TCP Maintenance and Minor Extensions (tcpm) ------------------------------------------- Charter Last Modified: 2006-08-08 Current Status: Active Working Group Chair(s): Ted Faber Mark Allman Transport Area Director(s): Magnus Westerlund Lars Eggert Transport Area Advisor: Lars Eggert 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 ------ ------- -------------------------------------------- Apr 2004 Jul 2007 Improving TCP's Robustness to Blind In-Window Attacks May 2005 Jun 2007 TCP User Timeout Option Jan 2006 Jul 2007 Adding Explicit Congestion Notification (ECN) Capability to TCP's SYN/ACK Packets Feb 2006 Jun 2007 TCP's Reaction to Soft Errors Feb 2006 May 2007 ICMP attacks against TCP Jul 2006 May 2007 TCP SYN Flooding Attacks and Common Mitigations Jun 2007 Jun 2007 Forward RTO-Recovery (F-RTO): An Algorithm for Detecting Spurious Retransmission Timeouts with TCP 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