I-D ACTION:draft-ietf-tcpm-tcp-dcr-01.txt

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the TCP Maintenance and Minor Extensions Working Group of the IETF.

	Title		: Improving the robustness of TCP to Non-Congestion Events.
	Author(s)	: S. Bhandarkar, A. Reddy
	Filename	: draft-ietf-tcpm-tcp-dcr-01.txt,.ps
	Pages		: 16
	Date		: 2004-7-15

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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