Patent ID: 7146430

Claim:
A network system including comprising: a plurality of paths; and at least one cache server, the at least one cache server comprising: a quality-of-service (QoS) path information obtaining section for obtaining QoS path information including network path information and path load information, a path calculating section for identifying a candidate path suitable for carrying out at least one of an automatic cache updating operation, a link prefetching operation, and a cache server cooperating operation, based on the QoS path information obtained by the QoS path information obtaining section, wherein the path calculating section identifies the candidate path as having a maximum remaining bandwidth of the plurality of the paths and identifies a link on the candidate path that has a minimum remaining bandwidth, and at least one of an automatic cache updating section, a link prefetching control section, and a cache server cooperating section, which carry out respective ones of the automatic cache updating operation, the link prefetching operation, and the cache server cooperating operation by using the candidate path identified by the path calculating section when the minimum remaining bandwidth is not smaller than a predetermined value.