Limited Slow-Start for TCP with Large Congestion Windows
RFC 3742

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: Internet Architecture Board <iab@iab.org>,
    RFC Editor <rfc-editor@rfc-editor.org>
Subject: Document Action: 'Limited Slow-Start for TCP with Large 
         Congestion Windows' to Experimental RFC 

The IESG has approved the following document:

- 'Limited Slow-Start for TCP with Large Congestion Windows '
   <draft-ietf-tsvwg-slowstart-01.txt> as an Experimental RFC

This document is the product of the Transport Area Working Group. 

The IESG contact persons are Jon Peterson and Magnus Westerlund.

A URL of this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-tsvwg-slowstart-01.txt

Technical Summary
 
This note describes an optional modification for TCP's slow-start for use 
with TCP connections with large congestion windows.  For TCP connections tha
are able to use congestion windows of thousands (or tens of thousands) of 
MSS-sized segments (for MSS the sender's MAXIMUM SEGMENT SIZE), the current 
slow-start procedure can result in increasing the congestion window by 
thousands of segments in a single round-trip time.  Such an increase can 
easily result in thousands of packets being dropped in one round-trip time.  
This is often counter-productive for the TCP flow itself, and is also hard o
the rest of the traffic sharing the congested link.  This note describes 
Limited Slow-Start as an optional mechanism for limiting the number of 
segments by which the congestion window is increased for one window of data 
during slow-start, in order to improve performance for TCP connections with 
large congestion windows.

This document also compares the proposed approach with alternative solutions

 
Working Group Summary
 
Many solutions have been considered for addressing the known issues with TCP 
performance in a context of high congestion window sizes; this document form
a part of a larger HighSpeed TCP proposal. The community TSVWG welcomed the 
opportunity to further explore this Experimental mechanism, and supported th
advancement of this document.
 
Protocol Quality
 
This document was reviewed for the IESG by Jon Peterson.