Internet Engineering Task Force

TCP Maintenance and Minor Extensions (tcpm)

Last Modified: 2009-10-13

Additional information is available at tools.ietf.org/wg/tcpm

Chair(s):

Transport Area Director(s):

Transport Area Advisor:

Lars Eggert <lars.eggert@nokia.com>

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
IESG.

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 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
issues brought on by spoofed TCP segments using a
challenge-response scheme to reduce the probabilities of a
connection being impacted. Finally, the WG will produce a
document outlining the potential impact of using ICMP messages
to attack TCP streams.

* 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.

* The WG is writing an informational document that discusses
commonly used, but not documented ways to combat SYN flooding
attacks.

* The WG is updating RFC 2581 to fix some minor specification
problems and move it along the standards track.

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
Done		Submit overview of spoofing attacks against TCP to IESG for publication as an Informational RFC
Done		Submit User TimeOut option document to the IESG for publication as a Proposed Standard RFC
Done		Submit SYN flooding document to the IESG for publication as an Informational RFC
Done		Submit soft errors document to the IESG for publication as an Informational RFC
Mar 2009		Submit In-Window Attack draft to IESG for publication as a Proposed Standard RFC
Done		Submit ECN-SYN document to the IESG for publication as a Proposed Standard RFC
Done		Submit revision of RFC 2581 to the IESG for publication as a Draft Standard
Apr 2009		Submit TCP Authentication Option document to the IESG for Proposed Standard RFC
Jul 2009		Submit ICMP attack document to the IESG for publication as an Informational RFC
Jul 2009		Submit TCP Early-Retransmit document to the IESG for Experimental RFC
Jul 2009		Submit update to RFC 1323 to the IESG for Proposed Standard RFC
Jul 2009		Submit MSS text revision originally from RFC 1323 appendix to the IESG for Proposed Standard RFC
Jan 2010		Submit TCP Urgent Pointer draft to IESG for publication as a Proposed Standard RFC
Aug 2010		Submit document on security hardening of TCP implementations to the IESG for publication as a Best Current Practices RFC
Oct 2010		Submit document on the use of SACK data to trigger loss recovery to the IESG for Proposed Standard
Oct 2010		Submit document on mitigation of 'Long Connectivity Disruptions' to the IESG for Experimental

Internet-Drafts:

Improving TCP's Robustness to Blind In-Window Attacks (45688 bytes)
ICMP attacks against TCP (90777 bytes)
The TCP Authentication Option (102150 bytes)
Early Retransmit for TCP and SCTP (33183 bytes)
TCP Options and MSS (5495 bytes)
On the implementation of the TCP urgent mechanism (26255 bytes)
Security Assessment of the Transmission Control Protocol (TCP) (59093 bytes)
Cryptographic Algorithms for TCP's Authentication Option, TCP-AO (36871 bytes)
Using TCP Selective Acknowledgement (SACK) Information to Determine Duplicate Acknowledgements for Loss Recovery Initiation (36553 bytes)
Making TCP more Robust to Long Connectivity Disruptions (TCP-LCD) (61336 bytes)

Request For Comments:

Forward RTO-Recovery (F-RTO): An Algorithm for Detecting Spurious Retransmission Timeouts with TCP and the Stream Control Transmission Protocol (SCTP) (RFC 4138) (55538 bytes) updated by RFC 5682
Improving the Robustness of TCP to Non-Congestion Events (RFC 4653) (42268 bytes)
A Roadmap for Transmission Control Protocol (TCP) Specification Documents (RFC 4614) (75645 bytes)
Defending TCP Against Spoofing Attacks (RFC 4953) (72756 bytes)
TCP SYN Flooding Attacks and Common Mitigations (RFC 4987) (48753 bytes)
TCP's Reaction to Soft Errors (RFC 5461) (31749 bytes)
TCP User Timeout Option (RFC 5482) (33568 bytes)
Adding Explicit Congestion Notification (ECN) Capability to TCP's SYN/ACK Packets (RFC 5562) (77110 bytes)
TCP Congestion Control (RFC 5681) (44339 bytes) obsoletes RFC 2581
Forward RTO-Recovery (F-RTO): An Algorithm for Detecting Spurious Retransmission Timeouts with TCP (RFC 5682) (47337 bytes) updates RFC 4138