Switch-Borne Router for High Performance Packet Forwarding of Connectionless Tra c in ATM Networks

The most viable support for connectionless tra c over ATM uses connectionless servers that forward packets based on the destination address in each packet. To achieve high data rates with small latency and predictable cell delay variation, this forwarding process must be carried out e ciently. This paper proposes a functional architecture, called switch-borne router (SBR), which incorporates connectionless routing and forwarding into the ATM switching architecture. With SBR, it is possible { using an e cient cut-through technique { for a connectionless service to forward packets at near-ATM speeds with a negligible amount of added latency per packet (or burst). Router bu ering, which adds complexity, can be substantially reduced through a simple tra c shaping technique. Furthermore, SBR requires only minor changes to the switch architecture, and allows for seamless integration of connection-oriented and connectionless tra c.