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

 Charter
 Last Modified: 2008-08-21

 Current Status: Active Working Group

 Chair(s):
     Wesley Eddy  <weddy@grc.nasa.gov>
     David Bormann  <david.borman@windriver.com>
     David Borman  <david.borman@windriver.com>

 Transport Area Director(s):
     Magnus Westerlund  <magnus.westerlund@ericsson.com>
     Lars Eggert  <lars.eggert@nokia.com>

 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 working on an experimental technique to add robustness 
to TCP against packet reordering having a negative impact on 
performance. 

* 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. 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Apr 2004 Jul 2008   <draft-ietf-tcpm-tcpsecure-10.txt>
                Improving TCP's Robustness to Blind In-Window Attacks 

May 2005 Jun 2008   <draft-ietf-tcpm-tcp-uto-09.txt>
                TCP User Timeout Option 

Jan 2006 Aug 2008   <draft-ietf-tcpm-ecnsyn-06.txt>
                Adding Explicit Congestion Notification (ECN) Capability to 
                TCP's SYN/ACK Packets 

Jan 2006 Apr 2008   <draft-ietf-tcpm-rfc2581bis-04.txt>
                TCP Congestion Control 

Feb 2006 Apr 2008   <draft-ietf-tcpm-tcp-soft-errors-08.txt>
                TCP's Reaction to Soft Errors 

Jun 2007 Sep 2008   <draft-ietf-tcpm-rfc4138bis-03.txt>
                Forward RTO-Recovery (F-RTO): An Algorithm for Detecting 
                Spurious Retransmission Timeouts with TCP 

Nov 2007 Jul 2008   <draft-ietf-tcpm-tcp-auth-opt-01.txt>
                The TCP Authentication Option 

Aug 2008 Aug 2008   <draft-ietf-tcpm-early-rexmt-00.txt>
                Early Retransmit for TCP and SCTP 

 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) 

RFC4653 E    Aug 2006    Improving the Robustness of TCP to Non-Congestion Events 

RFC4614 I    Sep 2006    A Roadmap for Transmission Control Protocol (TCP) 
                       Specification Documents 

RFC4953 I    Jul 2007    Defending TCP Against Spoofing Attacks 

RFC4987 I    Aug 2007    TCP SYN Flooding Attacks and Common Mitigations