Patent ID: 6621818
Filing Date: 2003-09-16
Classification: H04L

Abstract:
A switching system for a packet-based data communications network, comprising:a crossbar-matrix switch, having a plurality of ports, and having a switching fabric for coupling packets received at one of the plurality of ports to one or more others of the plurality of ports; a plurality of switch devices, each having at least one local port, and having at least one high-speed port coupled to a corresponding port of the crossbar-switch matrix, and each of the plurality of switch devices comprising circuitry for applying a pretag to packets received at a local port and transmitted from the high-speed port, wherein the pretag corresponds to one or more of the plurality of ports of the crossbar-matrix switch to which the packet is to be forwarded; each of the plurality of switch devices further comprises address lookup circuitry for determining the value of the pretag to be applied to a packet received at a local port, responsive to a destination address of the received packet; the crossbar-matrix switch is also for generating a learning pretag upon a received packet, corresponding to the port of the crossbar-matrix switch received the packet, and for forwarding the received packet with learning pretag to another of its ports; and the address lookup circuitry in each of the plurality of switch devices associates the learning pretag of a received packet with a source address contained within the received packet.