Service Availability for Various Forwarded Descriptions with Dynamic Buffering on Peer-to-Peer Streaming Networks

In P2P systems, because the buffer space of each peer is limited, most of P2P systems employ the cache-and-relay schemes that require each peer to cache the most recent video stream it receives. As long as the initial part of the video stream remains in its buffer, the peer can then relay the cached stream to late-arriving peers in a pipelining fashion and then the loading of a server is reduced. In our previous research work, we proposed a novel caching scheme for peer-to-peer on-demand streaming, called Dynamic Buffering, which relies on the feature of Multiple Description Coding to gradually reduce the number of cached descriptions in a peer once the buffer is full. In this paper we discuss service availability of a peer with dynamic buffering for various numbers of kinds of forwarded descriptions, and provide detailed analyses on how the number of kinds of forwarded descriptions affects average service availability of a peer. In addition, the mathematical formulas of the reduction of average service availability for various numbers of kinds of forwarded descriptions is derived. Our experiment results showed that the reduction of average service availability is only related to the number of kinds of forwarded descriptions.