TCP Westwood: End-to-End Congestion Control for Wired/Wireless Networks

Abstract. TCP Westwood (TCPW) is a sender-side modification of the TCP congestion window algorithm that improves upon the performance of TCP Reno in wired as well as wireless networks. The improvement is most significant in wireless networks with lossy links. In fact, TCPW performance is not very sensitive to random errors, while TCP Reno is equally sensitive to random loss and congestion loss and cannot discriminate between them. Hence, the tendency of TCP Reno to overreact to errors. An important distinguishing feature of TCP Westwood with respect to previous wireless TCP "extensions" is that it does not require inspection and/or interception of TCP packets at intermediate (proxy) nodes. Rather, TCPW fully complies with the end-to-end TCP design principle. The key innovative idea is to continuously measure at the TCP sender side the bandwidth used by the connection via monitoring the rate of returning ACKs. The estimate is then used to compute congestion window and slow sta...

• Type: Journal
• Year: 2002
• Where: WINET
• Authors: Claudio Casetti, Mario Gerla, Saverio Mascolo, M. Y. Sanadidi, Ren Wang
• Keywords: Congestion Window, TCP Reno, TCP Westwood, WINET 2002