METHOD AND APPARATUS FOR CACHING A MEDIA STREAM

A system and method for caching media streams at proxy servers. In the current invention, blocks received for a media stream are grouped into segments by the proxy servers, where the cache admission and replacement policies attach a different caching value to different segments, taking into account the segment distance to the start of the media object. These policies give preferential treatment to the beginning segments and may take into account other considerations such as the media object reference frequency, time since the last reference to the object, or its access time. According to the invention, the proxy server is enabled to cache a subset of the segments, which will generally be the beginning segments. According to another aspect of the invention, if only a portion of a media stream is cached in the proxy server when the stream is requested, the remaining segments are prefetched. Thus, upon receipt of a media request, the proxy can immediate serve the request using the segments cached, and compose and issue a prefetch request to obtain the remaining blocks for segments which are not currently cached.