--- 1/draft-ietf-tcpm-tcp-uto-08.txt 2008-06-13 15:12:23.000000000 +0200 +++ 2/draft-ietf-tcpm-tcp-uto-09.txt 2008-06-13 15:12:23.000000000 +0200 @@ -1,19 +1,19 @@ TCP Maintenance and Minor L. Eggert Extensions (tcpm) Nokia Internet-Draft F. Gont Intended status: Standards Track UTN/FRH -Expires: May 22, 2008 November 19, 2007 +Expires: December 15, 2008 June 13, 2008 TCP User Timeout Option - draft-ietf-tcpm-tcp-uto-08 + draft-ietf-tcpm-tcp-uto-09 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -24,25 +24,21 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on May 22, 2008. - -Copyright Notice - - Copyright (C) The IETF Trust (2007). + This Internet-Draft will expire on December 15, 2008. Abstract The TCP user timeout controls how long transmitted data may remain unacknowledged before a connection is forcefully closed. It is a local, per-connection parameter. This document specifies a new TCP option - the TCP User Timeout Option - that allows one end of a TCP connection to advertise its current user timeout value. This information provides advice to the other end of the TCP connection to adapt its user timeout accordingly. Increasing the user timeouts on @@ -63,21 +59,21 @@ 3.4. Reserved Option Values . . . . . . . . . . . . . . . . . . 10 4. Interoperability Issues . . . . . . . . . . . . . . . . . . . 10 4.1. Middleboxes . . . . . . . . . . . . . . . . . . . . . . . 10 4.2. TCP Keep-Alives . . . . . . . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. Normative References . . . . . . . . . . . . . . . . . . . 12 8.2. Informative References . . . . . . . . . . . . . . . . . . 13 - Appendix A. Document Revision History . . . . . . . . . . . . . . 14 + Appendix A. Document Revision History . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Intellectual Property and Copyright Statements . . . . . . . . . . 17 1. Introduction The Transmission Control Protocol (TCP) specification [RFC0793] defines a local, per-connection "user timeout" parameter that specifies the maximum amount of time that transmitted data may remain unacknowledged before TCP will forcefully close the corresponding connection. Applications can set and change this parameter with OPEN @@ -170,21 +166,21 @@ CHANGEABLE (Boolean) Flag that controls whether USER_TIMEOUT (TCP's USER TIMEOUT parameter) may be changed based on an UTO option received from the other end of the connection. Defaults to true and becomes false when an application explicitly sets USER_TIMEOUT. Note that an exchange of UTO options between both ends of a connection is not a binding negotiation. Transmission of a UTO option is a suggestion that the other end consider adapting its user - timeout. This adaptation only happens if the the other end of the + timeout. This adaptation only happens if the other end of the connection has explicitly allowed it (both ENABLED and CHANGEABLE are true). Before opening a connection, an application that wishes to use the UTO option enables its use by setting ENABLED to true. It may choose an appropriate local UTO by explicitly setting ADV_UTO; otherwise, UTO is set to the default USER TIMEOUT value. Finally, the application should determine whether it will allow the local USER TIMEOUT to change based on received UTO options from the other end of a connection. The default is to allow this for connections that do @@ -506,22 +502,21 @@ Note that if TCP needs to close or abort connections with a long TCP User Timeout Option to shed load, these connections are still no worse off than without the option. Finally, upper and lower limits on user timeouts, discussed in Section 3.1, can be an effective tool to limit the impact of these sorts of attacks. 6. IANA Considerations - This section is to be interpreted according to - [I-D.narten-iana-considerations-rfc2434bis]. + This section is to be interpreted according to [RFC5226]. This document does not define any new namespaces. It requests that IANA allocate a new 8-bit TCP option number for the UTO option from the registry maintained at http://www.iana.org/assignments/tcp-parameters. 7. Acknowledgments The following people have improved this document through thoughtful suggestions: Mark Allman, Caitlin Bestler, David Borman, Bob Braden, @@ -529,35 +524,33 @@ Faber, Guillermo Gont, Tom Henderson, Joseph Ishac, Jeremy Harris, Alfred Hoenes, Phil Karn, Michael Kerrisk, Dan Krejsa, Jamshid Mahdavi, Kostas Pentikousis, Juergen Quittek, Anantha Ramaiah, Joe Touch, Stefan Schmid, Simon Schuetz, Tim Shepard and Martin Stiemerling. 8. References 8.1. Normative References - [I-D.narten-iana-considerations-rfc2434bis] - Narten, T. and H. Alvestrand, "Guidelines for Writing an - IANA Considerations Section in RFCs", - draft-narten-iana-considerations-rfc2434bis-08 (work in - progress), October 2007. - [RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, September 1981. [RFC1122] Braden, R., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, October 1989. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. + [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an + IANA Considerations Section in RFCs", BCP 26, RFC 5226, + May 2008. + 8.2. Informative References [I-D.eddy-tcp-mobility] Eddy, W., "Mobility Support For TCP", draft-eddy-tcp-mobility-00 (work in progress), April 2004. [MEDINA] Medina, A., Allman, M., and S. Floyd, "Measuring Interactions Between Transport Protocols and Middleboxes", Proc. 4th ACM SIGCOMM/USENIX Conference on Internet Measurement , October 2004. @@ -583,24 +576,26 @@ [RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common Mitigations", RFC 4987, August 2007. [SOLARIS-MANUAL] Sun Microsystems, "Solaris Tunable Parameters Reference Manual", Part No. 806-7009-10, 2002. Appendix A. Document Revision History [[Note to the RFC Editor: Section to be removed upon publication.]] - +----------+--------------------------------------------------------+ | Revision | Comments | +----------+--------------------------------------------------------+ + | -09 | Resubmission after expiration. Updated reference to | + | | [RFC5226]. | + | | | | -08 | Addressed additional, minor working group last call | | | comments. | | | | | -07 | Addressed working group last call comments. | | | | | -06 | Includes a note on the limited space for TCP options | | | and miscellaneous editorial changes (suggested by | | | Anantha Ramaiah). Includes possible enforcement of | | | per-outgoing-interface limits for the UTO, and | | | miscellaneous editorial changes (suggested by Alfred | @@ -671,21 +666,21 @@ Evaristo Carriego 2644 Haedo, Provincia de Buenos Aires 1706 Argentina Phone: +54 11 4650 8472 Email: fernando@gont.com.ar URI: http://www.gont.com.ar/ Full Copyright Statement - Copyright (C) The IETF Trust (2007). + Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF @@ -708,15 +703,10 @@ attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. - -Acknowledgment - - Funding for the RFC Editor function is provided by the IETF - Administrative Support Activity (IASA).