COMMUNICATIONS NETWORK WITH CONGESTION AVOIDANCE

摘要

A packet network node and method of operating a packet network node are disclosed. Conventional packet network nodes react to congestion in the pack et network by dropping packets in a manner which is perceived by users to be indiscriminate. In embodiments of the present invention, communication sourc es precede communications with a start packet which contains a communication identifier also carried within subsequent packets of the communication. The packet network node makes an entry in a vulnerable communications table (6.4 ) on receipt of such a start packet. After an amount of time, and often before the cessation of a communication, such entries are removed from the vulnerab le communications table. On the onset of congestion, the packet network node disclosed herein deletes packets in communications identified in the vulnerable communications table. This provides a congestion alleviation meth od which is less annoying to users since communications that have been in existence for longer are less susceptible to component packets being deleted .