Optimized cooperation between resource list servers and presence servers

摘要

A method, system and computer program product for optimized cooperation between resource list servers and presence servers. The method including receiving a subscription request from a watcher, where the subscription request identifies a resource list and is a request to receive presence information regarding each of a plurality of presentities listed on the resource list, and generating a subscription request to a presence server for presence information regarding any presentity listed on the resource list only if no other currently-active subscription request is known by the resource list server to exist for presence information regarding the presentity.