本文介绍了基于IXP1200网络处理器进行城域以太交换系统数据通道的设计,在以太交换的基础上,实现了独特的 EVC连接功能。文中描述了具体的系统结构,任务结构,相应的数据结构以及该城域交换系统数据层面的逻辑流程 框图;同时说明了基于网络处理器的设计方法和步骤。本文基于网络处理器实现的城域以太交换系统可提供点到点 和多点到多点的EVC连接。 This paper introduces the IXP1200 network processor for metro Ethernet switching system data channel design, based on the exchange of the Ethernet, to achieve a unique EVC connectivity. The paper describes the specific system structure, the task structure, the corresponding data structure and the logical structure of the data exchange layer of the metro system; at the same time describes the network processor-based design methods and steps. In this paper, the metro Ethernet switching system based on network processor can provide point-to-point and multi-point to multi-point EVC connection.