Patent ID: 6560237
Filing Date: 2003-05-06
Classification: H04L

Abstract:
A method of transferring a stream of messages received at an ingress port of a network device, the messages being destined for a destination network node, to an egress port of the network device in the same order in which the messages are received, comprising:upon receiving each message, (i) queuing the message to a first queue if a first service mechanism is being used to transfer the messages to the egress port, and queuing the message to a second queue if a second service mechanism is being used to transfer the messages to the egress port, and (ii) marking the queued message in a manner indicating a service era during which the message is being queued; advancing the service era upon at least every service transition from the first service mechanism to the second service mechanism occurring when the first queue is non-empty; monitoring the presence of messages in the first queue and the service era marking of messages transferred from the first queue to the egress port; and transferring each of said messages queued on said second queue from the second queue to the egress port only if at least one of the following conditions is satisfied: (i) there were no messages in the first queue at the time of the transition to the service era with which the message being transferred is marked, and (ii) none of said messages stored on said first queue are marked with service eras earlier than the service era with which the message being transferred is marked.