Considering TFS Proxy Server? If yes, check the licensing.
The Team Foundation Server (TFS) licensing whitepaper on http://www.microsoft.com/downloads/details.aspx?familyid=1FA86E00-F0A3-4290-9DA9-6E0378A3A3C5&displaylang=en defines the licensing for the various bits and pieces of TFS and is a worthwile read. Note that TFS Proxy requires a full license is licensed on per-device basis.