Patent ID: 6628655
Filing Date: 2003-09-30
Classification: H04L,H04Q

Abstract:
A method comprising the steps of:a) checking whether a data frame moving through an ingress switching node in a data transmission network wherein Internet Protocol (IP) data frames are transmitted between a sending unit connected to the ingress switching node and a receiving unit connected to an egress switching node, the ingress switching node being linked to the egress switching node by a plurality of intermediate switching nodes interconnected by trunks and each of the ingress switching node, egress switching node and intermediate switching nodes including a switch engine in charge of switching any data frame from an input port/trunk interfacing the switch engine by an input port/trunk interface to an output trunk/port interfacing the switch engine by an output trunk/port interface and a router interfacing the switch engine by a router interface in charge of routing each flow of data from an ingress switching node to an egress switching node when the first data frame of said flow of data is received by the ingress switching node by looking up an input table in the input port interface of the ingress switching node whether said data frame belongs to a known flow of data, b) generating, in the input port interface, a first switch header including a source identification field, a destination identification field and a temporary label identifying the flow of data in response to the first data frame, the first switch header being concatenated to the data frame, c) transmitting the data frame with the concatenated first switch header to the router interface via the switch engine when the data frame does not belong to a known flow of data, d) storing the source identification and temporary label contained in the first switch header in a buffer of the router interface before transmitting the data frame to the router for defining routing of the flow of data to which the data frame belongs, e) comparing all data frames received by the router interface from the router with all the source identifications stored in the buffer to determine the data frame to be routed, f) generating a second switch header including the source identification field and the temporary label for the data frame, and a destination identification field determined from the routing information provided by the router, the second switch header being concatenated to the data frame, g) transmitting the data frame with the concatenated second switch header to the output trunk interface defined in the destination identification field of the second switch header via the switch engine, and b) sending back an update message from the output trunk interface to the input port interface via the switch engine to update the input table with a switching label associated with the flow of data and the destination identification while the data frame with a corresponding routing label is transmitted by the output trunk interface over the network.