Patent ID: 8438215

Claim:
A content delivery system comprising: a content distribution site that distributes a playback request from a user terminal, a cache server connecting the content distribution site and a user terminal, and temporarily storing the content distributed from the content distribution site, and a cache control server that manages the content held by the cache server, wherein the cache control server includes: a cache control unit that determines a possibility of resuming playback of the content after stopping the content based on a playback status of the content of the user terminal, and sets a delete inhibit span of the content stored in the cache server according to a result of the determining the possibility of resuming playback of the content after stopping the content, the cache control unit having a delete inhibit span setting unit that sets the delete inhibit span based on the stop position; a delete inhibit span notification unit that notifies the content delete inhibit span of the cache server and; a message processor that acquires a position at which the user terminal stopped during playback of the content as a playback status; and wherein the cache server includes: a storage device that temporarily stores the content distributed by the content distribution site to the cache server; a content providing unit that sends the content stored in the storage device to the user terminal; a delete priority management unit that sets a delete priority for the content stored in the storage device based on the delete inhibit span received from the cache control server; and a content management unit that deletes content based on previously set delete priorities set by the delete priority management unit, when new content is stored from the content distribution site and there is no vacant area in the storage device of the cache server.