2.8.10 TCP Maintenance and Minor Extensions (tcpm)

NOTE: This charter is a snapshot of the 67th IETF Meeting in San Diego, California USA. It may now be out-of-date.

Last Modified: 2006-08-08


Ted Faber <faber@isi.edu>
Mark Allman <mallman@icir.org>

Transport Area Director(s):

Magnus Westerlund <magnus.westerlund@ericsson.com>
Lars Eggert <lars.eggert@netlab.nec.de>

Transport Area Advisor:

Lars Eggert <lars.eggert@netlab.nec.de>

Mailing Lists:

General Discussion: tcpm@ietf.org
To Subscribe: https://www.ietf.org/mailman/listinfo/tcpm
Archive: http://www.ietf.org/mail-archive/web/tcpm/index.html

Description of Working Group:

TCP is currently the Internet's predominant transport protocol.
To maintain TCP's utility the IETF has regularly updated both
the protocol itself and the congestion control algorithms
implemented by the protocol that are crucial for the stability
of the Internet. These changes reflect our evolving
understanding of transport protocols, congestion control and new
needs presented by an ever-changing network. The TCPM WG will
provide a venue within the IETF to work on these issues. The WG
will serve several purposes:

* The WG will mostly focus on maintenance issues (e.g., bug
fixes) and modest changes to the protocol and algorithms
that maintain TCP's utility.

* The WG will be a venue for moving current TCP specifications
along the standards track (as community energy is available
for such efforts).

* The WG will write a document that outlines "what is TCP".
This document will be a roadmap of sorts to the various TCP
specifications in the RFC series.

TCPM will take a subset of the work which has been conducted in
the Transport Area WG over the past several years.
Specifically, some of the WG's initial work will be moved from
the Transport Area WG (tsvwg).

TCPM is expected to be the working group within the IETF to
handle TCP changes. Proposals for additional TCP work items
should be brought up within the working group. While
fundamental changes to TCP or its congestion control algorithms
(e.g., departure from loss-based congestion control) should be
brought through TCPM, it is expected that such large changes
will ultimately be handled by the Transport Area WG (tsvwg).
All additional work items for TCPM will, naturally, require the
approval of the Transport Services Area Area Directors and the

TCP's congestion control algorithms are the model followed by
alternate transports (e.g., SCTP and (in some cases) DCCP). In
addition, the IETF has recently worked on several documents
about algorithms that are specified for multiple protocols
(e.g., TCP and SCTP) in the same document. Which WG shepherds
such documents in the future will determined on a case-by-case
basis. In any case, the TCPM WG will remain in close contact
with other relevant WGs working on these protocols to ensure
openness and stringent review from all angles.

Specific Goals:

* A document specifying a way to share the local "User TimeOut"
value with the peer such that TCP connections can withstand long
periods of disconnection.

* The WG is working on an experimental technique to add robustness
to TCP against packet reordering having a negative impact on

* The WG is coming to grips with how to deal with spoofed segments
that can tear down connections, cause data corruption or
performance problems. To this end the WG is generating an
overview document as well as a scheme that mitigates some of the
spoofed segment issues using a challenge-response scheme to
reduce the probabilities of a connection being impacted.

* The WG is writing an informational document about the ways in
which TCPs can handle ICMP "soft errors".

* The WG is updating the specification for Explicit Congestion
Notification to allow for the use of ECN during part of TCP's
three-way handshake to aid performance for short transfers.

Goals and Milestones:

Done  Submit FRTO draft to IESG for publication as an Experimental RFC
Done  Submit TCP Roadmap document to IESG for publication as a Best Current Practices RFC
Done  Submit NCR Reordering Mitigation draft to the IESG for publication as an Experimental RFC
Sep 2006  Submit overview of spoofing attacks against TCP to IESG for publication as an Informational RFC.
Oct 2006  Submit In-Window Attack draft to IESG for publication as a Proposed Standard RFC.
Oct 2006  Submit revision of RFC 2581 to the IESG for publication as a Draft Standard.
Nov 2006  Submit User TimeOut option document to the IESG for publication as a Proposed Standard RFC.
Nov 2006  Submit ECN-SYN document to the IESG for publication as a Proposed Standard RFC.
Jan 2007  Submit SYN flooding document to the IESG for publication as an Informational RFC.
Jan 2007  Submit soft errors document to the IESG for publication as an Informational RFC.
Jan 2007  Submit ICMP attack document to the IESG for publication as an Informational RFC.


  • draft-ietf-tcpm-tcpsecure-05.txt
  • draft-ietf-tcpm-tcp-antispoof-05.txt
  • draft-ietf-tcpm-tcp-uto-04.txt
  • draft-ietf-tcpm-ecnsyn-01.txt
  • draft-ietf-tcpm-rfc2581bis-01.txt
  • draft-ietf-tcpm-tcp-soft-errors-02.txt
  • draft-ietf-tcpm-icmp-attacks-01.txt
  • draft-ietf-tcpm-syn-flood-00.txt

    Request For Comments:

    RFC4138 E Forward RTO-Recovery (F-RTO): An Algorithm for Detecting Spurious Retransmission Timeouts with TCP and the Stream Control Transmission Protocol (SCTP)
    RFC4614 I A Roadmap for Transmission Control Protocol (TCP) Specification Documents
    RFC4653 E Improving the Robustness of TCP to Non-Congestion Events

    Meeting Minutes


    User Timeout
    UTO (Pdf)
    ICMP attacks
    ICMP Attacks (pdf)