Driven by challenges of reducing cost and complexity of branch offices, results in organizations consolidating and centralizing servers and their applications.
However, centralizing increases the dependency on the availability and quality of the WAN link. A direct result of centralization is the increased utilization of the WAN link and the degradation of application performance.
Windows Server 2008 R2 introduces a feature called BranchCache.
The BranchCache feature in Windows Server 2008 R2 and Windows 7 Client helps increase network responsiveness of applications and reduces the network utilization on WAN links that connect branch offices, improving end user experience at branch locations, by locally caching frequently used content on the branch office network.
When accessing content stored on Windows Server 2008 R2, users in a branch office don't need to wait as long to download files from headquarters. When BranchCache is enabled (on a share basis), a copy of the data accessed from an intranet web site (via http/https) or a file server (via SMB) is cached locally within the branch office. When another user on the same network requests the same file, the user gets access to the content almost immediately as it is downloaded from the local cache rather than over a limited bandwidth connection back to headquarters.
BranchCache caches both HTTP and SMB content and ensures access to only authorized users as the authorization process is carried out at the servers located in the data center. BranchCache only serves content to users who have the right permissions and always checks to make sure it is delivering the latest version of the file. BranchCache works alongside SSL or IPSEC encrypted content and accelerates delivery of such content as well.
So what does this mean in the end?? What applications are BranchCache candidates? Everything running content over SMB or HTTP(s), like File Servers, SharePoint sites, Web Applications, WSUS servers, …
BranchCache can operate in two modes:
1. Hosted Cache mode: a server in the branch running Windows Server 2008 R2 hosting the cached files.
2. Distributed (Cooperative) Cache: a branch server is not required, as copies of files are directly cached on Windows 7 clients/peers in the branch and sent to other Windows 7 clients/peers as needed. The data cached in cache pool of Windows 7 clients.
|Hosted Cache mode ||Distributed Cache (P2P Cache) |
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BranchCache is a passive cache, it decreases bandwidth utilization between headquarters and the branch when the user requests files.
BranchCache only caches read requests, so it will never interfere with a user saving a file.
- File server: requires Windows Server 2008 R2 with BranchCache Feature installed (use ServerManager).
- Web server: requires Windows Server 2008 R2 with BranchCache Feature installed
- BranchOffice Server (optional - in case of hosted cache): requires Windows Server 2008 R2 with BranchOffice Feature installed
- BranchOffice Client: requires Windows 7 clients
Deployment & Configuration
Deployment start and ends with the installation of the BranchOffice feature (using Server Manager – in R2 you can now connect remotely) on both Windows Server 2008 R2 File and/or Webserver(s) and optionally on your Windows Server 2008 R2 Branch office server (in case of the hosted cache).
Most client configuration is done through Group Policies, which makes it easy to deploy. However, BranchCaching at the FileServer needs to be activated on a per share basis (use Share & Storage Management). No configuration is required for the BranchCache at the WebServer.