ISPRP: A Message-EfEkt Protaco1 for InitiakingS~P2P Networks.

Most research activities in the field of peer-to-peer (P2P) computing are concemed with routing in virtuaiized overlay networks. These overlays generally assume node connectiviq to be provided by an underlying network-layer routing profacol. This duplication offunctionality can give rise to severe ineficiencies. In contrast, we suggest a cross- layer approach where the P2P overlay network also pm- vides Ihe required network-layer routing fiinctionolity by itse$ Especially in sensor networks, where special atten- tion has to be paid to rhe nodes' limited capabilities, this can greatly help in reducing the message overhead. In drispapel; wepresent a key building block for such a protocol, rhe Iterative Successor Pointer Rewiring Protocol (ISPRP), which eficiently initializes a P2P rouririg network among a freshly deployed set of nodes having but link-layer connectivity. lSPRP works in a fdy selforgatzizing way and issues oiily a srnall per-node ainounf of messages by keeping interactions between nodes as local as possible.