Increasing TCP's Initial Window

Document Type Replaced Internet-Draft (individual)
Authors Jerry Chu  , Nandita Dukkipati  , Yuchung Cheng  , Matt Mathis 
Last updated 2012-04-19 (latest revision 2010-07-12)
Replaced by RFC 6928
Stream (None)
Intended RFC status (None)
Expired & archived
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IESG IESG state Replaced by draft-ietf-tcpm-initcwnd
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document proposes an increase in the permitted TCP initial window (IW) from between 2 and 4 segments, as specified in RFC 3390, to 10 segments. It discusses the motivation behind the increase, the advantages and disadvantages of the higher initial window, and presents results from several large scale experiments showing that the higher initial window improves the overall performance of many web services without risking congestion collapse. Finally, it outlines a list of concerns to be addressed in future tests.


Jerry Chu (
Nandita Dukkipati (
Yuchung Cheng (
Matt Mathis (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)