Patent ID: 7929423

Claim:
A method for synchronizing transmit frame fragment sequence numbers of an active transmitter and a standby transmitter on line cards in a switch supporting a multilink protocol having an active side and a standby side, said method comprising; initializing a standby transmit sequence number for the standby transmitter to an initial value; incrementing said standby transmit sequence number with each transmit frame fragment handled by the standby transmitter; associating said standby transmit sequence number with respective receive sequence numbers received by the switch; determining an association of transmit frame fragment sequence numbers used by the active transmitter for respective receive sequence numbers received by the switch, wherein the standby side is informed of an association between the transmit frame fragment sequence numbers and receive frame fragment sequence numbers; calculating an offset to said standby transmit sequence number based upon a difference between said standby transmit sequence number associated to a specific receive sequence number and an active transmit frame fragment sequence number associated to the same specific receive sequence number; and applying said offset to said standby transmit sequence number to bring said standby transmit sequence number in synchronization with transmit sequence numbers of the active side.