SIP Instant Messaging Reasearch And Design Based On IPv4/IPv6 Hybrid Network

With the continuous development of multimedia and network technology, computer network, television network and telephone network are being integraetd gradually.At the same time, with the rapid growth of the number of Internet users, the existing IPv4 addresses are so scarce that it will be replaced by IPv6.This makes the existing network architecture has been difficult to meet people's needs and applications. Therefore, NGN as the new next generation network came into being.In the next generation network, IPv6 will be used on network layer, and SIP will be used as the key protocol on application layer (SIP is simple, flexible and easy to expand and so on. It`s suitable for NGN). Obviously, IPv4-based software development platform nowadays will no longer adapt to the new network environment and will be upgraded or eliminated in the future.IPv4 and IPv6 are`t compatible because of different header structure. So the host in the IPv4 network and the host in the IPv6 network can`t communicate directly. It`s a long time for IPv4 being replaced by IPv6,so IPv4 and IPv6 will coexist for a long time. Therefore, how to solve the problem of data transmission between IPv4 and IPv6 network is the key point. And the research of transition strategy from IPv4 to IPv6 has an important meaning and value.This paper focuses on heterogeneous IPv4/IPv6 hybrid network, based on double protocol stack and network address protocol conversion technique, proposes SIP middleware components data transmission solutions based on hybrid network.. And the SIP IM system based on hybri network is designed for my paper as a demo of thesis argument. The server of system is responsible for address resolution, data relaying, check positions and so on, and the client includes text chat in hybrid network, voice chat, large file transfers, etc. A middleware component is designed in the system to shield the differences of address structure, which is independent of the underlying protocol. After a number of experiments. The system demonstrates that the solution of SIP-based middleware technology of NAT-PT (network address-protocol translation) for data transmission among heterogeneous networks is feasible and reliable.