Agents Access Large Networks
By setting up a reverse tunnel from the cellular node’s care-of tackle to the house agent, you ensure a topologically right source address for the IP knowledge packet. A cellular node can request a reverse tunnel between its foreign agent and its house agent when the cell node registers. A reverse tunnel is a tunnel that starts at the cellular node’s care-of tackle and terminates at the home agent. The following illustration shows the Mobile IP topology that uses a reverse tunnel. When appearing as transmitter, a cell node sends packets directly to the opposite communicating node, with out sending the packets through the home agent, utilizing its permanent home address as the source tackle for the IP packets.
A mobile node registers with its residence agent utilizing a registration request message in order that its residence agentcan create or modify a mobility binding for that cell node (for example, with a brand new lifetime). The international agent can relay the registration request to the home agent. However, if the cellular node is registering a co-positioned care-of address, then the cellular node can ship the registration request directly to the home agent.
If the registration reply is legitimate, the Foreign Agent provides the Mobile Node to its visitor list, establishes a tunnel to the Home Agent, and creates a routing entry for forwarding packets to the home tackle. During the agent discovery phase, the Home Agent and Foreign Agent advertise their providers on the community by … Read More