Live Internet measurements using Westwood+ TCP congestion control

* This work was partially supported by the MIUR Research Project 488/92 C22 entitled "E-service to the Citizens" AbstractWestwood+ TCP is a sender-side only modification of the classic TCP that is based on end-to-end estimation of the bandwidth available to the connection in order to adaptively shrink the TCP congestion window and slow start threshold after congestion. In this paper we report measurements obtained using Linux implementations of Westwood+, Westwood and Reno to ftp data over Internet connections spanning continental and intercontinental distances. In particular we show that the bandwidth estimation algorithm employed by Westwood+ nicely tracks the available bandwidth, whereas the previous bandwidth estimation algorithm used by TCP Westwood fails to work in the real Internet due to ACK compression. Collected live Internet measurements also show that Westwood+ improves the goodput, from 10 to 46 % w.r.t. TCP Reno.