MECHANISM FOR DISPATCHING PACKETS VIA A TELECOMMUNICATIONS NETWORK

摘要

A mechanism for dispatching a sequence of packets via a telecommunications network includes a queue for packets for transmission and a queue controller res ponsive to receipt of a new packet for transmission to compare parameters of the new pac ket to parameters of any packet already in the queue, the queue controller determining whether to queue or drop the new packet depending on the result of the comparison(s). Th e queue can be implemented as a linked list of packet entries with individual poin ters to the respective packets concerned. The queue entries can include details relating to the packet including data relating to the information flow and also the packet ident ity. In a TCP environment, the flow information can include the source IP address and th e source TCP port, as well as the destination IP address and the destination TCP p ort. The identity information can include sequence numbers and acknowledgement number s for the packet concerned. In order to optimize network usage, it can be useful t o drop some packets at a routing node. A decision to drop a packet can be made if the n ew packet and a queued packet relate to the same information flow, the new packet s equence number equals the queued packet sequence number and the new packet acknowledgeme nt number is less than the queued packet acknowledgement number. The new packet is dropped where the new packet is a retransmission of a queued packet and the leng th of the queued packet is greater than or equal to that of the new packet. A queued p acket is replaced by a new packet when the new packet is determined to be a retransmis sion of the queued packet and the length of the new packet is greater than that of th e queued packet.