TCP Maintenance and Minor Extensions (tcpm)
-------------------------------------------

 Charter
 Last Modified: 2006-08-08

 Current Status: Active Working Group

 Chair(s):
     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 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 

   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. 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Apr 2004 Feb 2006   <draft-ietf-tcpm-tcp-dcr-07.txt>
                Improving the Robustness of TCP to Non-Congestion Events 

Apr 2004 Jun 2006   <draft-ietf-tcpm-tcpsecure-05.txt>
                Improving TCP's Robustness to Blind In-Window Attacks 

Oct 2004 Feb 2006   <draft-ietf-tcpm-tcp-roadmap-06.txt>
                A Roadmap for TCP Specification Documents 

Feb 2005 May 2006   <draft-ietf-tcpm-tcp-antispoof-04.txt>
                Defending TCP Against Spoofing Attacks 

May 2005 Jul 2006   <draft-ietf-tcpm-tcp-uto-03.txt>
                TCP User Timeout Option 

Jan 2006 Jun 2006   <draft-ietf-tcpm-rfc2581bis-01.txt>
                TCP Congestion Control 

Feb 2006 Aug 2006   <draft-ietf-tcpm-tcp-soft-errors-01.txt>
                TCP's Reaction to Soft Errors 

Jul 2006 Jul 2006   <draft-ietf-tcpm-syn-flood-00.txt>
                TCP SYN Flooding Attacks and Common Mitigations 

 Request For Comments:

  RFC   Stat Published     Title
------- -- ----------- ------------------------------------
RFC4138 E    Aug 2005    Forward RTO-Recovery (F-RTO): An Algorithm for Detecting 
                       Spurious Retransmission Timeouts with TCP and the Stream 
                       Control Transmission Protocol (SCTP)