         copy will be attached to the invoice.

                  E.  Except  for   emergencies,   IXC  technicians   cannot  be
dispatched  unless  requests  are made in  accordance  with the  above  call-out
procedure.


                                  Page 2 of 3
<PAGE>

                                    EXHIBIT E
                             DIAMONDNET DS3 CIRCUITS

<TABLE>
<CAPTION>
                                              Rate Section
        ---------------------------------------------------------------------------------------------
                                                       V&H      Banded
            City A         City B       Availability   Miles  $250k Rate    Monthly    Installation
-----------------------------------------------------------------------------------------------------
<S>     <C>            <C>                 <C>          <C>    <C>          <C>          <C>
   P    St. Louis      Kansas City         Normal       208    *                *        $2,000
   H    Chicago        Detroit             Normal       207    *                *        $2,000
   A    Detroit        Pittsburgh          Normal       206    *                *        $2,000
   S    Pittsburgh     New York            Normal       318    *                *        $2,000
   E    New York       Philadelphia        Normal        34    *                *        $2,000
        Philadelphia   Washington, DC      Normal       124    *                *        $2,000
   1    Washington, DC Atlanta             Normal       541    *                *        $2,000
        Atlanta        Houston             Normal       702    *                *        $2,000
        Houston        Austin              Normal       144    *                *        $2,000
        Dallas         Phoenix         12/31/96 Note**  888    *                *        $2,000
        Phoenix        Los Angeles     2/28/97 Note**   359    *                *        $2,000
        Total                                                                   *

<CAPTION>
                 Rate Section                                   Billing Summary
        -----------------------------------------------------------------------------------------------------
                                                                                           Month    Month 7
            City A         City B      Month 1   Month 2   Month 3    Month 4   Month 5      6      thru 65
-------------------------------------------------------------------------------------------------------------
<S>     <C>            <C>             <C>       <C>       <C>        <C>       <C>        <C>      <C>
   P    St. Louis      Kansas City
   H    Chicago        Detroit
   A    Detroit        Pittsburgh
   S    Pittsburgh     New York
   E    New York       Philadelphia
        Philadelphia   Washington, DC
   1    Washington, DC Atlanta
        Atlanta        Houston
        Houston        Austin
        Dallas         Phoenix
        Phoenix        Los Angeles
        Total                               *        *          *         *          *      *        *



Note:  Above rates under Phase 1 offer are provided with the following terms and conditions.
       o     Total contract term of 65 months for each circuit provided.                -------------------------------------------
       o     Billing during the first five months is *.                                 Five Months of Billing                    *
       o     Billing  from 5th month forward is Monthly  recurring  plus monthly        60 Months Amortize                        *
             amortized  amount of first five  months.                                   -------------------------------------------
       o     All circuits of Phase 1 must be ordered as a package.
       o     Normal  Availability is approximately 30 days after receipt of firm
             order.

       ** If the availability of the  Dallas-Phoenix or the Phoenix-Los  Angeles
       circuit is  unsatisfactory,  they can be deleted from this Phase  without
       penalty.

<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------

   P    Los Angeles    Santa Clara         Normal       313    *               *         $2,000
   H    Santa Clara    San Francisco       Normal        38    *               *         $2,000
   A    San Francisco  Salt Lake           Normal       598    *               *         $2,000
   S    Salt Lake      Denver              Normal       370    *               *         $2,000
   E    Denver         Kansas City         Normal       558    *               *         $2,000
        Atlanta        Miami               Normal       600    *               *         $2,000
   2    Chicago        New York            Normal       712    *               *         $2,000
        Total                                                                  *

<CAPTION>
---------------------------------------

   P    Los Angeles    Santa Clara
   H    Santa Clara    San Francisco
   A    San Francisco  Salt Lake
   S    Salt Lake      Denver
   E    Denver         Kansas City
        Atlanta        Miami
   2    Chicago        New York
        Total                               *     *          *         *          *          *      *

Note:  Above rates under Phase 2 offer are provided with the following terms and conditions:
 o     Total contract term of 81 months for each circuit provided.                ----------------------
 o     All circuits of Phase 2 must be ordered as a package.                      One Month of Billing *
 o     All  circuits of Phase 1 must be ordered to quantity for Phase 2 circuits. 60 Months Amortize   *
 o     Billing during first month is *.                                           ----------------------
 o     Billing from 2nd month forward is Monthly recurring plus amortized amount of first month.
 o     Normal Availability is approximately 30 days after receipt of firm order.
-----------------------------------------------------------------------------------------------------------------------------------
* CONFIDENTIAL TREATMENT REQUESTED
</TABLE>

                                  Page 3 of 3
<PAGE>

                                    EXHIBIT D

                            List of Rates for Service
                            -------------------------

DS-0 Service                                                      *

DS-1 Service                                                      *

DS-3 Service

                         Term                  Miles          Rate per DS-0 Mile
                         ----                  -----          ------------------

       ON-NET                                 0 - 250               *
       PHASE 1         65 months
                                             251 - 500              *
       OFF-NET                              501 - 1,000             *
       PHASE 2         61 months
                                              1,000+                *

* CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

<TABLE>
<CAPTION>
INSTALLED DS-0 CITIES                                                                                 OCTOBER, 1996
<S>                                      <C>            <C>                                      <C>
ARIZONA                                  NPA/NNX        TEXAS NPA/NNX
      Phoenix                            602-279              Austin                             512-389
                                                              Corpus Christi                     512-883
CALIFORNIA                                                    Dallas                             214-741
      Los Angeles                        213-622              El Paso                            915-533
      San Diego                          619-419              Fort Worth                         817-777
      Stockton                           209-463              Harlingen                          210-425
                                                              Houston                            713-224
DISTRICT OF COLUMBIA                                          San Antonio                        210-222
      Washington, DC                     202-245              McAllen                            210-632

ILLINOIS                                                VIRGINIA
      Chicago                            312-861              Norfolk                            804-622

MARYLAND                                                TOTAL DS-0 CITIES                        26
      Baltimore                          410-752
                                                        All cities are equipped for DSO services.
MICHIGAN
      Birmingham                         313-435        Additional cities will be added if cost is justified.

MISSOURI
      Kansas City                        816-221
      St. Louis                          314-231

NEW MEXICO
      Albuquerque                        505-247

NEW YORK
      New York City                      212-285

OHIO
      Dayton                             513-252

OKLAHOMA
      Oklahoma City                      405-232
      Tulsa                              918-582

PENNSYLVANIA
      Philadelphia                       215-988
</TABLE>

<PAGE>

                                    EXHIBIT C

                           ON-NET DS-1 AND DS-3 CITIES

<TABLE>
<CAPTION>
<S>                                    <C>                                       <C>
ARIZONA                                DISTRICT OF COLUMBIA                      Flint
  Phoenix  LATA 666                      Washington, D.C.  LATA 236                2001 S. Grand Traverse
    Phelps-Dodge Twr, Ste 1702             1828 L Street, N.W., Ste 260              (313)767
    2600 N. Central (602)279                 (202)833
                                                                                 Grand Rapids
  Tucson  LATA 668                     ILLINOIS                                    209 Graham, S.W.
    Arizona Bank Bldg.                   Chicago  LATA 358                           (616)235
    33 N. Stone, Suite 1610                Prudential Building
      (520)792                             130 E. Randolph, Suite 4001           Jackson
                                             (312)861                              170 W. North Street
CALIFORNIA                                                                           (517)783
  Bakersfield  LATA 734                INDIANA
    1430 Truxton Ave., Ste 730           Indianapolis  LATA 336                  Kalamazoo
      (805)327                             Merchants Bank Bldg.                    303 Mills St.
                                           11 S. Meridian                            (616)385
  Fresno  LATA 728                         Suite 1798/1799
    4605 E. Vine                             (317)637                            Lansing
      (209)486                                                                     230 South St.
                                       Southbend  LATA 332                           (517)482
  Fresno Ter                               211 West Washington St.
    Guarantee Savings                      19th Floor                            Midland
    B1171 Fulton Mall, Ste. 1201             (219)233                              1000 Jefferson
      (209)268                                                                       (517)631
                                       MARYLAND
  Los Angeles  LATA 730                  Baltimore  LATA 238                     Pontiac
    One Wilshire                           1220 S. Howard                          324 S. Saginaw
    624 S. Grand, Suite 1615                 (301)752                                (313)338
      (213)689
                                       MICHIGAN                                  Royal Oak
  San Diego  LATA 732                    Ann Arbor                                 3100 W. 14 Mile Rd.
    8933 Complex Dr.                       1615 Plymouth Rd.                         (313)435
      (619)569                               (313)994
                                                                                 Saginaw
  San Francisco  LATA 722                Battle Creek                              315 Meredith
    Metropolitan Life Bldg.                175 Main Street                           (517)771
    425 Market St, Ste 3800C                 (616)962
      (415)543                                                                 MISSOURI
                                         Bay City                                Kansas City  LATA 524
  Sunnyvale  LATA 722                      100 E. Hart                             Bank of Kansas City
    111 Uranium                              (517)667                              1125 Grand Ave., Suite 1704
      (408)739                                                                       (816) 283
                                         Detroit  LATA 340
COLORADO                                   Book Bldg. Suite 2609                 St. Louis  LATA 520
  Colorado Springs  LATA 658               1249 Washington Blvd.                   900 Walnut, Suite 220
    102 S. Tejon, Suite 780                  (313)961                                (314)231
      (719)471
                                         Detroit                               NEVADA
  **Denver  LATA 656                        1860 Gratiot Ave.                    **Las Vegas LATA 821
    Bell Building                            (313)259                              Centel Bldg, Ste 400
    931 14th Street, Ste. 622                                                      125 S Las Vegas Blvd.
      (303)572                                                                       (702)388
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
<S>                                    <C>                                       <C>
NEW JERSEY                               Tulsa  LATA 538                           Harlingen  LATA 568
  Newark  LATA 224                         Lookout Mountain                          513 E. Jackson
    744 Broad Street, 3rd Floor            3500 S. 26th West Avenue                  Matz Building
      (201)824                               (918)584                                  (210)425
                                             (918)446
NEW MEXICO                                                                         Houston  LATA 560
  Albuquerque  LATA 664                PENNSYLVANIA                                  293 N. Main Street
    200 Lomas Blvd, N.W.                 Philadelphia  LATA 228                        (713)224
    13th Floor                             2401 Locust St., 2nd Floor
      (505)247                               (215)564                              Lubbock  LATA 544
                                                                                     1220 Broadway, #1901
NEW YORK                                 Pittsburgh  LATA 234                          (806)762
  New York  LATA 132                       Oliver Building
    60 Hudson St., Ste 206                 535 Smithfield St., Ste 2650            McAllen  LATA 568
      (212)285                               (412)281                                200 S. 10th Street, Suite 704
                                                                                       (210)687
OHIO                                   TEXAS
  Akron  LATA 325                        Abilene  LATA 550                         Midland  LATA 542
    1 Cascade Plaza, Ste 1950              1049 N. Third, Suite 500                  KMID-TV Studio
    Main & Bowery                            (915)675                                La Force Blvd &
      (216)535                                                                       Air Terminal
                                         Amarillo  LATA 546                            (915)561
  Cincinnati  LATA 922                     Amarillo Petroleum Bldg.
    2300 Carew Tower                       203 W. 8th, Suite 607/608               San Angelo  LATA 961
    Suite 4701                               (806)373                                36 E. Twohig, 15th Floor
    441 Vine St. (513)651                                                              (915)653
                                         Austin  LATA 558
  Cleveland  LATA 320                      621 Pleasant Valley Road                San Antonio  LATA 566
    R.F. Keith Bldg., Suite 2117             (512)389                                660 S. Santa Rosa
    1621 Euclid Ave.                                                                   (210)225
      (216)771                           Corpus Christi  LATA 564
                                           606 N. Carancahua, Ste 816              Waco  LATA 556
  Columbus  LATA 324                       Wilson Plaza                              100 S. 26th Street
    Borden Bldg., Level 2B                   (512)882                                  (817)750
    180 E. Broad St.
      614(469)                           Dallas  LATA 552                       **Priced on an Individual Case Basis (ICB)
                                           Tower of the Americas
  Dayton  LATA 328                         2323 Bryan, Suite 380
    1 National Bank Bldg.
    Suite 2220                             2223 Houston St.
    130 W. Second (513)461                 (214)954 (214)969

  Toledo  LATA 326                       El Paso  LATA 540
    319 Madison Ave., Ste 2901             El Paso National
      (419)242                             Bank Bldg.
                                           201 E. Main, Suite 1702
OKLAHOMA                                     (915)533
  Oklahoma City  LATA 536
    Liberty Tower                        Fort Worth  LATA 552
    100 N. Broadway, Ste 3020              WT Waggoner Blvd.
      (405)232                             810 Houston, Suite 1705
                                             (817)870
</TABLE>

<PAGE>


<TABLE>
<CAPTION>
                                             ANCILLARY PRICING SCHEDULE FOR ON-NET SERVICE

NON-RECURRING CHARGES                                                DS-1                    DS-3
---------------------                                                ----                    ----
<S>                                                                  <C>                     <C>
New Order Installation (On-Net)                                        *                      *

New Order Installation (Off-Net)                                       *                      *

DS-1 Ramp-Up per DS-O                                                  *                      *

Order Change (less than 5 business days)                               *                      *

Order Cancellation (less than 5 business days)                         *                      *

ASR (new or disconnect) (Special Access Only)                          *                      *

ASR Supplement                                                         *                      *

Order Expedite                                                         *                      *

Reconfiguration                                                      Same as install         Same as install

<CAPTION>
MONTHLY RECURRING CHARGES                                            DS-1                    DS-3
-------------------------                                            ----                    ----
<S>                                                                  <C>                     <C>
Monthly circuit charge (IXC portion)                                    *                      *

Cross-connect charge                                                    *                      *
    Other Interexchange Carrier to Lessor local access
    or bypass facility (Lessor long haul not involved)

Local bypass charge                                                     *                      *
    Lessor POP to Lessor POP in same city, with no
    Lessor long haul attached at either Lessor POP.

<CAPTION>
MISCELLANEOUS                                                        RECURRING               NON-RECURRING
-------------                                                        ---------               -------------
<S>                                                                  <C>                     <C>
M13 1 yr Term                                                           *                         *
    2+yr Term                                                           *                         *
    3+yr Term                                                           *                         *
ECHO CANCELLER (per circuit end)                                        *                         *
SECOND END LOOP (Ex: for ADPCM)                                         *                         *
DEMAND MAINTENANCE                                                   * /hr 8a.m.-5p.m. M-F, 4 hour minimum
                                                                     if dispatch is required;  *  /hr after hours
                                                                     with 4 hour minimum
RACK SPACE                                                           * - subject to availability
SHELF SPACE                                                          * /ea/mo              ICB install
DC POWER                                                             * /amp/mo (5 amp minimum; 5 amp
                                                                     increments)
CIF AC/DC POWER                                                      *
ALL OTHER SERVICES                                                   See Note (2)
</TABLE>

(1)   All of the above charges are subject to change with a 30-day notice.
(2)   Services  not  described  above will be  considered  special  handling and
      charges will be assessed on an individual basis.

* CONFIDENTIAL TREATMENT REQUESTED