A FC/AL-Based P2P network for personal archive and sharing

Abstract

Peer-to-Peer (P2P) networking technology can share a variety of contents, including the broadcast TV/Film programs. With the popularity of personal video recorders, people stores their favorite TV/film titles in the hard drive. It is clear that these recorders can easily archive and share TV/film contents over P2P networks once they are equipped with broadband connections. This is important because this emerging P2P network can provide an alternative content archive and distribution channel to the conventional unidirectional broadcasting. In other words, people can have another way to obtain TV contents that they were not able to record at the time of broadcast or purchase via the conventional DVD sale. As part of on-going research, we demonstrate that Fibre Channel -Arbitration Loop (FC-AL) technology can serve well as the storage network for personal archive and real-time content distribution. In our proposed architecture for TV content archive and sharing, the FC-AL directly connects many digital video recorders, a pool of network disks, and a content managing server. Via our integrated storage/network architecture, users can share their archives either from their own digital video recorders or the pool of networked disks. The results are the significant time-shifting for the users to watch the programs. The proposed network architecture also relieves the storage limitation of the digital video recorders, and users can help each other by archiving the "hard-to-find " contents. In this paper we present the technical schemes to fully utilize the performance of this emerging network. These schemes include (1) Buffering schemes to guarantee the concurrent video streams; (2) Matching schemes for communication pairs; (3) Load- balancing schemes; and (4) multipleloop staging schemes to extend the time-shift. With the effective buffering schemes, we have demonstrated over 300 high-quality video streams can be supported by the system with less than ldisplayjitters. To maximally utilize the FC-AL bandwidth and full-duplex property in both directions, we have developed effective schemes to match the communication pairs between users and the pool of network disks. It is also a common situation that most playback requests are concentrated on a few popular programs. From the perspective of overall system performance, such a skewed access pattern may cause serious load-unbalancing problems because some overloaded PVRs can become performance bottlenecks even though there are still many disks having sufficient available bandwidth. To solve this problem, we switch playback requests as well as replicate popular program (as minimally as possible). Finally, efficient staging methods have been proposed between the networked disks in different FC-AL loops to successfully extend the time-shift from 3-day to 70 days.