RFC 3540 (rfc3540) - Page 1 of 13


Robust Explicit Congestion Notification (ECN) Signaling with Nonces



Alternative Format: Original Text Document



Network Working Group                                          N. Spring
Request for Comments: 3540                                  D. Wetherall
Category: Experimental                                            D. Ely
                                                University of Washington
                                                               June 2003


             Robust Explicit Congestion Notification (ECN)
                         Signaling with Nonces

Status of this Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

   This note describes the Explicit Congestion Notification (ECN)-nonce,
   an optional addition to ECN that protects against accidental or
   malicious concealment of marked packets from the TCP sender.  It
   improves the robustness of congestion control by preventing receivers
   from exploiting ECN to gain an unfair share of network bandwidth.
   The ECN-nonce uses the two ECN-Capable Transport (ECT)codepoints in
   the ECN field of the IP header, and requires a flag in the TCP
   header.  It is computationally efficient for both routers and hosts.

1.  Introduction

   Statement of Intent

      This specification describes an optional addition to Explicit
      Congestion Notification [RFC 3168] improving its robustness against
      malicious or accidental concealment of marked packets.  It has not
      been deployed widely.  One goal of publication as an Experimental
      RFC is to be prudent, and encourage use and deployment prior to
      publication in the standards track.  Another consideration is to
      give time for firewall developers to recognize and accept the
      pattern presented by the nonce.  It is the intent of the Transport
      Area Working Group to re-submit this specification as an IETF
      Proposed Standard in the future after more experience has been
      gained.




Spring, et. al.               Experimental