subject: Mobile Ipv6 Technology Status [print this page] Abstract Mobile IPv6 technology first introduced by doing, describes the advantages of Mobile IPv6, as well as domestic and foreign R & D status. Finally, 3G mobile IPv6 and the development of our relationship were analyzed.
With the development of data applications faster and faster, IPv4 protocol gradually exposed many shortcomings. Too few to address the specific performance, rapid expansion of the routing table, configuration is too complex, lack of security guarantees, QoS and performance, inadequate protection, mobility support is not enough and so on. Therefore, IPv4 can no longer satisfy the basic data applications. The emergence of IPv6 data applications and brings the dawn, while IPv4 is exposed for all the disadvantages of providing a good solution. In particular, its almost unlimited number of addresses, makes the mobile terminal to meet the massive demand for the address, and its mobility has increased a lot more than IPv4.
1, the origin of Mobile IPv6
IPv4 early in the design and did not take into account the mobility of the terminal device, so mobile networking equipment needed to disconnect from the Internet. In another place to reconnect, you also need to re-configure the system's new IP address, the correct subnet mask, and the new default router (gateway) in order to continue communication.
Cause this problem because the IPv4 routing mechanism. IPv4 addresses on the Internet today is actually processed layer by layer. The core of the network, the router is not for individual users to be processed, but only see the beginning of a number of IP addresses (network prefix), and forward the packet to a particular network. The network router address after several further view, and then send the packet to the subnet. To the edge of the network when the access routers see the last part of the address and send packets to a specific machine.
IP address by this resolution to urge the device layer of fixed access to a subnet, and will not move between the larger network. If you cut off a computer with a subnet connection, and connect to another subnet, the computer's IP address must change. Similarly, if a business changed ISP, the entire network had to change of address.
Many client machines do not have a permanent IP address, but each time you log a network to obtain a new address. For example, most notebook computers need access to the Internet has two IP addresses, one in the office network access to the address, one ISP at home access to a network of address.
When the user is not often switch between networks, and do not mind out of the network re-login when there is no problem in this way. However, if the user needs to move in the network to maintain connectivity between, this approach would be a problem. For high-level protocols (such as TCP) is to use IP addresses to identify users, if IP address has changed, the user can not maintain a TCP connection.
To support mobile devices on the Internet, IETF introduced the Mobile IP standards, allowing users to retain the same permanent IP address, regardless of whether they are connected to the Internet. Mobile IP has two: one is based on the IPv4 Mobile IPv4, one is IPv6-based mobile IPv6. Mobile IP was originally defined for IPv4 (IETFFRC2002). At the time requirements are: IPv4 mobility support is added, the vast majority of IPv4 nodes do not support mobile IP. Today on IPv6 mobility requirements are: Mobility is an integral part of IPv6 and one of the important features, IPv6 deployment is expected that all will include at least the smallest mobile IP support (ie communication node function).
In mobile IPv6, mobile nodes in the current matter how and where the access to the Internet is, after all, through its static home address to identify the node. Leave the home network, each mobile node will obtain another temporary address to that node's current location.
