Subject: I-D ACTION:draft-tcp-dcr-00.txt

From: [email-masked]
Date: Thu, 16 Oct 2003 15:29:42 -0400

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title		: Improving the robustness of TCP to Non-Congestion 
			  Events
	Author(s)	: S. Bhandarkar, et. al.
	Filename	: draft-tcp-dcr-00.txt
	Pages		: 16
	Date		: 2003-10-16
	
This document proposes TCP-DCR, a simple modification to the TCP
congestion control algorithm to make it more robust to non-congestion
events. In the absence of explicit notification from the network, the
TCP congestion control algorithm treats the receipt of three
duplicate acknowledgements as an indication of congestion in the
network. This is not always correct, notably so in wireless networks
with channel errors or networks prone to excessive packet reordering,
resulting in degraded performance. TCP-DCR aims to remedy this by
delaying the congestion response of TCP for a short interval of time
tau, thereby creating room to handle any non-congestion events that
may have occurred. If at the end of the delay tau, the event is not
handled, then it is treated as a congestion loss. The modifications
themselves do not handle the non-congestion event, but rather rely on
some underlying mechanism to do this. This document discusses the
implications of delaying congestion response on the fairness, TCP-
compatibility and network dynamics, and the benefits to be gained by
applying the TCP-DCR modifications to TCP.

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