TCP rate control

This paper presents TCP rate control, a new technique for transparently augmenting end-to-end TCP performance by controlling the sending rate of a TCP source. The sending rate of a TCP source is determined by its window size, the round trip time and the rate of acknowledgments. TCP rate control affects these aspects by modifying the ack(1) number and receiver window fields in acknowledgments and by modulating the acknowledgment rate. From a performance viewpoint a key benefit of TCP rate control is to avoid adverse performance effects due to packet losses such as reduced goodput and unfairness or large spread in per-user goodputs. Further, TCP rate control positively affects performance even if the bottleneck is non-local and the end-host TCP implementations are non-conforming. These aspects are demonstrated through a comparative study of TCP tate control, RED and TCP-ECN. The TCP rate control approach has been implemented and patented by Packeteer Inc.