Design And Implementation Of Layer3 Forwarding Based On Octeon Multi-core Network Processor

With the extensive application of wireless business and the rise of multimedia communication technology, network bandwidth demand is also increasing. Traditional WLAN AC (wireless LAN access controller) system is based on multi-core Octeon CN56XX network processor with 12 cores and the direct use of the routing forwarding strategy from Linux kernel has been difficult to meet the high-performance data transfer. In addition, the use of exchange-chip for hardware forwarding has no more than 2048 layer 3 forwarding entries. Therefore, in the study of WLAN AC, the method of L3 forwarding under the multi-core network processor needs to be reconsidered.This thesis describes the current status of research and summarizes some problems of the L3 forwarding method in WLAN AC system. Then, introduces the principle of the L3 forwarding, studies the packet processing, the operating mode, the hardware and software architecture of the multi-core network processors. On this basis, a new architecture is presented for the L3 forwarding reference. It is a software architecture implemented with separation of the control and data plane. The control plane plays as Slow Path to generate and maintenance L3 forwarding table. The data plane playes as Fast Path to do packet forwarding. The following is mainly completed:update strategy of the L3 forwarding based on the routing table and the neighbor table; synchronization between reading and writing based on named memory block; retrospective optimization based on LC-Trie for fast IP address lookup; multicore communication based on POW unit. Finally, comparative testing is made between the routing algorithm and packet processing program as a Linux user state program is compared with this project on the efficiency of packet forwarding. Analysing the test results, the L3 forwarding scheme is suitable for WLAN AC system, it has better performance and strong practicability.