A modified charter has been submitted for the Behavior Engineering for Hindrance Avoidance (behave) working group in the Transport Area of the IETF. The IESG has not made any determination as yet. The modified charter is provided below for informational purposes only. Please send your comments to the IESG mailing list (iesg@ietf.org) by Tuesday, June 16, 2009. Behavior Engineering for Hindrance Avoidance (behave) ----------------------------------------------------- Last Modified: 2009-05-27 Current Status: Active Working Group Chair(s): Dan Wing <dwing@cisco.com> Dave Thaler <dthaler@microsoft.com> Transport Area Director(s): Magnus Westerlund <magnus.westerlund@ericsson.com> Lars Eggert <lars.eggert@nokia.com> Transport Area Advisor: Magnus Westerlund <magnus.westerlund@ericsson.com> Mailing Lists: General Discussion: behave@ietf.org To Subscribe: https://www.ietf.org/mailman/listinfo/behave Archive: http://www.ietf.org/mail-archive/web/behave Description of Working Group: The behavior of NATs varies from one implementation to another. As a result it is very difficult for applications to predict or discover the behavior of these devices. Predicting and/or discovering the behavior of NATs is important for designing application protocols and NAT traversal techniques that work reliably in existing networks. This situation is especially problematic for end- to-end applications where one or both end-points are behind a NAT, such as multiuser games, interactive multimedia and P2P download. The working group documents best current practices to enable NATs to function in as deterministic a fashion as possible. The NAT behavior practices will be application independent. This has already completed for UDP, TCP, DCCP, Multicast and ICMP. It continues with SCTP and any additional protocol deemed necessary to handle. The WG has documented approaches for characterizing and testing NAT devices. BEHAVE will develop protocol-independent toolkits usable by application protocols for NAT traversal. The WG has already produced an update of the binding discovery protocol STUN. It will now produce a relay protocol that focuses on security that is usable with both IPv4 and IPv6, and capable of relaying between the two IP versions. The goal of this work is to encourage migration to IPv6. To support deployments where communicating hosts require using different address families (IPv4 or IPv6), address family translation is needed to establish communication. In BEHAVE's specification work on this topic it will coordinate with the V6ops WG on requirements and operational considerations. "An IPv4 network" or "an IPv6 network" in the descriptions below refer to a network with a clearly identifiable administrative domain (e.g., an enterprise campus network, a mobile operator's cellular network, a residential subscriber network, etc.). It will also be that network that deploys the necessary equipment for translation. The BEHAVE WG will design solutions for the following six translation scenarios; other scenarios are out of scope: 1. An IPv6 network to IPv4 Internet, i.e. perform translation between IPv4 and IPv6 for packets in uni- or bi-directional flows that are initiated from an IPv6 host towards an IPv4 host. The translator function is intended to service a specific IPv6 network of arbitary size. Port translation is necessary on the IPv4 side for efficient IPv4 address usage. 2. IPv6 Internet to an IPv4 network, i.e. perform translation between IPv4 and IPv6 for packets in uni- or bi-directional flows that are initiated from an IPv6 host towards an IPv4 host. The translator function services is intended to service a specific IPv4 network using either private or public IPv4 addresses. Because this scenario has different constraints compared to (1), e.g. the IPv4 hosts that are to be reachable over IPv6 can be enumerated. The WG should attempt to design a simpler solution with less impact on applications. 3. An IPv4 network to IPv6 Internet, i.e. perform translation between IPv4 and IPv6 for packets in uni- or bi-directional flows that are initiated from an IPv4 host towards an IPv6 host. The translator function is intended to service a specific IPv4 network using either public or private IPv4 address space. 4. IPv4 Internet to an IPv6 network, i.e. perform translation between IPv4 and IPv6 for packets in uni- or bi-directional flows that are initiated from an IPv4 host towards an IPv6 host. The translator function is intended to service a specific IPv6 network where selected IPv6 hosts and services are to be reachable. 5. An IPv6 network to an IPv4 network, i.e., perform translation between IPv6 and IPv4 for packets in uni- or bi-directional flows that are initiated from an IPv6 host towards an IPv4 host. The translation function is intended to service a specific IPv6 network of arbitrary size and a specific IPv4 network of arbitrary size (neither of which are the Internet). 6. An IPv4 network to an IPv6 network, i.e., perform translation between IPv4 and IPv6 for packets in uni- or bi-directional flows that are initiated from an IPv4 host towards an IPv6 host. The translation function is intended to service a specific IPv6 network of arbitrary size and a specific IPv4 network of arbitrary size (neither of which are the Internet). All translation solutions shall be capable of handling flows using TCP, UDP, DCCP, and SCTP, unless they prevent a timely completion of the work item. The fundamental parts of ICMP are also required to work. Additional protocols directly on top of IP may be supported. Translation mechanisms must handle IP fragmentation. The translators should support multicast traffic and its control traffic (IGMP and MLD) across them, both Single Source Multicast (SSM) and Any Source Multicast (ASM). However, the WG may determine that it becomes too complex or too difficult to realize with maintained functionality, for some or all cases of multicast functionality. Translation mechanisms cannot transparently support protocols that embed network addresses within their protocol messages without application level gateways (ALGs). Because ALGs have security issues (like blocking usage of TLS), are error prone and brittle, and hinder application development, the usage of ALGs in the defined translators should be avoided. Instead application developers will need to be aware and use mechanisms that handle the address family translation. ALGs may be considered only for the most crucial of legacy applications. DNS is a crucial part in making a large number of applications work across a translator. Thus the solution to the above translation cases shall include recommendations for DNS. If additional DNS functionality is needed, it may be developed. Any DNS extensions must be developed together with the DNSEXT WG, including issuing a joint WG last call for any documents. The WG needs to determine the best method for providing address space to a translator in the different deployment cases and documenting the pros and cons of the suggested approaches. The WG is to seek input from the Routing, Operations and Internet areas. Solutions may solve more than one of the cases, however timely delivery is more important than a unified solution. Goals and Milestones: Done Submit BCP that defines unicast UDP behavioral requirements for NATs to IESG Done Submit a BCP that defines TCP behavioral requirements for NATs to IESG Done Submit a BCP that defines ICMP behavioral requirements for NATs to IESG Done Submit informational that discusses current NAT traversal techniques used by applications Done Submit BCP that defines multicast UDP Done Submit revision of RFC 3489 to IESG behavioral requirements for NATs to IESG Done Submit informational document for rfc3489bis test vectors Done Submit experimental document that describes how an application can determine the type of NAT it is behind Done Submit BCP document for DCCP NAT behavior Jun 2009 Submit BCP document for SCTP NAT behavior Done Submit standards-track relay protocol Done Determine relative prioritization of the four translation cases. Sep 2009 Submit standards-track document for relaying of a TCP bytestream Jun 2009 Submit standard-track document of an IPv6 relay protocol to IESG Done Determine what solutions(s) and components are needed to solve each of the four cases. Create new milestones for the solution(s) and the components. Jul 2009 Submit standards-track TURN-URI document Sep 2009 Submit informational for framework for IPv6/IPv4 translation document Sep 2009 Submit standards-track stateless IPv6/IPv4 translation document Sep 2009 Submit standards-track stateful IPv6/IPv4 translation document Sep 2009 Submit standards-track DNS rewriting for IPv6/IPv4 translation document Nov 2009 Submit standards-track FTP ALG for IPv6/IPv4 translation document Nov 2009 Submit standards-track IPv6 prefix for IPv6/IPv4 translator document Mar 2010 Submit BCP large scale NAT requirements document _______________________________________________ IETF-Announce@ietf.org https://www.ietf.org/mailman/listinfo/ietf-announce
