Design of Scalable and Multicast Capable Cut-Through Switches for High-Speed LANs

High-speed switches play an important role in building switched LANs. Among different techniques used in switch design, cut-through switching promises short latency delivery and thus is well suited to distributed/parallel applications. The back pressure flow control of cut-through switching also prevents packet loss due to buffer overflow. This paper presents an incremental switch design based on modular building blocks using cut-through switching technique. The switch can be either nonblocking with full configuration and deterministic routing, or blocking but having more flexibility in configuration and fault tolerance. A kind of switch configuration that fits the client/server computing paradigm is presented. Simulation results are given for various switch configurations and traffic loads. The switch also has built-in hardware multicast capability. Issues of physical layout and integration into practical LANs are also discussed.