AdSIP: Decentralized SIP for Mobile Ad hoc Networks

Abstract

SIP (Session Initiation Protocol) is an IETF signaling protocol designed to create, modify and terminate sessions between two or many users in multimedia applications. The implementation of SIP needs the use of proxy servers which are centralized entities to route SIP requests and responses to enable user endpoints to discover each other. However, the infrastructureless of ad hoc networks requires that the network nodes support the tasks of participants’ discovery and SIP routing messages. In this paper, we propose the AdSIP protocol which is a completely distributed architecture for SIP that implements the proxy servers in selected nodes. The proxy servers are selected using a distributed algorithm constructing a connected minimal global offensive alliance. AdSIP is implemented and compared under NS-2 with another protocol which uses a cluster based approach. The simulation results show the advantages of AdSIP and demonstrate that it is adapted to mobile ad hoc networks by giving low session establishment time, low control overhead and high service availability.