A Decentral Architecture for SIP-based Multimedia Networks

The Session Initiation Protocol (SIP) is a general protocol for session setup and management, e.g., for VoIP. Current SIP networks build on a fixed infrastructure that relies on static network entities. General problems with this infrastructure, e.g., in ubiquitous ad-hoc networks, lead to a trend of integrating peer-to-peer mechanisms into SIP. We propose a generic architecture for decentralised SIP networks. The SIP location service of our architecture is based on JXTA for message routing. This allows SIP networks without central location services, and in extreme even without central SIP proxies. Unlike other approaches, we do not modify SIP. Thus, standard SIP clients can be seamlessly integrated. Due to the flexibility of JXTA, various peer-to-peer algorithms can be integrated according to current requirements. Additionally, our architecture supports registration, discovery and locating of services based on SIP. This saves resources in end terminals and also benefits from the peer-to-peer approach.