Patent ID: 7298756
Filing Date: 2007-11-20
Classification: G06F,H04L

Abstract:
1. In a packet communications switch fabric, a method for controlling packet header information, the method comprising: accepting a packet including a plurality of cells and corresponding cell headers, each cell header including a plurality of overhead fields; defining the cell header overhead (OH) fields; redefining the cell header overhead fields as follows: modifying OH field information; relocating OH fields in the cell header; adding OH fields to the cell header; extracting OH field information; reformatting the OH fields; transmitting the packet; wherein accepting a packet including a plurality of cells and corresponding cell headers includes: wherein transmitting the packet includes: wherein accepting packets at an input port card ingress port includes buffering the packets in an ingress memory subsystem (iMS); wherein redefining the cell header OH fields includes redefining the cell header OH fields buffered in the iMS; wherein routing information packets between the input port card on backplane data links through an intervening crossbar includes; wherein redefining the cell header OH fields includes redefining the cell header OH fields buffered in the eMS; wherein routing information packets between the input port card on backplane data links through an intervening crossbar includes an IPC ingress priority queue (iPQ) managing the backplane data links; and, wherein transmitting the packet includes: wherein redefining the cell header OH fields buffered in the iMS includes; wherein redefining the cell header OH fields buffered in the eMS includes: wherein the iMS defining a seventh field embedded in an eighth field includes the iMS embedding dummy port information, selected from a plurality of unused OPC egress ports, in the OH fields; and, wherein the eMS extracting information from a seventh field embedded in an eighth field includes the eMS extracting the dummy port information; wherein an OPC iPQ relaying backplate control information from the eMS to the IPC iPQ includes the eMS sending the dummy port information; and, wherein routing packets between the input port card and the output port card on backplate data links, through an intervening crossbar includes the IPC iPQ using the dummy port information in the management of the backplane data links.