Behavior Engineering for Hindrance Avoidance (behave) ----------------------------------------------------- Charter Last Modified: 2007-10-05 Current Status: Active Working Group Chair(s): Dan Wing Transport Area Director(s): Magnus Westerlund Lars Eggert Transport Area Advisor: Magnus Westerlund Mailing Lists: General Discussion:behave@ietf.org To Subscribe: behave-request@ietf.org In Body: In Body: subscribe Archive: http://www1.ietf.org/mail-archive/web/behave/current/index.html Description of Working Group: Given the current near-universal deployment of NATs (Network Address Translators) in the public Internet, the lack of standards for NAT behavior has given rise to a crisis. While it is widely acknowledged that NATs create problems for numerous Internet applications, our inability to describe precisely what a NAT is or how it behaves leaves us few solutions for compensating for the presence of NATs. The behavior of NATs varies dramatically 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 interactive applications such as multiuser games and interactive multimedia. NATs continue to proliferate and have seen an increasing rate of deployment. IPv6 deployments can eliminate this problem, but there is a significant interim period in which applications will need to work both in IPv4 NAT environments and with the IPv6 to IPv4 transition mechanisms. This working group proposes to generate requirements documents and best current practices to enable NATs to function in as deterministic a fashion as possible. It will consider what is broken by these devices and document approaches for characterizing and testing them. The NAT behavior practices will be application independent. The group will also advise on how to develop applications that discover and reliably function in environments with NATs that follow the best current practices identified by this working group. This will include the development of protocol-independent toolkits usable by application protocols for NAT traversal. This will include a revision of RFC 3489 for NAT binding discovery and a relay protocol that focuses on security. The work will be done with the goal of encouraging eventual migration to IPv6 and compliance with the UNSAF [RFC 3424] considerations. It will not encourage the proliferation of NATs. The behavior that will be considered includes IP fragmentation and parameters that impact ICMP, UDP, TCP, IGMP, MLD, and multicast. The proposed WG will coordinate with v6ops, midcom and nsis. The work is largely limited to examining various approaches that are already in use today and providing suggestions about which ones are likely to work best in the internet architecture. Goals and Milestones: Done Submit BCP that defines unicast UDP behavioral requirements for NATs to IESG Done Submit a BCP that defines TCP behavioral requireents for NATs to IESG Done Submit IPv6 relay protocol 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 Oct 2007 Submit revision of RFC 3489 to IESG behavioral requirements for NATs to IESG Dec 2007 Submit standards-track IPv6 relay protocol Dec 2007 Submit standards-track relay protocol Jan 2008 Submit experimental document that describes how an application can determine the type of NAT it is behind Jan 2008 Close WG or recharter Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Oct 2004 Oct 2007 Session Traversal Utilities for (NAT) (STUN) May 2005 Nov 2007 IP Multicast Requirements for a Network Address (and port) Translator (NAT) Feb 2006 Apr 2007 NAT Behavioral Requirements for TCP Mar 2006 Jul 2007 Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN) Mar 2006 Jul 2007 Extension to the Simple Traversal Underneath NAT (STUN) Relay Usage for IPv4/IPv6 Transition May 2006 Oct 2007 NAT Behavioral Requirements for ICMP protocol Oct 2006 Oct 2007 State of Peer-to-Peer(P2P) Communication Across Network Address Translators(NATs) Feb 2007 Jul 2007 NAT Behavior Discovery Using STUN Request For Comments: RFC Stat Published Title ------- -- ----------- ------------------------------------ RFC4787BCP Jan 2007 Network Address Translation (NAT) Behavioral Requirements for Unicast UDP