Web Browsing with HTTP (Including HTTPS)

HTTP and HTTPS are the standard protocols that Web browsers use. With HTTP or HTTPS and BranchCache, intranet Web pages can be cached in the branch office and retrieved by other clients on the local network. BranchCache provides a separate cache from the cache built into Windows Internet Explorer. The Internet Explorer cache is accessible only to the current user, whereas BranchCache is accessible to other users at the same branch.

BranchCache is not designed to be used with Internet Web pages. For HTTP caching to be supported, the Web server must be using Windows Server 2008 R2 with IIS. Only content marked as cacheable will be stored using BranchCache. Typically, this allows the most bandwidth-intensive Web content types to be cached, including static HTML pages, documents, images, sounds, and videos.

For example, consider a scenario in which Human Resources posts a video for all employees to watch. If that video is hosted on a Web server with BranchCache enabled, the first and second clients to view the video can download it from the intranet Web server across the WAN. The second client stores a copy of the video in the cache. Then, the third and subsequent clients download a small identifier from the intranet Web server and retrieve the full video directly from the cache.

Because each page might be different, most dynamically generated Web pages cannot be cached. However, BranchCache can still reduce WAN bandwidth usage by caching static images referenced in the page.