A multicast push caching system over a UDLR satellite link

Abstract

We propose an extension of the AI3 CacheBone to include a unidirectional satellite network that deploys multicast push technology of cache objects on the satellite link. The scheme aims to provide effective use of unidirectional links in order to distribute cache contents from the hub station to a large number of rim caches at the receiving ends of the satellite communication. Added to the AB CacheBone is a push server placed at the hub station which acts as a proxy to fetch Web objects from the original Web servers and forward them to rim caches. With a unidirectional link routing protocol (UDLR), the rim caches are assumed to be on a network with terrestrial links back to the hub cache whose return paths to the hub may sometimes be through very thin dial-up connections/sub ./ Our primary objective is to make effective use of the satellite link to disseminate the Web contents to as many rim caches as possible, thereby placing Web contents closer to end users who may be in remote geographical areas with limited access to the Internet. Unlike the existing bidirectional AI3 CacheBone, inter-cache communications on thin return paths from the rim to the hub would be reduced, and would free the line for other applications. The push server, being on the high speed Internet, would actively collect up-to-date popular Web contents and disseminate them to member rim caches on a regular basis. The result of pushing Web contents to the rim cache increases the content of rim caches and thus reduces the number of requests from rim to hub caches.