An Efficient Queuing and Switching Scheme for Multicast in High-Speed Routers

Many emerging Internet applications are multicast traffic. The queuing and switc hing scheme for multicast in high-speed routers is one of the key elements to en able the multicast traffic traverse the complex network environments. Ideally in order to guarantee the fairness between the unicast and multicast traffic we sh ould not differentiate them deliberately when queuing and scheduling. Since the increase of multicast traffic will exhaust the resource, the service for unicast traffic will be influenced. When the two types of traffic coexist, how to provi de the fairness between them from the point of queuing view desiderates to be re solved. Based on the shared memory switching architecture, an efficient queuing scheme for multicast packet switching routers is proposed. And the corresponding buffer management and scheduling algorithm according to multicast ratio and fan out are also presented based on the proposed queuing scheme. On three phases, wh ich are the input buffer, the shared memory and the buffer of egress NP, the ban dwidth and buffer allocation for multicast packets is decided according to the m ulticast traffic ratio and the mean fanout. Performance evaluation of the propos ed system shows that better average delay and loss performance can be achieved i n comparison with the ESLIP system under heavy offered load, which is applied fo r high-end routers of Cisco.