Network Working Group M. Petit-Huguenin Internet-Draft 8x8, Inc. Intended status: Standards Track November 20, 2008 Expires: May 24, 2009 Alternative Proposal for Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations draft-petithuguenin-turn-tcp-variant-00 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 other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months 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 24, 2009. Abstract This document proposes an alternative to the Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations [I-D.ietf-behave-turn-tcp] document. Petit-Huguenin Expires May 24, 2009 [Page 1] Internet-Draft TURN TCP November 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Sending a Connect Request . . . . . . . . . . . . . . . . . . . 3 4. Receiving a Connect Request . . . . . . . . . . . . . . . . . . 3 5. Receiving a Connect Response . . . . . . . . . . . . . . . . . 4 6. Sending Data . . . . . . . . . . . . . . . . . . . . . . . . . 4 7. Sending an AdjustWindow Indication . . . . . . . . . . . . . . 4 8. Receiving an AdjustWindow Indication . . . . . . . . . . . . . 4 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 11. Running Code Considerations . . . . . . . . . . . . . . . . . . 4 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 13.1. Normative References . . . . . . . . . . . . . . . . . . . 5 13.2. Informative References . . . . . . . . . . . . . . . . . . 5 Appendix A. Release notes . . . . . . . . . . . . . . . . . . . . 5 A.1. Design Notes . . . . . . . . . . . . . . . . . . . . . . . 5 A.2. TODO List . . . . . . . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 7 Petit-Huguenin Expires May 24, 2009 [Page 2] Internet-Draft TURN TCP November 2008 1. Introduction [I-D.ietf-behave-turn-tcp] proposes to use a different TCP connection between the TURN client and the TURN server for each TCP connection between the TURN server and the peer. This document proposes an alternate solution where only one TCP connection is used between the TURN client and the TURN server but where a window size adjustement algorithm inspired by SSH [RFC4254] is used. The following sections describe only the differences with [I-D.ietf-behave-turn-tcp] 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Sending a Connect Request To initiate a TCP connection to a peer, a TURN client MUST send a Connect request to the TURN server over an existing allocation. The Connect request MUST include a XOR-PEER-ADDRESS attribute containing the IP address and port of the peer to which a connection is desired, a WINDOW-SIZE attribute containing how many bytes of data can be sent to the TURN client without adjusting the window, and a MAX-SIZE attribute containing the maximum size of a ChannelData or Data message can be sent to the TURN client. 4. Receiving a Connect Request When receiving a Connect request, the TURN server MUST establish a TCP connection to the IP address and port contained in the XOR-PEER- ADDRESS attribute. If the connection is successful, the TURN server sends back to the TURN client a Connect response containing a WINDOW- SIZE attribute containing how many bytes of data can be sent to the TURN server without adjusting the window, and a MAX-SIZE attribute containing the maximum size of a ChannelData or Send message that can be sent to the TURN server. The TURN server associates the current window size in the WINDOW-SIZE attribute to the TCP connection to the peer. Petit-Huguenin Expires May 24, 2009 [Page 3] Internet-Draft TURN TCP November 2008 5. Receiving a Connect Response The TURN server associates the current window size in the WINDOW-SIZE attribute to the IP address and port of the peer TCP connection. 6. Sending Data When sending data in a ChannelData, Send or Data message, the sender decreases the current window size by the number of bytes sent. The sender MUST stop when the current window size is smaller than the size of the data to send. 7. Sending an AdjustWindow Indication When ready to receive more data, the TURN server or client sends an AdjustWindow indication to the other side. The AdjustWindow indication MUST contain either a XOR-PEER-ADDRESS or a CHANNEL-NUMBER attribute indentifying the TCP connection to the peer. The AdjustWindow indication MUST contain a ADD-SIZE attribute containing the value to add to the current window size. 8. Receiving an AdjustWindow Indication When receiving an AdjustWindow indication, a TURN client or server uses the XOR-PEER-ADDRESS or CHANNEL-NUMBER to find the current window size associated to the TCP connection to the peer. The TURN client or server then increases the window size by the value in the ADD-SIZE attribute. 9. Security Considerations TBD 10. IANA Considerations TBD 11. Running Code Considerations TBD Petit-Huguenin Expires May 24, 2009 [Page 4] Internet-Draft TURN TCP November 2008 12. Acknowledgements Adam Roach proposed to use the SSH algorithm at the microphone in the BEHAVE session in Minneapolis. This document was written with the xml2rfc tool described in [RFC2629]. 13. References 13.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4254] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH) Connection Protocol", RFC 4254, January 2006. [I-D.ietf-behave-turn-tcp] Rosenberg, J. and R. Mahy, "Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations", draft-ietf-behave-turn-tcp-00 (work in progress), November 2007. 13.2. Informative References [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. Appendix A. Release notes This section must be removed before publication as an RFC. A.1. Design Notes (Empty) A.2. TODO List (Empty) Petit-Huguenin Expires May 24, 2009 [Page 5] Internet-Draft TURN TCP November 2008 Author's Address Marc Petit-Huguenin 8x8, Inc. 3151 Jay Street Santa Clara, CA 95054 US Phone: +1 408 654 0875 Email: marc@8x8.com Petit-Huguenin Expires May 24, 2009 [Page 6] Internet-Draft TURN TCP November 2008 Full Copyright Statement 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. 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Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an 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. Petit-Huguenin Expires May 24, 2009 [Page 7]