The mobile Ad Hoc networks have become a major component of the future network development due to their ease of deployment, self configurability; flexibility and
independence on any existing network infrastructure Mobile ad-hoc network have the attributes such as wireless connection, continuously changing topology, distributed
operation and ease of deployment. Routing protocol election in MANET (Mobile Ad Hoc Network) is a great challenge, because of its frequent topology changes and routing
overhead. In mobile ad hoc network research, simulation plays an important role in determining the network characteristics and measuring performance. For this reason,
constructing simulation models closer to the real circumstances is very significant. For widening the coverage area of the MANET there is a growing need to integrate these ad hoc networks to the Internet. For this purpose we need gateways which act as bridges between these two different protocol architectures. The gateway discovery in
hybrid network is considered as a critical and challenging task. In this paper the AODV reactive routing protocol is extended to support the communication between the MANET and the Internet. We have carried out a systematic simulation based performance evaluation of the different gateway discovery approaches using NS2 under different network scenarios. The performance differentials are analyzed on the
basis of three metrics – packet delivery fraction, average end to-end delay and normalized routing load.
An Efficient Integrated Routing Protocol for Interconnecting Mobile Ad Hoc Network and the Internet