<PAGE>   1
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.
                         
                                                                EXHIBIT 10.30 
                           MASTER SERVICES AGREEMENT            

     This MCI Master Service Agreement, including the Schedules attached hereto
     ("Agreement") is made between MCI Telecommunications Corporation and its
     affiliates ("MCI") and Verio, Incorporated ("Customer"), and shall be
     binding when executed by both Parties and the conditions set forth in
     paragraph 11(m) below (*) and paragraph 11(n) with respect to credit
     approval have been satisfied.

     The Term, rates, discounts and certain other provisions applicable to MCI
     tariffed services ("Tariffed Services") are set forth in Schedule I and its
     Attachments (hereby incorporated by reference) and shall be effective on
     the Attachment Effective Date, as set forth in Attachment A to Schedule I.
     The Term, rates, discounts and certain other provisions applicable to MCI
     non-tariffed services ("Enhanced Services") are set forth in Schedule II
     and its Attachments (hereby incorporated by reference) and shall be
     effective on the Schedule Effective Date, as set forth in Schedule II. The
     MCI Enhanced Services provided under Schedule II and its Attachments will
     not receive the rates, discounts and credits provided under Schedule I, nor
     will Enhanced Service usage be included in determining the rates, discounts
     and credits provided under Schedule I.

     For good and valuable consideration, the sufficiency of which is hereby
     acknowledged, and intending to be legally bound, MCI and Customer (each a
     "Party" and together, the "Parties") agree as follows:

1.   Authority. Each Party represents and warrants that it has the full right,
     power and authority to enter into this Agreement, to perform its
     obligations hereunder and that the execution, delivery and performance of
     this Agreement will not conflict with or constitute a default under any
     contract, agreement or other obligation to which it is subject.

2.   Confidential Information. The Parties agree that any confidential
     information disclosed during performance of this Agreement shall be
     governed by the Non-Disclosure Agreement ("NDA") between the Parties dated
     May 19, 1997. The parties further agree that this Agreement, its Schedules
     and Attachments are confidential information under the terms of the NDA and
     that notwithstanding anything to the contrary, the term of the NDA is
     hereby amended to be coterminous with this Agreement.

3.   Termination of Schedules and Attachments. In addition to any other
     termination rights identified in the attached Schedules, the Parties agree
     that if all Schedules and Attachments hereto have been terminated in
     accordance with the termination provisions set forth therein, then this
     Agreement shall terminate, effective as of the termination date of the last
     remaining Schedule or Attachment.

4.   Provision of MCI Services.

          (a) Pass-Through Charges. For all domestic and international access
     services provided in conjunction with the MCI services provided under this
     Agreement, MCI shall pass through to Customer and Customer shall pay any
     charges, fees, taxes and otherwise be subject to terms and conditions of
     service imposed by access suppliers, including those pertaining to rate
     fluctuations in


                                MCI CONFIDENTIAL
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<PAGE>   2



     telephone tariffs, and charges that are imposed or enacted by access
     suppliers to MCI after the execution of this Agreement.

          (b) Settlement Gains or Losses. If the charges of international
     telecommunications operators (ITO's) or other third party service providers
     are billed to Customer on a pass-through basis, the charges payable to the
     ITO or third party service provider will be converted to U.S. Dollars at
     the exchange rates applicable for billing in a foreign currency stated
     above. The payments to the ITO's or third parties are generally made at the
     end of the month. Any difference between the amount billed and the
     equivalent U.S. Dollar amounts paid will be included in a subsequent
     period's invoice as loss or gain on settlements.

5.   MCI Invoices and Payment.

          (a) Payment of MCI Invoices. All amounts due for MCI services provided
     under this Agreement shall be billed and paid in U.S. Dollars. Customer
     shall pay MCI for such services within thirty (30) calendar days after the
     date of MCI's invoice. Independent of such payment obligation, Customer
     shall make a separate claim in writing, with adequate support, for any
     credit for service interruption to which Customer believes itself entitled
     under this Agreement, and MCI and Customer will promptly address and
     resolve the claim. Failure of MCI to invoice Customer in a timely manner
     for any amounts due hereunder shall not be deemed a waiver by MCI of its
     rights to payment therefor.

          (b) Taxes. Except as otherwise indicated herein, the charges specified
     in the Schedules or Attachments do not include, and Customer agrees to pay,
     all taxes levied by any duly constituted taxing authority against or upon
     MCI provided services or otherwise arising out of this Agreement
     (including, without limitation, any sales, gross receipts or value-added
     taxes), except any such income tax based on or measured in whole or in part
     by gross or net income, gross or net payments, profits, or net worth of MCI
     or its affiliates (the "Taxes"); so long as, in the case of foreign tax
     withholdings, Customer shall agree to cooperate with MCI in providing
     foreign tax receipts to MCI; utilize best efforts to comply with foreign
     tax laws; and utilize best efforts to provide MCI and/or a foreign taxing
     authority with additional information to support MCI's claim for foreign
     tax credit(s), as requested in writing by MCI.

6.   Customer Obligations.

          (a) Customer-Obtained Equipment, Services and Interconnections. Unless
     otherwise specified in this Agreement, Customer shall be responsible for
     obtaining, installing, and maintaining all equipment, software and/or
     communications services necessary for interconnection with MCI's network or
     otherwise for use in conjunction with the applicable MCI provided service.
     MCI will provide Customer with manufacturer-provided technical information
     concerning MCI provided equipment and standard configuration information
     with respect to MCI's network to allow Customer to obtain, install and
     maintain the equipment, software and/or communications services. Except for
     any equipment specified by MCI, Customer shall have sole responsibility for
     ensuring that such equipment, software and/or services are compatible with
     MCI's requirements and that they continue to be compatible with subsequent
     revision levels of


                                MCI CONFIDENTIAL
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<PAGE>   3



     MCI provided equipment, software and services. Unless otherwise expressly
     agreed in writing, MCI shall have no responsibility for the availability,
     capacity and/or condition of any equipment, software or services not
     provided by MCI under this Agreement. Should Customer undertake to connect
     any MCI products or services to any third party service or network,
     Customer shall indemnify and hold harmless MCI from any damages, costs,
     liabilities and expenses resulting from such connection or attempted
     connection, including but not limited to damages resulting from
     unauthorized use of, or access to, MCI's network.

          (b) Security. Customer shall, at its own expense, take all
     commercially reasonable security measures with respect to physical and
     information systems necessary to protect all equipment, software, data and
     systems located on Customer's premises or otherwise in Customer's control
     and used in connection with the MCI provided services, whether owned by
     Customer, MCI, or MCI's subcontractors. Customer acknowledges and agrees
     that MCI shall not be liable, either in contract or in tort, for any loss
     resulting from any unauthorized access (other than that caused by MCI
     agents, employees or subcontractors in performance of the Agreement) to,
     or alteration, theft, destruction, corruption, or use of, equipment,
     software, data, or systems used in connection with MCI services.

            (c) Access to Customer Sites. Customer agrees to provide MCI and its
     subcontractors and their respective employees and agents access to
     Customer's sites where any MCI services are provided (including access to
     associated equipment) as necessary for MCI and its subcontractors to
     perform MCI services.

7.   Services, Software and Documentation. MCI is not required to provide
     software and/or documentation to the Customer under this Agreement.
     However, if during the term of this Agreement the Parties determine
     that software and/or documentation is to be provided to the Customer, then
     the Parties agree to negotiate in good faith appropriate terms and
     conditions associated with the rights to such software and/or
     documentation.

8.   Indemnify by Customer. Customer agrees to indemnify MCI and its affiliates
     and their respective employees, officers, directors, agents and
     subcontractors, and hold them harmless against any damages including those
     for personal injury and property damage and expenses incurred by any of
     them arising out of Customer's acts, omissions and/or breach of its
     obligations hereunder, and/or Customer's use of MCI provided services in a
     manner other than as contemplated herein, including without limitation use
     that gives rise to claims for libel, slander, invasion of privacy, or
     infringement of any patent, copyright, trademark, or other proprietary
     right of a third party; provided, however, that Customer's obligations
     hereunder shall not apply (i) to the extent the same arise out of or in
     connection with MCI's modification of a program or a machine provided by
     Customer or MCI's combination, operation or use of a program or machine
     provided by Customer with devices, data or programs not furnished by
     Customer or its subcontractors; or, (ii) to claims of infringement of any
     patent, copyright, trademark or other proprietary right of a third party
     arising from Customer's use of MCI provided software hardware. Customer's
     obligations pursuant to this Section shall be subject to: (i) MCI notifying
     Customer in writing as to any such claim, suit, action or other proceeding
     promptly after MCI becomes or reasonably should have become aware of the
     same; (ii) at the request of Customer,


                                MCI CONFIDENTIAL
                                        3

<PAGE>   4



     providing to Customer all information and assistance reasonably necessary
     to Customer in the settlement and/or defense of the same; and (iii)
     affording Customer sole control of the settlement and/or defense of the
     same.

9.   Compliance. Customer is responsible for complying with all local license or
     permit requirements, and all laws and regulations, including but not
     limited to export, import and customs laws and regulations. MCI shall
     provide reasonable assistance to Customer and its affiliates to facilitate
     such compliance. Such assistance may include preparation of import and
     customs forms and/or, where requested by Customer, acting as Customer's
     agent in the import process.

10.  Disclaimer of Certain Damages. EXCEPT AS AWARDED AS PART OF A JUDGMENT OR
     SETTLEMENT FOR THIRD PARTY CLAIMS COVERED UNDER SECTION 8, NEITHER PARTY
     SHALL BE LIABLE TO THE OTHER FOR ANY CONSEQUENTIAL, EXEMPLARY, SPECIAL,
     INCIDENTAL OR PUNITIVE DAMAGES ARISING FROM THIS AGREEMENT, THE SCHEDULES
     AND THE ATTACHMENTS, EVEN IF IT HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     DAMAGES.

11.  Miscellaneous

     (a) Assignment. Neither Party may assign this Agreement, or any of its
rights or obligations hereunder, without the prior written consent of the other
Party, which consent shall not be unreasonably withheld. Any attempted
assignment without such prior written consent shall be void. Notwithstanding the
foregoing, MCI may assign this Agreement, or any of its rights or obligations
thereunder, to its parent or any of its wholly-owned subsidiaries or affiliates.

      (b) Project Management/Dispute Resolution. Project Management/Dispute
Resolution shall be as follows:

          (1) Promptly following execution of this Agreement, each Party shall
              name a Project Manager who shall be responsible for day-to-day
              implementation and management of the project.

          (2) Each Project Manager shall provide written notification to the
              other in the event of any dispute arising from performance of
              this Agreement, such notification to be tendered within a
              reasonable time frame. Promptly following notification of any
              such dispute, the Project Managers shall meet (if requested to do
              so) and shall negotiate in good faith in an attempt to resolve
              such dispute.

          (3) If after good-faith negotiations the Project Managers shall be
              unable to resolve any such dispute, then either Project Manager
              may escalate resolution of the dispute to the following level of
              personnel who, within ten (10) days of notice of such escalation,
              shall meet (if requested to do so) and negotiate in good faith to
              resolve such dispute:


                                MCI CONFIDENTIAL
                                       4

<PAGE>   5
              For MCI:             Jerry Edgerton                    
                                   Vice President                    
                                   MCI Telecommunications Corporation
                                   8200 Greensboro Dr.               
                                   McLean, VA 22102                  
                                   Fax: (703) 902-6101               
                                                                     
              For Customer:        Chris DeMarche                    
                                   Chief Technology Officer          
                                   Verio, Incorporated               
                                   9250 East Costilla Avenue         
                                   Suite 400                         
                                   Englewood, CO 80112               
                                   Fax: (303) 792-3869               
                                                             
                                                             

          (4) If after good-faith negotiations the Parties still are unable to
              resolve the dispute, then either Party may escalate resolution of
              the dispute to the following who, within ten (10) days of notice
              of such escalation, shall meet (if requested to do so) and
              negotiate in good faith to resolve such dispute:

              For MCI:             Robert Hartnett
                                   President
                                   MCI Telecommunications Corporation
                                   3 Ravinia Drive
                                   Atlanta, GA 30346-2102
                                   (770) 280-6113

              For Customer:        Justin Jaschke
                                   Chief Executive Officer   
                                   Verio, Incorporated       
                                   9250 East Costilla, Avenue
                                   Suite 400                 
                                   Englewood, CO 80112       
                                   Fax: (303) 792-3869       

          (5) Any dispute arising out of or related to this Agreement, which
              cannot be resolved by negotiation, shall be settled by binding
              arbitration in accordance with the J.A.M.S/ENDISPUTE Arbitration
              Rules and Procedures ("Endispute Rules"), as amended by this      
              Agreement. The costs of arbitration, including the fees and
              expenses of the arbitrator, shall be shared equally by the
              Parties unless the arbitration award provides otherwise. Each
              Party shall bear the cost of preparing and presenting its case.
              The Parties agree that this provision and the Arbitrator's
              authority to grant relief shall be subject to the United States
              Arbitration Act, 9 U.S.C. 1-16 et seq. ("USAA"), the provisions
              of this Agreement, and the ABA-AAA


                                 MCI CONFIDENTIAL
                                            5


<PAGE>   6



              Code of Ethics for Arbitrators in Commercial Disputes. The
              Parties agree that the arbitrator shall have no power or
              authority to make awards or issue orders of any kind except as
              expressly permitted by this Agreement, and in no  event shall the
              arbitrator have the authority to make any award that provides for
              punitive or exemplary damages. The Arbitrator's decision shall
              follow the plain meaning of the relevant documents, and shall be
              final and binding. The award may be confirmed and enforced in any
              court of competent jurisdiction. All post-award proceedings shall
              be governed by the USAA.

      (c) No Waiver. Neither Party's failure, at any time, to enforce any right
or remedy available to under this Agreement shall be construed to be a waiver of
such Party's right to enforce each and every provision of this Agreement in the
future.

      (d) Force Majeure. Any delay in or failure of performance by either Party
under this Agreement (other than a failure to comply with payment obligations)
shall not be considered a breach of this Agreement if and to the extent caused
by events without the fault and beyond the reasonable control of the Party
affected, including but not limited to acts of God, embargoes, governmental
restrictions, strikes (other than those affecting only Customer), subcontractor
failures or delays, riots, wars or other military action, civil disorders,
rebellion, vandalism, or sabotage. Market conditions and/or fluctuations
(including a downturn of Customer's business) shall not be deemed force majeure
events. The Party whose performance is affected by such events shall promptly
notify the other Party, giving details of the force majeure circumstances, and
the obligations of the Party giving such notice shall be suspended during but
not longer than the continuance of the force majeure, and the time for
performance of the affected obligation hereunder shall be extended by the time
of the delay caused by the force majeure event.

      (e) Trademarks. Except as otherwise expressly provided in this Agreement,
nothing in this Agreement shall create in either Party any rights in any
trademark, trade name, service mark, insignia, symbol, identification and/or
logotype of the other Party. Before either Party uses any such mark of the other
Party, it shall obtain the prior written consent of the other Party.

      (f) Export Controls. The Parties acknowledge that certain equipment,
software and technical data which may be provided hereunder may be subject to
export and re-export controls under the U.S. Administration Regulations and/or
similar regulations of the U.S. or any other country. No Party shall export or
re-export any such equipment, software, technical data or any direct product
thereof in violation of any such laws.

      (g) Foreign Corrupt Practices. Customer agrees that neither it nor any of
its directors, officers, employees, subcontractors or agents will make any
offer, payment, promise to pay or authorization of the payment of any money,
offer, gift, promise to give, or authorization of the giving of anything value
to any official, political party, party official or political candidate or any
person, knowing that all or a portion of such money or thing of value will be
offered, given or promised, directly or indirectly to any official, political
party, party official or political candidate, for the purpose of retaining
business for or with, or directing business to Customer or MCI. As used in this
Section the term "official" refers to any officer or employee in private or
public


                                MCI CONFIDENTIAL
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<PAGE>   7



service and includes any officer or employee of a government, or any department,
agency or instrumentality thereof, or any person acting in such an official
capacity for or on behalf of any such government or department, agency or
instrumentality thereof.

      (h) Governing Law. This Agreement, and all causes of action arising out of
this Agreement, shall be subject to the Communications Act of 1934, as amended
or succeeded (the "Act"), or, to the extent that any part of this Agreement is
not governed by the Act, by the domestic law of the State of New York without
regard to its choice of law principles. In the event of a conflict between this
Agreement and any subsequent translations, this English language version shall
prevail.

      (i) Notices. Any notice or other communication required to be given to the
other Party under this Agreement shall be given in writing, in the English
language and either (1) delivered in person, (2) sent by United States certified
or registered mail, postage prepaid, or (3) sent by an overnight courier
service, to the following addresses:


  If to MCI:

               MCI Telecommunications Corporation
               8200 Greensboro Drive
               McLean, VA 22102
               Attn: Jerry A. Edgerton, Vice President
               With a Copy To: Law and Public Policy (same MCI
               address as above)

  If to Customer:

               Verio, Incorporated
               9250 East Costilla Avenue
               Suite 400
               Englewood, CO 80112
               Attn: Mr. Chris DeMarche,
                     Chief Technical Officer

The name and address for notice may be changed by giving written notice in
accordance with this Section. If mailed in accordance with this Section, notice
shall be deemed given three (3) days after mailing. If sent by an overnight
courier service, notice shall be deemed given one (1) day after deposit with the
courier service.

      j) Severability. All provisions of this Agreement are severable, and the
unenforceability or invalidity of any of the provisions shall not affect the
validity or enforceability of the remaining provisions. The remaining provisions
will be construed in such a manner as to carry out the full


                                MCI CONFIDENTIAL
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<PAGE>   8
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


intention of the Parties. Section titles or references used in this Agreement
shall not have substantive meaning or content and are not a part of this
Agreement.

      (k) Verio Owned Subsidiaries. MCI will provide location-level billing for
services provided under this Agreement to affiliates specified by Verio,
provided that Verio shall own or control at least twenty-five percent (25%) of
the equity of each specified affiliate. Notwithstanding such location level
billing, Verio shall at all times remain responsible for payment of all charges
incurred by Verio affiliates purchasing services under this Agreement. In the
event that a specified Verio affiliate fails to make payment when due, MCI may
notify Verio and Verio shall make such payment within seven (7) calendar days.

      (1) Entire Agreement. This Agreement, including the Schedules and their
Attachments, constitute the entire agreement between the Parties with respect to
its subject matter and the applicable MCI Tariffs and Tariff Option, and
supersedes all other representations, understandings or agreements which are not
fully expressed herein, whether oral or written offers, no amendment to this
Agreement shall be valid unless in writing and signed by both Parties.

      (m) Signature Authorization. The Parties have duly executed and agreed to
be bound by this Agreement as evidenced by the signatures of their authorized
representatives below. Each Party represents and warrants to the other that the
signatory identified beneath its name below has full authority to execute this
Agreement on its behalf. This offer shall remain open and be capable of being
accepted by Customer until June 16, 1997. Notwithstanding the foregoing, (***)

      (n) Credit Approval. As a condition to MCI's commencement of performance
under this Agreement, Customer shall provide to MCI's reasonable satisfaction
information regarding Customer's current financial status and credit-worthiness
within fourteen (14) calendar days of execution of this Agreement. Within
fourteen (14) business days of receipt thereof, MCI will complete its credit
review and may in its sole discretion request Customer to provide adequate
financial security, assurance of payment, or other payment terms acceptable to
MCI. MCI will base this credit review and any security or payment terms upon an
assumed monthly usage rate (for all MCI services) of (*) (*) the "Credit
Ceiling"). In the event that Verio refuses or otherwise fails to provide such
security, assurance of payment, or to agree to such payment terms within five
(5) business days after receiving MCI's request therefor, MCI may at its option
terminate this Agreement. Neither party shall have any liability to the other in
the event of MCI's termination of this Agreement under this section 11(n)
regardless of reason. This provision, together with paragraphs 11(o) and 11(p)
is intended to supersede any inconsistent provisions of MCI Tariff No. 1,
Section B.7.


                               MCI CONFIDENTIAL
                                       8



<PAGE>   9
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



       (o) MCI may request additional financial security, assurance of payment,
or other payment terms under this Agreement after satisfaction of the condition
in paragraph 11(n) in those situations in which MCI reasonably believes (i)
that Customer's financial circumstances have changed in a material and adverse
manner, provided that Customer shall inform MCI within thirty (30) business days
of its investment in any internet service provider or provider of voice or data
transmission services to whom Customer intends to provide services purchased
under this Agreement. or (ii) MCI reasonably believes that Verio's late payment
history under this Agreement justifies either an increase in the amount of any
financial security provided, or if none has been requested previously, the
provision of such financial security, assurance of payment, or other payment
terms. If Customer fails to provide such security within five (5) business days
of such request it shall be a material breach of this Agreement and MCI at its
sole discretion may notify Customer and immediately terminate provision of
service under this Agreement. The failure of Customer to provide security in
connection with a request under subparagraph (i) of this paragraph (o) shall not
be considered a breach of this Agreement entitling MCI to any termination
payments.

      (p) If Customer's actual usage of MCI services exceeds the Credit Ceiling
set in paragraph 11 (n), then MCI, in its sole discretion, may request that
Customer pay the amount of usage exceeding the Credit Ceiling on an estimated
basis, subject to true-up against Customer's actual usage when billed or lower
its usage to a rate below the Credit Ceiling. For example, if based on MCI's
records of Customer's traffic, MCI estimates a Customer's usage for a month to
be $(*), then MCI may submit to Customer an estimated bill for such usage and
Customer shall either pay $(*) within ten (10) days of receipt MCI's estimated
bill ($(*) less $(*) Credit Ceiling), or, in the alternative, immediately
disconnect circuits or otherwise lower its usage to a level equal to or below
the Credit Ceiling. If Customer elects to pay the amount estimated to exceed the
Credit Ceiling, then when MCI submits its regular invoice covering Customer's
actual usage for that period, it shall credit Customer for amounts already paid
on account, refunding (or crediting against future bills) any overcharge or
billing Customer for any balance due. If Customer elects not to make the
estimated payment requested by MCI or fails to lower its usage to a level equal
to or lower than the Credit Ceiling, then notwithstanding anything in this
Agreement, MCI may terminate this Agreement in whole or in part without prior
notice to Customer or opportunity to cure.

12.  Adjustments.

      (***)


                                MCI CONFIDENTIAL
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<PAGE>   10
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


                                     (***)



                                MCI CONFIDENTIAL
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<PAGE>   11



Any and all prior offers made to Customer, whether written or oral, shall be
superseded by this offer.

MCI TELECOMMUNICATIONS                            VERIO, INCORPORATED
CORPORATION

By: /s/ JERRY A. EDGERTON                         By: /s/ CHRIS DEMARCHE
   -------------------------------                   ---------------------------
Name: Jerry A. Edgerton                           Name: Chris DeMarche
     -----------------------------                     -------------------------
Title:  Vice President                            Title:  CTO
      ----------------------------                      ------------------------

Date: 6/13/97                                     Date: 6/13/97
      ----------------------------                      ------------------------




                                MCI CONFIDENTIAL

                                       11
<PAGE>   12
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



                                   SCHEDULE I
                          SPECIAL CUSTOMER ARRANGEMENT


                                     (***)


                                MCI CONFIDENTIAL
                                       12



<PAGE>   13
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



                                     (***)





                                MCI CONFIDENTIAL
                                       13



<PAGE>   14
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



                           ATTACHMENT A TO SCHEDULE I

   This Attachment A to Schedule I contains the rates, discounts and certain
   other provisions applicable to the Tariffed Services provided to Customer.
   References in this Attachment to standard Tariffed rates and/or discounts
   will include those standard rates and/or discounts in the Price Guide if
   MCI voluntarily or involuntarily as a result of government or judicial
   action cancels in whole or in part any Tariff on file with the FCC.

1. Term and Termination.

   1.1 Term. The term of service of this Attachment will begin on the Attachment
   Effective Date and end upon the completion of sixty (60) months thereafter
   ("Term") or earlier provided the terms and conditions of Section 3.1 of this
   Attachment ("Minimum Volume Commitment") have been fully met. The Attachment
   Effective Date ("Attachment Effective Date") shall be one (1) month from the
   first day of the billing cycle following Customer's signature date.

   1.2 Discontinuation of Business; Bankruptcy. Either Party may terminate this
   Attachment immediately upon notice to the other Party if: (i) such other
   Party dissolves, discontinues or terminates its business operations to which
   the Attachment pertains; (ii) any bankruptcy, reorganization, insolvency,
   dissolution or similar proceeding is instituted by or against such other
   Party, or (iii) such other Party makes any assignment for the benefit of
   creditors.

   1.3 Termination for Cause by Customer. Customer may terminate this Attachment
   for Cause without Termination Liability or liability under Section 3.4 and
   3.5. For purposes of this attachment, Cause shall mean:

           (a) a failure of MCI to perform a material obligation under this
               Attachment which failure is not remedied by MCI within thirty
               (30) days after receipt of written notice; or

           (b) Network Availability for any private line service provided under
               this Attachment falling below (*) for (***) during the Term of
               this Agreement or falls below (*) for any (***) during the term
               of this Agreement. For purposes of this provision, Network
               Availability means the monthly average of the ratio of actual
               service time to scheduled service time. Actual service time is
               defined as the time period during which connectivity is granted.
               Only outages or service degradation caused by the network are
               considered in measuring Network Availability. CPE related
               disruptions, local access, and scheduled maintenance will be
               excluded from Network Availability measurements. Customer's
               termination rights under paragraph(b) are limited to termination
               of the affected circuit, port or route failing to meet
               performance criteria.

   1.4 Termination by MCI. MCI may terminate the Attachment in whole or in part
   immediately upon notice to Customer if any of the following events occur:


                                MCI CONFIDENTIAL
                                       14



<PAGE>   15
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



           (a) A material breach of this Attachment by Customer (i.e., Customer
               fails to meet any payment obligation hereunder and such failure
               is not cured within ten (10) business days after Customer's
               receipt of written notice from MCI notifying Customer of such
               failure); or

           (b) MCI determines in its sole discretion that continued provision of
               any facility, equipment, or service would contravene any local,
               state, national or international regulation, law, or tariff; or

           (c) MCI determines that interruption or termination of a service
               provided by MCI hereunder is necessary to prevent or protect
               against fraud or otherwise protect its personnel, agents,
               facilities, or services; or

           (d) Any third-party subcontractor or vendor to MCI is unable to
               continue to provide such facility, or component of equipment, or
               service for any reason; provided, however, that where such third
               party has ceased to provide any facility, equipment, or service,
               MCI may, at its option, continue to provide to Customer a
               comparable facility, equipment, or service by or through another
               vendor under comparable terms and conditions.

   MCI's termination rights under paragraphs (b), (c) and (d) are limited to
   termination only of the affected services.

   1.5 Termination Liability. If the Customer terminates service under this
   Attachment before the expiration of the Term other than as set forth in
   Schedule I Section 1.3 of this Attachment or to take service under another
   arrangement with MCI having equal or greater term and volume requirements,
   or if MCI terminates this Attachment pursuant to Section 1.4(a), Customer
   will be required to: (i) repay all credits received under this Attachment;
   and, (ii) pay an early termination charge calculated in accordance with
   sections 3.4 and 3.5.

2. Services. Services may consist of any one or more of those telecommunications
   services provided to Customer pursuant to the Tariffs. As such, the services
   are subject to availability as determined by MCI.

3. Minimum Volume Commitments and Underutilization Charges.

   3.1    Minimum Volume Commitment.

   3.1.1  During the Term of this Agreement, Customer shall purchase MCI
   Tariffed Service under this Attachment that equal or exceed (***), calculated
   at Net Rates, as defined below in Section 3.3, (the "Tariffed Services
   Minimum Volume Requirement or "Tariffed Services MVR").

   3.1.2  If Customer satisfies the Tariffed Services MVR prior to the
   completion of the Term, the Agreement shall continue for a supplemental
   period of twelve (12) months ("Supplemental Period") from the date one which
   the Customer has satisfied the Tariffed


                                MCI CONFIDENTIAL
                                       15




<PAGE>   16
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


   Services MVR or until completion of the Term (i.e. 60 months), whichever
   occurs first. During the Supplemental Period, the Customer must satisfy an
   additional annual commitment, calculated at Net Rates, of (***) thereof
   ("Revised Tariffed Services MVR"). In the event less than twelve (12) months
   remains in the service term, then this amount shall be pro-rated over such
   remaining term.

   3.1.3 If the Customer meets or exceeds (***) per month (at Net Rates) of MCI
   Tariffed Services purchased under this Agreement for a period of three (3)
   consecutive months, then the Parties shall to enter into good faith
   negotiations aimed at conforming the rates, term and volume commitment to
   customer's actual usage. Any failure of the Parties to reach a mutually
   acceptable solution with regard to the rates and charges under this
   Attachment shall not affect the requirement for the Customer to satisfy the
   Tariffed Services MVR or any other term and condition of this Agreement.

   3.2 Subminimum Volume Commitment. Notwithstanding anything to the contrary,
   during the Term of this Agreement, Customer shall purchase from MCI Inter
   Office Channel ("IOC") Services in an amount of at least for purchase of
   (***). This IOC commitment is a portion of the commitment referred to in
   section 3.1.1.

   3.3 Net Rates. For purposes of this Attachment, "Net Rates" shall mean
   Customer's monthly billing for MCI Tariffed Services at the rates for which
   the Customer qualifies under this Agreement after application of any
   applicable discounts. "Net Rates" shall be calculated by adding Customer's
   usage charges for MCI Tariffed Services at the rates identified herein (after
   application of any applicable discounts) and monthly recurring and usage
   charges, based upon standard Tariffed rates for any combination of other
   MCI Tariffed Services, including but not limited to, pass-through
   access/egress (or related charges) imposed by third parties, any recurring
   charges imposed in the Tariff, MCI Directory Assistance Charges, MCI
   intrastate usage charges, MCI International Service(s) charges, and charges
   under any Network Pricing Plan specified in the Tariff. Charges for the
   following are excluded from the calculation of Net Rates: goods and services
   that are not tariffed (including MCI Enhanced Services provided under
   Schedule II), MCI charges for MCI operator services for pay phones or hotel
   room phones under the control of Customer, non-recurring charges, and any
   taxes or surcharges applicable to any MCI services.

   3.4 Tariffed Services MVR Underutilization. If after the completion of the
   Term of this Agreement, or early termination thereof by Customer, Customer's
   usage charges, calculated at Net Rates, do not equal or exceed the Tariffed
   Services MVR, Customer will pay, in addition to all accrued but unpaid usage
   charges and other charges, an underutilization charge equal to (***) of the
   difference between (a) the Tariffed Services MVR and (b) Customer's actual
   purchase of MCI services under this agreement during the Term. Customer
   agrees that such charges are reasonable.


                                MCI CONFIDENTIAL
                                       16



<PAGE>   17
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.



   3.5 Subminimum Underutilization. If after the completion of the Term of this
   Agreement, or following early termination of this agreement Customer's
   purchase of MCI-IOC services has not expired or exceeded the Subminimum
   stated in Section 3.2 of this Attachment, Customer will pay, in addition to
   all accrued but unpaid usage charges and other charges, an underutilization
   charge equal to (***) of the difference between the Subminimum and (b)
   Customer's usage charges for the MCI IOC Service. Customer agrees that such
   charges are reasonable.

4. Rates and Discounts for the Services. Unless otherwise noted, the rates and
   discounts provided for in this Attachment are in lieu of, and not in addition
   to, any standard rates, discounts or commissions to which Customer is or
   would otherwise be entitled to receive by application of any MCI Tariff.
   Unless otherwise stated, the rates below will fluctuate with any changes in
   the Tariff.

   4.1 Interstate/Intrastate Voice Service. Rates and charges are per the
   Tariff, except as stated below:

   4.1.1 VNET Domestic

                  -----------------------
                  Ded/Ded     $(*)/minute
                  Ded/Sw      $(*)/minute
                  Sw/Ded      $(*)/minute
                  Sw/Sw       $(*)/minute

  The rates above apply to interstate and intrastate calls and are subject to
  increase or decrease over the life of the Term by the same percentage change
  that occurs to the standard tariff rate.

  4.1.2 MCI 800

                  -----------------------

                  DAL         $(*)/minute
                  CBL         $(*)/minute

  The rates above apply to interstate and intrastate calls and are subject to
  increase or decrease over the life of the Term by the same percentage change
  that occurs to the standard tariff rate.

  4.2 International Voice Service.

                Rates and discounts are per the Tariff.

  4.3 Dedicated Leased Line Service. Rates and charges are per the Tariff,
  except as stated below:

                Inter-Office Channel (IOC)

                The following discounts apply to the following IOC service(s):



                                MCI CONFIDENTIAL
                                       17

<PAGE>   18
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


                            (a)  TDS45 - IOC distance less than or equal to (*)
         miles:_(*) plus (*) per mile_- IOC distance greater than (*) miles: (*)
         off Tariff
                            (b)  TDS 1.5 - (*) off Tariff 1
                            (c)  Fract T1 - (*) off Tariff 1
                            (d)  DDS 56/64 - (*) off Tariff 1
                            (e)  DSO 56/64 - (*) off Tariff 1

4.4      Dedicated Access Services.  Rates and charges are per the Tariff,
except as stated below:

         4.4.1   The following discounts apply to dedicated access for TDS1.5,
DDS, DSO, and Fractional T1 service.

                 (a)   Standard Five (5) Year APP discounts (Currently (*), for
                       T1, and (*) for DDS/DSO)
                 (b)   Monthly Recurring Charges (M.R.C.) for Access 
                       Coordination (A.C.) and Central Office Connection 
                       (C.O.C.) are (*)
                 (c)   Local loop, A.C. and C.O.C installation charges are (*).

         4.4.2   The following discounts apply to dedicated access for MCI
Local Service (where offered by MCI).

                 (a)   Standard Pricing (Currently (*) below MCI's Standard
                       rates)                                 
                 (b)   Standard Five (5) Year APP discounts (Currently 
                       (*), for T1, and (*) for DDS/DSO)               
                 (c)   Monthly Recurring Charges (M.R.C.) for Access   
                       Coordination (A.C.) and Central Office          
                       Connection (C.O.C.) are (*).                 
                 (d)   Loop, A.C. and C.O.C. installation charges are (*).
                                                                       
Customer agrees that within sixty (60) days of notice from MCI that MCI
dedicated access for Local Service(s) (as described in Section 4.4.2 above) is
available to Customer's facility, it will to (***). The rates and charges for
MCI Local Service(s) are listed above.

For access into each MCI Points of Presence ("MCI PoP"), the Customer hereby
grants to MCI (at MCI's discretion) the option for MCI to either (***).  In the
case where access is provided (***), the Customer shall be charged and hereby
agrees to pay the following Monthly Recurring Charges (M.R.C.) for (*) connect:

<TABLE>
<CAPTION>
         Monthly (*) Connect Charges
               <S>         <C>    
               TDS-45      $(*)
               DS- 1       $(*)
               DS-O/DDS    $(*)
</TABLE>                 

         4.4.3 Forced Local Loop Services





                                MCI CONFIDENTIAL
                                       18
<PAGE>   19
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


         The following discounts apply when MCI (***), other than the POP
         normally used in that location, in an effort to (***).

                          (a)     Standard Five(5) Year APP discounts
                                  (Currently (*), for T1, and (*) for DDS/DSO).

                          (b)     Monthly Recurring Charges (M.R.C.) for Access
                                  Coordination (A.C.) and Central Office
                                  Connection (C.O.C.) are (***).

                          (c)     Local loop, A.C. and C.O.C. installation
                                  charges (***).

                 4.4.4    Dedicated access for TDS45 will be subject to its
         availability and will be quoted to Customer on an individual case
         basis.

                 4.5      Frame Relay Service.  Rates and charges are per
         the Tariff, except as stated below:

                 The standard tariff rates apply for Frame Relay service and
         the standard 5 Year Term Discount on Port and PVC Charges (listed
         below) apply as well.  The rates and charges for Frame Relay shall
         fluctuate with the Tariff.

<TABLE>
<CAPTION>
                 Current Discount Table:                             
                 -----------------------                             
                 Gross Monthly Revenue                       Discount
                 <S>                                          <C>    
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
                 $  (*)                                        (*)
</TABLE>

                 4.6      Charges Not Eligible For Discount.  The rates and
         discounts set forth in this Section 4 do not apply to the following:
         charges for MCI Services other than those described in Section 4;
         non-Tariffed products; access or egress (or related) charges imposed
         by third parties; standard Tariffed recurring charges; standard
         Tariffed non-recurring charges and taxes or tax-like surcharges.

5.       Tariffed Rates.  If MCI offers, pursuant to a Tariff, discounts for
         combination(s) of Services (as opposed to discounts on a particular
         Service) and Customer has subscribed to such Services, than Customer
         may elect to receive the benefits of such discounts in lieu of the
         discounts set forth in Section 4 of this Attachment.  If Customer
         makes such an election, the new discounts will control for the
         remainder of the Term.


                                MCI CONFIDENTIAL
                                       19
<PAGE>   20
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.


6.       Qualifying Conditions.  The Customer must satisfy the following
         conditions by the Effective Date of the Agreement between the Customer
         and MCI:

                 6.1      Customer must qualify, as of the date of execution of
                          this Agreement, (***).

                 6.2      Customer must be (***).

         Customer understands that MCI, in conducting its business in the
         manner set forth herein, is subject to the Communications Act of 1934,
         as amended or succeeded, and as interpreted and applied by the
         FCC.  The Master Agreement, Schedule I, and this Attachment A,
         together with the appropriate MCI tariffs is the complete agreement of
         the parties with respect to Tariffed Services and supersedes all other
         prior agreements and representation concerning its subject matter.





                                MCI CONFIDENTIAL
                                       20
<PAGE>   21
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

                                  SCHEDULE II
                          ENHANCED SERVICES AGREEMENT

         Customer's use of MCI Enhanced Services and any additional products in
         the Attachments to Schedule II will not receive the rates provided
         under Schedule I and its Attachments nor will such usage be included
         in determining the discounts or credits provided under Schedule I of
         the Agreement.

1.       Term and Termination

                 1.1      Term.  The Term of this Schedule II shall begin on
                          the Schedule Effective Date and end upon the
                          completion of sixty (60) months thereafter ("Term").
                          The Schedule Effective Date ("Schedule Effective
                          Date") will begin one (1) month from the first day of
                          the billing cycle following Customer's signature
                          date.

                 1.2      Discontinuation of Business; Bankruptcy.  Either
                          Party may terminate this Schedule immediately upon
                          notice to the other Party if: (i) such other Party
                          dissolves, discontinues or terminates its business
                          operations to which the Agreement pertains; (ii) any
                          bankruptcy, reorganization, insolvency, dissolution
                          or similar proceeding is instituted by or against
                          such other Party; or (iii) such other Party makes any
                          assignment for the benefit of creditors.

                 1.3      Termination for Cause by Customer.  Customer may
                          terminate this Schedule for Cause without Termination
                          Liability or liability under Sections 1.5 or 2. For
                          purposes of this Attachment, Cause shall mean:

                          (a)     a failure of MCI to perform a material
                          obligation under this Attachment which failure is not
                          remedied by MCI within thirty (3O) days after receipt
                          of written notice; or

                          (b)      Network Availability for SMDS service
                          provided under this Attachment falls below (*)% for
                          six (6) consecutive months during the Term of this
                          Agreement.  For purposes of this provision, Network
                          Availability means the monthly average of the ratio
                          of actual service time to scheduled service time.
                          Actual service time is defined as the time period
                          during which connectivity is granted.  Only outages
                          or service degradation caused by the network are
                          considered in measuring Network Availability.  CPE
                          related disruptions, local access, and scheduled
                          maintenance will be excluded from Network
                          Availability measurements.

                          (c)      At this time there is no Service Level
                          Agreement for MCI Hyperstream ATM service.  If at any
                          time during the term of this Agreement, MCI
                          implements a generally available Service Level
                          Agreement for MCI Hyperstream ATM service, then the
                          parties will amend this Agreement to include the
                          terms and conditions of such generally available
                          Service Level Agreement including any applicable
                          change in rates.





                                MCI CONFIDENTIAL
                                       21
<PAGE>   22
         Customer's termination rights under paragraphs (b) and (c) are limited
         to termination only of the affected services.

1.40     Termination by MCI.  MCI may terminate the Schedule immediately upon
         notice to Customer if any of the following events occur:

         (a)     A material breach of this Schedule by Customer (i.e., Customer
         fails to meet any payment obligation hereunder and such failure is not
         cured within ten (10) business days after Customer's receipt of
         written notice from MCI notifying Customer of such failure); or

         (b)     MCI determines in its sole discretion that continued provision
         of any facility, equipment, or service would contravene any local,
         state, national or international regulation, law, or tariff; or

         (c)      MCI determines that interruption or termination of a service
         provided by MCI hereunder is necessary to prevent or protect against
         fraud or otherwise protect its personnel, agents, facilities, or
         services; or

         (d)     Any third-party subcontractor or vendor to MCI is unable to
         continue to provide such facility, or component of equipment, or
         service for any reason; provided, however, that where such third party
         has ceased to provide any facility, equipment, or service, MCI may, at
         its option, continue to provide to Customer a comparable facility,
         equipment, or service by or through another vendor under comparable
         terms and conditions.

         MCI's termination rights under paragraphs (b), (c) and (d) are limited
         to termination of the affected services.

1.5      Termination Liability.  If the Customer terminates service under this
         Schedule before the expiration of the Term other than as set forth in
         Section 1.3, or to take service under another arrangement with MCI
         having equal or greater term and volume requirements, or if MCI
         terminates this Schedule pursuant to Section 1.4(a), Customer will be
         required to: (i) repay all credits received under this Schedule; and,
         (ii) pay an early termination charge as calculated in Section 2.1 of
         this Attachment for each monthly billing period remaining in the Term
         or a pro rata portion thereof for any partial monthly billing period.
         The Customer, however, will not be liable for termination charges if
         the MCI Hyperstream ATM and/or MCI Hyperstream SMDS services are
         converted to other MCI services of equal or greater value.





                                MCI CONFIDENTIAL
                                       22
<PAGE>   23
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

2.       Minimum Volume Requirements and Underutilization Charges.

         2.1     Minimum Volume Requirement.  During the Term of this Agreement,
         Customer's Net Usage of MCI services purchased under this Schedule II
         shall equal or exceed (*) Dollars ($(*)) (the "ESA MVR").  For purposes
         of this Schedule II, "Net Usage" means recurring and usage charges
         accruing to Customer's account, after application of all discounts and
         credits, during each monthly billing period, including without
         limitation charges for usage of all Enhanced Services provided by MCI
         under this Schedule (as may be supplemented from time-to-time with the
         addition of other enhanced services provided to Customer by MCI under
         mutually agreed upon terms and conditions) and excluding without
         limitation access charges, access coordination charges, network
         management charges, all charges expressly excluded in the ESA
         Attachments, CPE, all charges for Tariffed Services, and all taxes and
         surcharges.

         2.2     ESA MVR Underutilization Charge.  If Customer does not satisfy
         the ESA MVR over the Term, then Customer will pay to MCI (i) Customer's
         actual combined monthly recurring and usage charges for MCI Enhanced
         Service, plus (ii) an underutilization charge (which Customer agrees is
         reasonable) equal to (*) percent ((*)%) of the difference between the
         applicable ESA MVR and Customer's actual Net Usage over the life of the
         Agreement.  The Customer, however, will not be liable for
         underutilization charges if the MCI Hyperstream ATM and/or MCI
         Hyperstream SMDS services are converted to other MCI services equal to
         or greater than the difference between the ESA MVR and the actual net
         ESA usage for the month in question.

3.       Provision of ESA Services.

         3.1     MCI shall provide the following MCI Enhanced Services to
         Customer under this Schedule:

                          MCI Hyperstream ATM
                          MCI Hyperstream SMDS

         3.2     ESA Attachments.  Each MCI Enhanced Service provided under
         this Schedule shall have a corresponding ESA Attachment specifying the
         applicable rates, discounts, and other terms and conditions on which
         MCI will provide such MCI Enhanced Service.  To the extent that the
         terms and conditions of any ESA Attachment are inconsistent with the
         terms and conditions of the Master Agreement and this Schedule, the
         ESA Attachment shall govern with respect to the corresponding MCI
         Enhanced Service.

         3.3     Effect of Tariffing.  If, at any time during the Term, MCI
         tariffs any of the MCI Enhanced Services provided pursuant to the
         Master Agreement and this Schedule (each a "Newly Tariffed Service"),
         Customer agrees to promptly execute appropriate additional agreements
         and amendments to the Master Agreement and its corresponding Schedules
         and Attachments the effect of which shall be to eliminate the Newly
         Tariffed Service from the MCI Enhanced Services portion of the Master
         Agreement and to incorporate such Newly Tariffed Service into that
         portion of the Master Agreement (or a separate agreement) which
         governs MCI Tariffed Services.  Such MCI Tariffed Services agreement
         shall contain the same rates, charges, discounts, term commitment, and





                                MCI CONFIDENTIAL
                                       23
<PAGE>   24

         volume commitment for the Newly Tariffed Service as set forth in that
         portion of this Schedule which governs MCI Enhanced Services.
         Customer acknowledges and agrees that MCI shall have no obligation to
         include any equipment provided under the Master Agreement and this
         Schedule or any charges payable for such equipment in any such
         agreement for tariffed services.  In the event that a Newly Tariffed
         Service is eliminated from this Schedule, the ESA and SCA MVRs will be
         adjusted accordingly.

4.       Warranty.  MCI's warranty obligations, if any, with respect to each
         MCI Enhanced Service are set forth in the applicable Attachment.
         EXCEPT AS SPECIFICALLY SET FORTH IN THE MASTER AGREEMENT, THIS
         SCHEDULE AND THE ATTACHMENTS, MCI MAKES NO WARRANTIES, EXPRESS OR
         IMPLIED, AS TO ANY MCI ENHANCED SERVICES.  MCI SPECIFICALLY DISCLAIMS
         ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT
         LIMITATION ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
         PARTICULAR PURPOSE AND ANY INTELLECTUAL PROPERTY WARRANTIES Of ANY
         TYPE.

5.       Limitation of Liability.  NOTWITHSTANDING THE FOREGOING, MCI'S TOTAL
         LIABILITY TO CUSTOMER ARISING FROM THIS SCHEDULE AND THE ATTACHMENTS
         SHALL BE LIMITED TO THE LESSER OF (A) CUSTOMER'S PROVEN DIRECT DAMAGES
         OR (B) THE TOTAL AMOUNT PAID BY CUSTOMER TO MCI FOR THE SPECIFIC
         ENHANCED SERVICE UPON WHICH THE CAUSE OF ACTION IS BASED DURING THE
         ONE (1) MONTH PERIOD PRIOR TO THE EVENT GIVING RISE TO THE CAUSE OF
         ACTION.  THE FOREGOING LIMITATION APPLIES TO ALL CAUSES OF ACTIONS AND
         CLAIMS, INCLUDING WITHOUT LIMITATION BREACH OF CONTRACT, BREACH OF
         WARRANTY, NEGLIGENCE, STRICT LIABILITY, MISREPRESENTATION AND OTHER
         TORTS.  FURTHER, NO CAUSE OF ACTION WHICH AROSE MORE THAN ONE (1) YEAR
         PRIOR TO THE INSTITUTION OF A LEGAL PROCEEDING ALLEGING SUCH CAUSE OF
         ACTION MAY BE ASSERTED BY EITHER PARTY AGAINST THE OTHER.





                                MCI CONFIDENTIAL
                                       24
<PAGE>   25
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

                         ESA SCHEDULE ATTACHMENT NO. 2
                          MCI HyperStream ATM Service

A.       Description: MCI HyperStream Asynchronous Transfer Mode (ATM) is a
connection oriented public/private network data service.  HyperStream ATM is a
cell-based broadband technology which allows seamless high speed wide area and
local area network connections.  A wide range of data applications connect with
HyperStream ATM including local area network (LAN) interconnections, high-speed
transmission of digitized medical imaging across the country and desktop
videoconferencing enabling users to share multimedia applications.

B.      Rates & Charges

MCI's HyperStream ATM Service provides the most up to date pricing options in
the industry.  The HyperStream ATM Service rate structure enables customers to
tailor their ATM service to meet changing business needs and compliments the
flexible nature of Asynchronous Transfer Mode service.

The HyperStream ATM Service rate structure has three components: Access, Port,
and Usage charges.

(1)      Access:

Local loop and access coordination charges are based on standard tariff rates.
In the case of DS-3 and below the IOC and COC or backhaul portion of the
circuit charge is included in the ATM port charge.  In the case of OC-3, the
backhaul portion is NOT included in the ATM port charge.  For OC-3 ATM access,
the customer pays for an OC-3 facility from their location to the closest ATM
node site.

(2)      Ports:

Port charges are based upon the selected bandwidth needed to connect to the
HyperStream ATM network.  MCI currently offers DS-1, DS-3 and OC-3 ATM UNI
ports.

(3)      Usage:

Usage charges are based upon the Service Class and associated traffic contract
parameters selected by the customer and are described as Fixed SCR charges
similar to Frame Relay "Fixed CIR PVC Rates".

Port Charges:

<TABLE>
         <S>          <C>         <C>
         ATM UNI      DS-1        $ (*)  per month per port
         ATM UNI      DS-3        $ (*)  per month per port
</TABLE>





                                MCI CONFIDENTIAL
                                       25
<PAGE>   26
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

<TABLE>
         <S>                      <C>
         ATM UNI      OC-3        $(*) per month per port

         Port Reconfiguration Charge          $(*)
         Port Installation Charge             $(*)
</TABLE>

Non Recurring PVC Charges:

<TABLE>
<S>                                        <C>
PVC Installation Charge                    $(*) 
PVC Reconfiguration Charge                 $(*)*
</TABLE>

* Applied every time the parameters of a VC within a VP are changed as well as
VP parameter changes.

ATM UNI SERVICE CLASSES: Variable Bit Rate - Non Real Time

<TABLE>
<CAPTION>
PCR             kbps        Fixed SCR
<S>           <C>              <C>
PCR=1.544         16           $(***)
PCR=1.544         32           $(***)
PCR=1.544         48           $(***)
PCR=1.544         64           $(***)
PCR=1.544        128           $(***)
PCR=1.544        192           $(***)
PCR=1.544        256           $(***)
PCR=1.544        320           $(***)
PCR=1.544        384           $(***)
PCR=1.544        448           $(***)
PCR=1.544        512           $(***)
PCR=1.544        576           $(***)
PCR=1.544        640           $(***)
PCR=1.544        704           $(***)
PCR=1.544        768           $(***)
PCR=1.544        832           $(***)
PCR=1.544        896           $(***)
PCR=1.544        960           $(***)
PCR=1.544      1,024           $(***)
PCR=1.544      1,088           $(***)
PCR=1.544      1,170           $(***)
PCR=1.544      1,216           $(***)
PCR=1.544      1,280           $(***)
PCR=1.544      1,344           $(***)
PCR=45         1,536           $(***)
PCR=45         4,608           $(***)
PCR=45        10,800           $(***)
</TABLE>                   
                           




                                MCI CONFIDENTIAL
                                       26
<PAGE>   27
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

<TABLE>
<S>         <C>           <C>
PCR=45       16,000       $(***)
PCR=45       25,000       $(***)
PCR=45       35,800       $(***)
PCR=155     101,900       $(***)
PCR=155     131,776       $(***)
</TABLE>


ATM UNI SERVICE CLASS: Constant Bit Rate

<TABLE>
<CAPTION>
Kbps              Fixed PCR/SCR
                            CBR
<S>               <C>
16                        (***)
32                        (***)
48                        (***)
64                       $(***)
128                      $(***)
192                      $(***)
256                      $(***)
320                      $(***)
384                      $(***)

Kbps                  Fixed PCR/SCR

448                      $(***)
512                      $(***)
576                      $(***)
640                      $(***)
704                      $(***)
768                      $(***)
832                      $(***)
896                      $(***)
960                      $(***)
1,024                    $(***)
1,088                    $(***)
1,170                    $(***)
1,216                    $(***)
1,280                    $(***)
1,344                    $(***)
1,536                    $(***)
4,608                    $(***)
10,800                   $(***)
16,000                   $(***)
25,000                   $(***)
35,800                   $(***)
101,900                  $(***)
131,776                  $(***)
</TABLE>





                                MCI CONFIDENTIAL
                                       27
<PAGE>   28
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

Note: All PVC rates are simplex.  Asymmetrical PVC's are allowed.

Discount: The Customer shall receive a (*) percent (*%) discount off of the
above listed Port and PVC charges.  (*)





                                MCI CONFIDENTIAL
                                       28
<PAGE>   29
                     ENHANCED SCHEDULE ATTACHMENT NO.  I
                     SWITCHED MULTIMEGABIT DATA SERVICE


A.     MCI ENHANCED SERVICE:

       Name: Switched Multimegabit Data Service (SMDS)

       Description: SMDS is available in the United States as a connectionless
packet-oriented data transport service, provided by MCI Telecommunications
Corporation ("MCIT").  At the originating customer premises the customer's
equipment places the data into packets and gives each packet an E.164 source
and destination customer address.  Subject to certain restrictions, MCIT
routes the packets over the MCIT Network to the terminating E.164 address.
For purposes of this Agreement, the MCIT Network shall mean the integrated data
network  system owned and operated by MCIT (which may be connected to services
provided by third parties) for general use by its customers to transmit and
receive data.  SMDS is available at speeds up to 34Mbps.

       Technical Description: SMDS operates at layers two and three of the OSI
model and is designed to conform to the IEEE 802.6 Metropolitan Area Networking
Standard and to the Bellcore Technical Reference TR-TSV-000772.

       A.     Access to SMDS: You shall obtain access to SMDS via dedicated
digital facilities (DXI-SMDS) or Local Exchange Carrier Interconnection
(XA-SMDS), only.

       B.     Availability: SMDS is available between cities listed in MCIT
Tariff FCC No. 1, Section C.12, Table IV, Part A, as amended from time to
time, or any successor tariff (the "Tariff ").


B.     RATES AND CHARGES

       HyperStream SMDS pricing is composed of three primary parts: (1) Access
charges , (2) Port charges, (3) Usage charges

(1)    ACCESS CHARGES

Access charges are the charges the customer pays for access from the customer
location to the MCI POP.

(2)    PORT CHARGES

Port charges are based upon the customers selected mode of connection (DXI or
XA) and applicable connection speeds (56kbps to 34Mbps).





                                MCI CONFIDENTIAL
                                       29
<PAGE>   30
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

Port charges are based on the access method chosen to connect to the
HyperStream SMDS Network.  The HyperStream SMDS Service provides two types:
XA-SMDS (eXchange Access) and DXI-SMDS (Data eXchange Interface).  The access
rate includes backhaul from the MCI POP closest to the customers location to
the closest HyperStream SMDS gateway.

DXI-SMDS is the method used to gain direct access to HyperStream SMDS.  The
customer connects directly to MCI's HyperStream SMDS Network.  Monthly port and
usage charges for DXI-SMDS service are outlined below.

XA-SMDS is the method used to gain access to MCI's HyperStream SMDS via LEC
provided SMDS services.  Customers connecting to a local LEC to obtain SMDS
access will be billed by the LEC for LEC-provided services and billed by MCI
for the IXC portion of the network.  MCI charges are outlined below.

(3)    USAGE CHARGES

DXI-SMDS customers connecting directly to MCI's SMDS network are charged for
usage based on megabytes delivered.  These charges are based on Sustained
Information Rate (SIR) and are included in assessing all minimum and maximum
usage charges.

XA-SMDS customers using LEC access to get on to the HyperStream SMDS Network
and/or terminate traffic to a LEC-connected location are charged for access and
egress to/from the MCI HyperStream SMDS network as well as transport across the
network (access + transport + egress) based on the number megabytes delivered.
These charges are based on Sustained Information Rate (SIR) and are included in
assessing all minimums and maximums.

All DXI and XA usage charges can be combined to count towards satisfaction of
usage minimums and maximums.  Port, access, and fee charges do not count
towards satisfaction of usage minimums and maximums.



DXI Port Charges (direct connection to MCI's HyperStream Network)

<TABLE>
<CAPTION>
Speeds                          Monthly Charge              Installation
Available
<S>                               <C>                         <C>
56/64 K                           $(***)                      $(***)
112/128                           $(***)                      $(***)
224/256                           $(***)                      $(***)
336/384K                          $(***)                      $(***)
448/512K                          $(***)                      $(***)
672/768K                          $(***)                      $(***)
896/1024 K                        $(***)                      $(***)
</TABLE>





                                MCI CONFIDENTIAL
                                       30
<PAGE>   31
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

<TABLE>
<S>                             <C>                   <C>
1344/1536 K                     $(***)                $(***)      
4.5Mbps                         $(***)                $(***)      
10.5Mbps                        $(***)                $(***)      
</TABLE>

DXI Usage Charges:

(per megabyte, end to end transport)

This is the charge for transporting the customers traffic across the MCI SMDS
network and is based on megabytes delivered.

<TABLE>
<S>                    <C>
<=T-1                    >T-1
$(*)                   $(*)
</TABLE>


DXI-Usage Minimums and Maximums

<TABLE>
<CAPTION>
Speed                               Minimum             Maximum
<S>                                 <C>                  <C>
56/64K                              $(*)                 $(*)
112/128 K                           $(*)                 $(*)

<CAPTION>
Speed                               Minimum             Maximum
<S>                                 <C>                  <C>

224/256 K                           $(*)                 $(*)
336/384 K                           $(*)                 $(*)
448/512 K                           $(*)                 $(*)
672/768 K                           $(*)                 $(*)
896/1024                            $(*)                 $(*)
1344/1536 K                         $(*)                 $(*)
4.5Mbps (Class 1)                   $(*)                 $(*)
10.5Mbps (Class 2)                  $(*)                 $(*)
</TABLE>



XA-SMDS Port (connection to MCI's HyperStream Network via a LEC)

<TABLE>
<CAPTION>
Speeds             Monthly           Installation
Available
<S>              <C>                 <C>
DS-0             $(*)              $(*)
DS-1             $(*)              $(*)
4Mbps            $(*)              $(*)
10Mbps           $(*)              $(*)
16Mbps           $(*)              $(*)
25Mmbps          $(*)              $(*)
</TABLE>





                                MCI CONFIDENTIAL
                                       31
<PAGE>   32
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

XA Usage Charge
(per megabyte)

<TABLE>
<CAPTION>
Access*              Egress*
<S>                  <C>
$(*)                 $(*)
</TABLE>

Note: XA access and/or egress rates are combined with the DXI (or transport)
rate if the customer is sending traffic to or from an XA port to a DXI port.
Access and egress are charged if the customer is sending traffic to and from
XA ports.

XA-SMDS Usage Minimums and Maximums (based on SIR)

<TABLE>
<CAPTION>
Speed      Minimum         Maximum
<S>        <C>             <C>
DS-0       $(*)             $(*)
DS-1       $(*)             $(*)
4M         $(*)             $(*)
10m        $(*)             $(*)
16M        $(*)             $(*)
25M        $(*)             $(*)
</TABLE>

The Customer shall receive a (*) percent ((*)%) discount off of the above
port and usage charges for SMDS.  In addition, (*)

--------------------------------------------------------------------------------

FEES:

HyperStream SMDS offers additional features which have fees associated with
them.


Closed User Groups:

MCI's HyperStream SMDS Service offers customers the option to create closed
user groups (CUG).  MCI can create Individual address screening tables which
can be used to define where traffic can be sent to and from which addresses
traffic can be received.  These addresses can be within the customers
organization or other organizations the customer wishes to communicate with on
an authorized basis.  Closed User Groups can also be used to segregate traffic
based on protocol type.  For example, IPX users could be collected into one or
more Closed User Groups.

<TABLE>
<S>                                   <C>
Address Screening (monthly)            $(*)
Address Screening (install)            $(*)
</TABLE>






                                MCI CONFIDENTIAL
                                       32
<PAGE>   33
THE INFORMATION BELOW MARKED (*) OR (***) HAS BEEN OMITTED PURSUANT TO A
REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED PORTIONS HAVE BEEN SEPARATELY
FILED WITH THE COMMISSION.

Multicasting:

MCI's HyperStream SMDS Service offers the customer the ability to multicast -
broadcast a single message to multiple recipients.  This capability is unique
to SMDS technology.  The customer creates a single packet and that packet is
replicated across the network by MCI to sites defined by the customer in a
closed user group.

<TABLE>
<S>                               <C>
Group Address (monthly)            $(*)
Group Address (install)            $(*)
</TABLE>





                                MCI CONFIDENTIAL
                                       33