Locality-Aware Peer-to-Peer SIP

SIP (Session Initiation Protocol) is a signaling protocol widely used in multimedia communication. Recently, P2PSIP (Peer-to-Peer SIP), which combines DHT (distributed hash table) and SIP, has been proposed to overcome the drawbacks of traditional CS SIP (client/server architecture SIP). However, the introduction of DHT increases the registration overhead and, session setup overhead/latency. These problems become unbearable when P2PSIP overlay grows huge. To address these problems, we propose locality-aware P2PSIP in this paper. In the P2PSIP context, we design a locality-aware approach, which can be applied to most DHTs. This locality-aware approach reduces both DHT routing hop count and latency per DHT hop. Performance evaluation shows that registration overhead and session setup overhead/latency are reduced dramatically in locality-aware P2PSIP.