Standards-Based P2P Communications Systems

David A. Bryan, Department of Computer Science College of William and Mary, and Bruce B. Lowekamp, Department of Computer Science College of William and Mary

6/13/2008
(Original Publish Date: 9/1/2005)

Current Voice over IP (VoIP) and Instant Messaging (IM) systems follow a client-server model, or require clients and network elements supporting non-standard protocols. In this paper, we present a standards-based, fully decentralized peer-to-peer (P2P) communications system. This system can be used in situations where constant Internet connectivity is not possible, and supports ad hoc, ephemeral communications scenarios. These systems are useful in environments including remote locations, security conscious organizations, and collaborative groups. Our system leverages the existing SIP/SIMPLE family of open-standard protocols, ensuring that our system will interoperate with existing communications infrastructure. We implement our system using a Distributed Hash Table (DHT) approach for lookup, transported using SIP messages. We support replication for reliability and availability. Our system uses unmodified SIP/SIMPLE mechanisms to exchange messages after resources are located, allowing for maximal reuse. We explore future directions of research for such systems, including security, availability, and advanced routing, including social-based routing techniques.