Method of cache replacement for streaming media

摘要

A system and method of cache replacement for streaming multimedia is provided. A network system includes a content provider connected to local service providers via an interactive distribution network, such as the Internet. The local service providers facilitate delivery of the content from the content provider to multiple subscribers. For each of the data blocks which make up the multimedia stream requested by a subscriber, the local service provider receiving the request determines whether the request can be serviced locally or whether the requested data blocks must be retrieved from the content provider. In the case where the portion of the requested stream must be retrieved from the content provider, the local service provider attempts to cache the requested blocks in its local cache in addition to streaming the data blocks to the requesting subscriber. The local service provider stores two lists to determine which cached block is to be replaced from the local cache memory in the case where the attempt to cache the requested blocks fail because the local cache memory is full. A first list defines those cached blocks for which there are no foreseeable future subscriber requests. The second list defines those cached blocks whose access time from existing suscribers is furthest in the future.