This paper presents TCP rate control, a new technique for transparently aug
menting 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 affe
cts these aspects by modifying the ack(1) number and receiver window fields
in acknowledgments and by modulating the acknowledgment rate. From a perfo
rmance viewpoint a key benefit of TCP rate control is to avoid adverse perf
ormance 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 T
CP implementations are non-conforming. These aspects are demonstrated throu
gh a comparative study of TCP tate control, RED and TCP-ECN. The TCP rate c
ontrol approach has been implemented and patented by Packeteer Inc.