The Network Processor-based Ipv4/ipv6 Protocol Translation Gateway Design And Realization

As the fundamental protocol of network, IPv4 is widely used in Internet and countless smaller network. But as a result of the development of Internet, the address space of IP will exhaust in a short time. IPv4 also can't guarantee the Qos of network, do a good work for mobile nodes and keep the network secure. IETF published the new Internet Protocol version 6, we call it IPv6 for short, and relevant standards(RFC 1883-1887) in 1996. IPv6 is determined to be the protocol of network level in NGN(Next General Network).It's a very large work to change the network protocol of all the nodes in the world because of the huge scale of Internet. So, the migration to IPv6 must last a long time. The coexistence of IPv4 and IPv6 is inevitable. The key issue during the transition to IPv6 is to connect IPv6 network to traditional Internet correctly.A lot of new services and network protocols come forth while the bursting increment of Internet. The network equipments based on the software running on general purpose processor or the hardware of ASIC are difficult to meet flexibility and performance both. A new processor based on ASIP named network processor appeared. It provides the network facilitise flexibility and high performance, reduces the time to market and time to money by handling 2-7 level packets efficiently.The main purpose of this paper is how to resolve the problems may occur during designing a IPv4/IPv6 transition gateway. Based on the comparison of several issues of IPv4/IPv6 transition, we focus on the solution of NAPT-PT and how to implement it on IXP1200.Most of IPv4/IPv6 translation systems in the world run on general purpose processor. They are too unefficient to match the demand of backbone. There are limited achievements about applying network processor to IPv4/IPv6 translation in the world.In this paper, we give a solution on NAPT-PT to translate IPv6 to IPv4 for a network on MAN. We provide the procedure of how to realize the transition gateway on the hardware system core on Intel IXP1200. The measurement proves it can translate the protocol correctly and forword packets in line speed on the port. It suits the qualification of backbone.