一个多功能路由查找引擎的设计与实现

针对网络边缘和接入层设备需处理多种网络协议和价格敏感的特点,文中介绍了一种能支持精确匹配和最长前缀匹配的多功能查找引擎。此引擎以五级环行多功能流水线为核心,通过SRAM接口与主机交互,采用ZBTSRAM作为路由表存储器。文中着重介绍了引擎的硬件结构、软件系统和软硬件联合验证方法。性能评测表明,基于FPGA的实现主频可达到50MHz,性能可以满足1Gbps￣2Gbps的接入和边缘层设备要求。

Design and Implementation of a General Routing Search Engine

For the network devices of access and edge layers,a low price network search engine for address lookup is described,which supports the longest prefix matching and exact matching with various configurations for different performance and price requests.While the five-stage multi-function cycle search pipeline as the kernel and route table being stored in the external ZBT SRAM,it communicates with the host CPU with standard SRAM interface.The hardware,software architecture and the software/hardware co-verification method of the engine are presented in the paper.With the implementation based on Xillinx' FPGA,it can run on 50MHz.12.5MSPS(Million Search per Second) for Ethernet MAC addresses and 7.2MSPS for IPv4 addresses are reached,which are satisfied with requests of access and edge network devices.