1.6 Applicability Statement
Enterprise branch offices typically connect to headquarters over low-bandwidth/high-latency wide area network (WAN) links. As a result, WAN links are generally congested, and application responsiveness in the branch is poor as well. The Peer Content Caching and Retrieval Framework (or Framework), which uses the Retrieval Protocol, is best suited when there is a need to reduce load on a content server or reduce bandwidth usage on the link between the peers and the content server. This is because the protocol enables downloading data from peers on the high-speed link instead of the content server, which might be behind a slow link or might be heavily loaded.
To increase responsiveness, the hosted cache is placed in the branch. The hosted cache then caches content and serves that content to peers in the branch that request it. Data gets added to the hosted cache by clients in the branch. Clients check to see if data is available in the hosted cache; if not, they retrieve data from the content server across the WAN link and subsequently add it to the hosted cache.