Information AboutMobile Ip |
| CATEGORIES ABOUT MOBILE IP | |
| network protocols | |
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INTRODUCTION Mobile IP provides an efficient, scalable mechanism for Roaming within the Internet. Using Mobile IP, nodes may change their point-of-attachment to the Internet without changing their IP address. This allows them to maintain transport and higher-layer connections while moving. Node mobility is realized without the need to propagate host-specific routes throughout the Internet routing fabric. Applications Mobile IP is most often found in wired and wireless environments where users need to carry their mobile devices across multiple LAN subnets with different IP addresses. It may for example be used in roaming between overlapping wireless systems, for example IP Over DVB , WLAN , WiMax and BWA . Currently, Mobile IP is ''not'' required ''within'' cellular systems such as 3G , to provide transparency when internet users migrate between cellular towers, since these systems provide their own data link layer Handover and Roaming mechanisms. However, it is often used in 3G systems to allow seamless IP mobility between different Packet Data Serving Node (PDSN) domains. For Release 8, MIP and different variations like PMIP will be supported by the EPS (Evolved Packet System), at least for non-3GPP accesses. In many applications ( VPN and VoIP , to name a few), sudden changes in network and IP-address can cause problems. HOW MOBILE IP WORKS In brief, Mobile IP works as follows. A mobile node can have two addresses - a permanent home address and a Care Of Address , which is associated with the network the mobile node is visiting. There are two kinds of entities in Mobile IP:
A node wanting to communicate with the mobile node uses the home address of the mobile node to send packets. These packets are intercepted by the home agent, which uses a table and tunnels the packets to the mobile node's care-of address with a new IP header, preserving the original IP header. The packets are decapsulated at the end of the tunnel to remove the added IP header and delivered to the mobile node. When acting as sender, mobile node simply sends packets directly to the other communicating node through the foreign agent. If needed, the foreign agent could employ ''reverse tunneling'' by tunneling mobile node's packets to the home agent, which in turn forwards them to the communicating node. The Mobile IP protocol defines the following:
Future Enhancements to the Mobile IP technique, such as Mobile IPv6 and Hierarchical Mobile IPv6 (HMIPv6), are being developed to improve mobile communications in certain circumstances by making the processes more secure and more efficient. Researchers are also working to create support for mobile networking without requiring any pre-deployed infrastructure as required by MIP. One such example is Interactive Protocol for Mobile Networking (IPMN) which promises supporting mobility on a regular IP network just from the network edges by intelligent signaling between IP at end-points and application layer modules with improved quality of service. SEE ALSO EXTERNAL LINKS
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