RFC 2581 (rfc2581) - Page 1 of 14
TCP Congestion Control
Alternative Format: Original Text Document
Network Working Group M. Allman
Request for Comments: 2581 NASA Glenn/Sterling Software
Obsoletes: 2001 V. Paxson
Category: Standards Track ACIRI / ICSI
W. Stevens
Consultant
April 1999
TCP Congestion Control
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
This document defines TCP's four intertwined congestion control
algorithms: slow start, congestion avoidance, fast retransmit, and
fast recovery. In addition, the document specifies how TCP should
begin transmission after a relatively long idle period, as well as
discussing various acknowledgment generation methods.
1. Introduction
This document specifies four TCP [Pos81] congestion control
algorithms: slow start, congestion avoidance, fast retransmit and
fast recovery. These algorithms were devised in [Jac88] and [Jac90].
Their use with TCP is standardized in [Bra89].
This document is an update of [Ste97]. In addition to specifying the
congestion control algorithms, this document specifies what TCP
connections should do after a relatively long idle period, as well as
specifying and clarifying some of the issues pertaining to TCP ACK
generation.
Note that [Ste94] provides examples of these algorithms in action and
[WS95] provides an explanation of the source code for the BSD
implementation of these algorithms.
Allman, et. al. Standards Track