Network Working Group O. Gsenger Internet-Draft March 2007 Expires: September 2, 2007 Anycast stream relaying draft-gsenger-anycast-relay-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 September 2, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Gsenger Expires September 2, 2007 [Page 1] Internet-Draft Anycast stream relaying March 2007 Abstract The anycast tunneling (anytun) protocol defines a protocol used for communication between unicast clients and anycast servers. It can be used for tunneling information between 2 clients over the servers or in relay mode to transmit data form the client over the servers to a third party not using the protocol and vice versa. Gsenger Expires September 2, 2007 [Page 2] Internet-Draft Anycast stream relaying March 2007 1. Introduction anytun defines a Host Anycast Service as defined in rfc1546. It can be used to build high scalable and redundant tunnel services. It supports both UDP and TCP connections. Additionally to the possibility of establashing an unicast TCP connection over an anycast address as suggested in rfc1546, it supports real anycast TCP connections with state syncronisation and heuristic state forecast. It also has a relay mode, that makes it possible, that only one of the connection endpoints has to use the anytun protocol. This can be used to make connections through Firewalls or behind a NAT Router RFC3068 [1] DTD. 1.1. Operation modes 1.1.1. Tunnel modes 1.1.1.1. Tunneling Mode An example of anytun used in tunnel mode ----------- ----------- | RTP | ---------- | RTP | ----------- -> |server 1| -> ----------- | UDP | ---------- | UDP | ----------- ----------- ----- | IPv6 | ---------- | IPv6 | ----- | | -> ----------- -> |server 2| -> ----------- -> | | ----- | anytun | ---------- | anytun | ----- ##### ----------- ----------- ##### | UDP | ---------- | UDP | client 1 ----------- -> |server 3| -> ----------- client 2 | IPv4 | ---------- | IPv4 | ----------- ----------- | ... | anycast | ... | Figure 1 In tunneling mode the payload of the anytun packet is transmitted from one unicast host to the anycast server. This server makes a routing descision based on the underlying protocol and transmits a new anytun package to one or more clients depending on the routing descition. The server MAY also route the packet to a directly connected network or a service running on the server, but please note, that this is only usefull for anycast host services like DNS and that the services HAVE TO be running on all servers in order to work. Gsenger Expires September 2, 2007 [Page 3] Internet-Draft Anycast stream relaying March 2007 1.1.1.2. Open tunnel mode In open tunnel mode only one of two clients talking to each other over the servers MUST use the anytun protocol. When a client using the anytun protocol wants to tunnel data, it is building a connection to the anycast servers using the anytun protocol. The anycast servers relay the encapsulated packages directly to the destination without using the anytun protocol. The source address of the datagramm HAS TO be changed to the anycast address of the server. The anytun servers act like a source NAT router, therefor for the destination it saems that it is talking to the client directly. 1.1.1.3. relay mode In relay mode the anycast serveres directly repaet the packetes of clients, only the source and destination addresses are changed. The anytun protocol is only used for controll messages, but not fr encapsulation. 1.1.2. Transport modes 1.1.2.1. anycast udp mode 1.1.2.2. unicast tcp with anycast initialisation 1.1.2.3. full anycast tcp 1.1.2.3.1. keep alive message request Most NAT routers need a tcp connection to transmit some packets once in while to stay open. In full anycast tcp mode anytun hast to predict the tcp state including the sequence number. Synconisation of the sequence number would be to much overhead, so a keep alive intervall is agreed. This interval is used to calculate the sequemce number. Gsenger Expires September 2, 2007 [Page 4] Internet-Draft Anycast stream relaying March 2007 2. Protocol specification 2.1. Header format Gsenger Expires September 2, 2007 [Page 5] Internet-Draft Anycast stream relaying March 2007 Appendix A. The appan Gsenger Expires September 2, 2007 [Page 6] Internet-Draft Anycast stream relaying March 2007 3. References [1] Huitema, C., "An Anycast Prefix for 6to4 Relay Routers", RFC 3068, June 2001. Gsenger Expires September 2, 2007 [Page 7] Internet-Draft Anycast stream relaying March 2007 Author's Address Othmar Gsenger Sporgasse 6 Graz 8010 AT Phone: Email: otti@wirdorange.org URI: http://anytun.org/ Gsenger Expires September 2, 2007 [Page 8] Internet-Draft Anycast stream relaying March 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Gsenger Expires September 2, 2007 [Page 9]