Patent ID: 6690668
Filing Date: 2004-02-10
Classification: H04L

Abstract:
A method of switching message packets in a data communications network by way of a switch system having a first plurality of switch devices coupled into a first switch ring, each of the first plurality of switch devices having a unique ring ID value for the first switch ring, and a second plurality of switch devices coupled into a second switch ring, each of the second plurality of switch devices having a unique ring ID value for the second switch ring;wherein the first plurality of switch devices includes a first high-speed switch device having a first high-speed port coupled in the first switch ring to high-speed ports of the first plurality of switch devices in the first switch ring, the first high-speed port having a unique ring ID value for the first switch ring, the first high-speed switch device also having a second high-speed port coupled to the second switch ring; and wherein the method comprises the steps of: receiving a message packet at a local port of a first switch device in the first plurality of switch devices, the first switch device associated with a unique ring ID value for the first switch ring, and the message packet having a destination address; comparing the destination address of the received packet to a registry of destination addresses associated with ports of the first switch device; responsive to the destination address being associated with a high-speed port of the first switch device, attaching a ring ID pretag to the received packet, the ring ID pretag having a value corresponding to the ring ID value of the first switch device, and transmitting the packet and pretag from the high-speed port of the first switch device to a high-speed port of an adjacent switch device in the first switch ring; then, for each of at least one subsequent switch device in the first switch ring, performing the steps of: receiving the message packet at a high-speed port of the subsequent switch device; comparing the ring ID pretag of the received packet to the ring ID value of the subsequent switch device; responsive to the ring ID pretag not corresponding to the ring ID value of the subsequent switch device, comparing the destination address of the received packet to a register of destination addresses associated with ports of the subsequent switch device; responsive to the destination address of the received packet being associated with a local port of the subsequent switch device, removing the ring ID pretag from the packet, and transmitting the packet from the local port of the subsequent switch device; and responsive to the destination address of the received packet not being associated with the high-speed port of the subsequent switch device, transmitting the packet and ring ID pretag from the high-speed port of the subsequent switch device to a next adjacent subsequent switch device in the first switch ring; and upon the packet and pretag reaching the first high-speed port of the first high-speed switch, and responsive to the destination address of the received packet being associated with the second high-speed port of the first high-speed switch device, removing the ring ID pretag from the packet, and transmitting the packet from the second high-speed port of the first high-speed switch device.