COLLABORATION AGREEMENT

EXHIBIT 10.24





February 18, 1998







Ulysses G. Auger, II President CAIS, Inc. 1232 22nd St. N.W. Washington, D.C.n 20037



Re: Microsoft/CAIS collaboration on IPORT market trials



Dear Ulysses:



This letter of agreement ("LOA") will confirm the agreement and understanding of CAIS, Inc.("CAIS") and Microsoft Corporation ("Microsoft") (collectively, the "Parties", and singly, a "Party"), with respect to their collaboration (the "Relationship") in sponsoring the beta trials of Atcom, Inc.'s ("Atcom") high speed internet access project, commonly referred to as IPORT (the "Market Trials"). The Parties acknowledge that each is working with Atcom, under separate contractual arrangements, with respect to certain other elements of the Market Trials.



In addition to the Parties' independent commitments to collaborate with Atcom regarding the Market Trials through their respective technological and implementational commitments, Microsoft and CAIS each shall contribute the following additional resources in an effort to successfully implement the Market Trials.



A. Microsoft's Role. Microsoft's role in the Relationship includes the following:



1. Microsoft has made a significant financial contribution toward the

overall project costs of implementing the Market Trials.



2. Microsoft has agreed to work with Atcom to license certain software

and other intellectual property rights to Atcom for use in connection

with the Market Trials. Microsoft and Atcom are separately negotiating

such license and other terms.



3. Microsoft has agreed to contribute significant marketing and

promotional services as an in-kind contribution toward the

implementation of the Mar ...