How BranchCache Works

Depending on how you implement it, BranchCache can function in one of two modes:

• Hosted Cache This scenario uses a client/server architecture in which clients running Windows 7 at a branch office site cache the content they've downloaded over the WAN from the central office to a Windows Server 2008 R2 computer (called the Hosted Cache) located at the same branch office site. Other clients that need this content can then retrieve it directly from the Hosted Cache without needing to use the WAN link.
  Hosted Cache mode does not require a dedicated server. The BranchCache feature can be enabled on a server that is running Windows Server 2008 R2, which is located in a branch that is also running other workloads. In addition, BranchCache can be set up as a virtual workload and can run on a server with other workloads, such as File and Print.
• Distributed Cache This scenario uses a peer-to-peer architecture in which Windows 7 clients cache content that they retrieve by using the WAN, and then they send that content directly to other authorized Windows 7 clients on request.
  Distributed Cache mode allows IT professionals to take advantage of BranchCache with minimal hardware deployments in the branch office. However, if the branch has deployed other infrastructure (for example, servers running workloads such as File or Print), using Hosted Cache mode may be beneficial for the following reasons:
  • Increased cache availability Hosted Cache mode increases the cache efficiency, because content is available even if the client that originally requested the data is offline.
  • Caching for the entire branch office Distributed Cache mode operates on a single subnet. If a branch office that is using Distributed Cache mode has multiple subnets, a client on each subnet needs to download a separate copy of each requested file. With Hosted Cache mode, all clients in a branch office can access a single cache, even if they are on different subnets.