f the ID lies within the leaf set, the message is routed to the appropriate leaf set peer. If the ID is not within the leaf set, the searching peer computes the length l of the longest matching prefix between the search ID and its own peer-ID. The peer then looks in its Bamboo routing table at row 1. If there is an entry in that row corresponding to the l length prefix of the ID being searched for, then the message is forwarded on to that peer. If that Bamboo routing table entry is empty, the message is routed to the peer in its leaf set with the peer-ID that is numerically closest to the ID being searched for [22]. 9.6 Concluding Remarks The goal of P2P SIP is to allow true P2P networking between SIP peers by using SIP as the signaling protocol. The concept behind P2P SIP is to leverage the distributed and failure-tolerant nature of P2P by building an overlay network above SIP to provide P2P services for a network of SIP peers. This removes the need for centralized server components and allows true P2P networking between the SIP nodes. Several tentative Internet-drafts have been © 2009 by Taylor & Francis Group, LLC P2P SIP: Network Architecture and Resource Location Strategy made for P2P SIP, describing the overall architecture, the environment of the system, the architectural design of the overlay network, and the resource location strategy. As pointed out by D. Bryan and B. Lowekamp [23], P2P SIP will not be a replacement for SIP. It is an enhancement and companion to SIP, enabling SIP to be used in scenarios where it might not have otherwise been eas- ily deployed. P2P SIP is available now from a number of vendors, but is at the beginning stage of the adoption. Various implementations are still pro- prietary, but the standardization work of the IETF will improve the situa- tion. P2P SIP is becoming a powerful tool in various applications, such as in VoIP for small-enterprise systems, disconnected and ad hoc deployments, and global, decentralized deployments. It is also a strong contender for a protocol in IP