IP组播在路由交换机上的实现改进和计费策略研究

路由交换机融合了二层的交换和三层的路由技术,以其硬件转发的高效率和低成本优势,迅速在宽带网市场中占据了巨大份额。IP组播将一个流同时发送给多个接收者,以较小的带宽提供多媒体业务。针对在路由交换机上实现IGMP组播时遇到的问题,提出了在VLAN内隔离端口间组播报文和基于端口转发报文的方案,优化了交换机的性能,并扩展了RADIUS认证报文属性,在接入层交换机上控制用户IGMP和组播数据报文,实现了组播业务的用户认证,提供了一种可运营的IP组播业务的认证和计费方案。

Integrating Layer 2 switching and Layer 3 routing together, and with higher forwarding speed and lower cost of the hardware, routing switch has obtained a great share in broadbaad network market. By sending a single stream to a group of receivers, IP multicast provides multimedia services on a considerably lower bandwidth. Based on problems emerging in the implementation ofIGMP multicast, this article puts forward a new method to optimize the performance of routing switch by insulating graphs broadcasting between ports inside a single VLAN and forwarding graphs to each required port. It also extends the properties of RADIUS （Remote Authentication Dial In User Service） authentication graph, controls IGMP protocol packet and mditicast data graph on user access layer switch, and achieves an op erative solution of authenticating and accounting IP multicast services.