  Connecting the wired and wireless networks particularly the Mobile ad hoc
Network is interesting in real world situations due to its usefulness and
practicality. Different mechanisms have been proposed to integrate MANETs and
the Internet. These strategies differ in gateway discovery mechanism, cell
switching criteria, ad hoc routing protocol.In this paper, Mobile-IP is
integrated with Hierarchical Cluster-Head Gateway Switch Routing (CGSR)
Protocol to provide Internet access to the mobile node of the ad hoc Network.
This paper discusses a mechanism for selecting an alternate route in case if
the Cluster Head is unable to forward the packets to the destination. The
proposed framework provides bi-directional connectivity between the MANET and
the Internet nodes. A detailed performance comparison is made between the
proposed approach and the other three-tier strategies based on mobility of
cluster heads and cluster gateways and other network parameters. The
experimental results indicate that the proposed architecture has better packet
delivery ratio, end-end delay and mobile node-gateway connectivity ratio for
providing full bi-directional connectivity.
