A. BranchCache is a new feature of Windows 7 that allows clients at a remote location to maximize bandwidth efficiency. Information one client at a location downloads from a central server can be shared between all clients at the location. This sharing can be done in a distributed fashion, where each client has its own cache for information it has downloaded and shares with its peers. Or you can use a hosted model, where a dedicated BranchCache server is located at each location, and clients forward downloaded content to it for centralized caching then directly request from this server instead of performing a broadcast requesting information.
SCCM also supports distributed environments by providing distribution point capabilities and branch distribution points for smaller locations, allowing a PC to act as the software access point. However, it still has some SCCM-configured components. SCCM 2007 R2 supports BranchCache, and once it's enabled, one client at a location can download something from SCCM then share it to all clients at the same location. This way it avoids multiple calls over the WAN for the same information.
To allow SCCM to use BranchCache you need to make sure your distribution points are running Windows Server 2008 R2 with the BranchCache feature installed. Also, BITS must be enabled. (It's configured in the properties of the distribution point, as shown here.)
Ensure your advertisements are configured to use "download and execute" by selecting the Download content from distribution point and run locally option in the Distribution Points tab of the advertisement for both the LAN and slow networks.
The normal client-side BranchCache configuration must be completed. Clients will then use BranchCache for SCCM traffic.