Implementing a cache/proxy system

A cache/proxy server is typically a client-side server at the edge of the local area network (LAN) through which all streaming media requests are passed. The cache/proxy server stores the most recently streamed content for use by other clients seeking the same material. During live broadcasts, cache/proxy servers can perform a task called stream splitting which allows many unicast clients to receive content while only a single stream is sent from the origin server.

The three primary benefits of the cache/proxy system are:

• Reduces response times for all subsequent requests. Local networks are usually much more responsive than the Internet. Because the material is already maintained on the local network, the requests can be served locally.
• Reduces Internet traffic. Less traffic passing between the local network and the Internet means lower bandwidth requirements and a corresponding reduction in costs. On a larger scale, widespread use of cache/proxy servers can measurably reduce Internet congestion.
• Improves security. Network administrators have more control over streaming media usage and access if all requests pass in and out of a particular point in the system.

You must install a cache/proxy plug-in on your Windows Media server for the server to function as a cache/proxy server. A cache/proxy plug-in can be either obtained from a Microsoft Windows Media-based caching partner or created using the Windows Media Services Software Development Kit (SDK).

Under certain circumstances, streaming media content can be preloaded into the cache/proxy server's content database before the stream even begins. This process, called content replication, gives you the benefits of local media storage during a streaming media session.

Related topics

• Cache expiration - general properties
• Caching and proxying content
• Follow-up considerations
• Understanding content replication