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                       MCI WORLDCOM NETWORK SERVICES, INC.

                      CLASSIC/TRANSCEND-TM- SWITCHED SERVICES

                                 AMENDMENT NO. 3

         This Amendment No. 3 is made as of the 15th day of November, 1999,
by and between Logix Communications Corporation ("CUSTOMER") and MCI WorldCom
Network Services, Inc. (successor-in-interest to WorldCom Network Services,
Inc.), a Delaware corporation ("MCI WORLDCOM") to that certain
CLASSIC/TRANSCEND-TM- Telecommunications Services Agreement (the "TSA") dated
December 1, 1998, by and between Customer and MCI WorldCom, including those
certain Program Enrollment Terms (the "PET") and that certain Amendment No. 1
dated November 30, 1998, and that certain Amendment No. 2 dated September 20,
1999 (collectively, the AGREEMENT").  In the event of any conflict between
the terms of the TSA, the PET, Amendment No. 1 or Amendment No. 2 and the
terms of this Amendment No. 3, the terms of this Amendment No. 3 shall
control. The TSA along with the PET, Amendment No. 1, Amendment No. 2 and
this Amendment No. 3 shall collectively be referred to as the "AGREEMENT".
Further, all references to "WorldCom" in the Agreement will be deemed to
refer to MCI WorldCom".

1.       CUSTOMER'S MINIMUM REVENUE COMMITMENT. Effective as of January 1, 2000,
         the parties agree to substitute Subsection 2(A) and Subsection 2(B) of
         the PET to read in its entirety as follows:

         (A) Commencing with the January, 2000 billing period (i.e., February,
         2000 invoice) and continuing through the end of the Service Term
         (including any extensions thereto) (the "COMMITMENT PERIOD"), Customer
         agrees to maintain, on a take-or-pay basis, Monthly Revenue (as defined
         in the applicable Rate and Discount Schedule) of at least $400,000
         ("CUSTOMER'S MINIMUM REVENUE COMMITMENT").

         (B) Notwithstanding anything to the contrary contained in this
         Agreement, as soon as Customer's cumulative Monthly Revenue from
         WorldCom under the terms of this Agreement are equal to at least
         $33,400,000 ("CUSTOMER'S TOTAL COMMITMENT"), Customer may elect to
         terminate Customer's Minimum Revenue Commitment described in Subsection
         2(A) above by providing WorldCom written notice ("CUSTOMER NOTICE"). In
         such event, commencing with the first day of the first full month
         following at least thirty (30) days after WorldCom receives the
         Customer Notice, Customer's Minimum Revenue Commitment shall terminate
         and will no longer be in force or effect. Provided, the applicable
         Discounts set forth in the Rate and Discount Schedule will continue to
         be applicable through the remainder of the Service Term.

2.       OTHER TERMS AND CONDITIONS. Except as specifically amended or modified
         herein, the terms and conditions of the Agreement will remain in full
         force and effect throughout the applicable Service Terms and any
         extensions thereof.


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         IN WITNESS WHEREOF the parties have entered into this Amendment No. 3
as of the date first written above.

LOGIX COMMUNICATIONS CORPORATION           MCI WORLDCOM NETWORK SERVICES, INC.

By: /s/ Albert H. Pharis, Jr.              By: /s/ James Foran
   ------------------------------             --------------------------------
Print Name: Albert H. Pharis, Jr.          Print Name: /s/ James Foran
           ----------------------                     ------------------------
Title: CEO                                 Title: Regional Sales Director
      ---------------------------                -----------------------------


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                                CONFIDENTIAL