Understanding Mobile IP: A Comprehensive Tutorial

As internet demand grows worldwide, maintaining device internet connectivity while moving is crucial. This is achieved using the Mobile IP concept, applicable to both wired and wireless connections.

In wired scenarios, a Mobile IP device can be unplugged from one connection point and plugged into another. However, Mobile IP is particularly well-suited for wireless connections.

In non-Mobile IP systems, users moving between locations must terminate and re-establish their IP connection each time, receiving a new temporary IP address for all applications.

Mobile IP systems, however, keep users connected to their applications despite movement. The connection is maintained automatically. Figure 1 illustrates a typical Mobile IP scenario where mobile node-A moves between locations.

As shown, mobile node-A is assigned to a specific network, its home network. The IP address assigned here is the home address, which is static. When the host moves to another network, the foreign network, it registers with that network through a router called the foreign agent.

The mobile node communicates its care-of address to the home agent, informing it of the foreign agent’s location. This facilitates the exchange of IP datagrams across the Mobile IP network.

Mobile IP Protocol

To support IP datagram communication, Mobile IP utilizes the following capabilities:

• Discovery: Mobile nodes use a discovery procedure to identify potential home and foreign agents.
• Registration: Mobile nodes use a registration procedure to inform their home agent of their care-of address while moving.
• Tunneling: This forwards IP datagrams from the home address to the care-of address location.