Behavior Engineering for Hindrance Avoidance (behave)

Last Modified: 2006-07-11

Additional information is available at tools.ietf.org/wg/behave

Chair(s):

  • Dan Wing <dwing@cisco.com>

    Transport Area Director(s):

  • Magnus Westerlund <magnus.westerlund@ericsson.com>
  • Lars Eggert <lars.eggert@netlab.nec.de>

    Transport Area Advisor:

  • Magnus Westerlund <magnus.westerlund@ericsson.com>

    Mailing Lists:

    General Discussion: ietf-behave@list.sipfoundry.org
    To Subscribe: ietf-behave-request@list.sipfoundry.org
    In Body: with subscribe in body
    Archive: http://list.sipfoundry.org/archive/ietf-behave

    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
    Aug 2006  Submit revision of RFC 3489 to IESG
    Sep 2006  Submit BCP that defines multicast UDP behavioral requirements for NATs to IESG
    Oct 2006  Submit relay protocol to IESG
    Oct 2006  Submit IPv6 relay protocol to IESG
    Dec 2006  Submit a BCP that discusses protocol design techniques for using the existing set of NAT traversal approaches to IESG
    Mar 2007  Submit a BCP that defines TCP behavioral requirements for NATs to IESG
    Mar 2007  Submit a BCP that defines ICMP behavioral requirements for NATs to IESG
    Apr 2007  Close WG or recharter

    Internet-Drafts:

    Simple Traversal Underneath Network Address Translators (NAT) (STUN) (154664 bytes)
    NAT Behavioral Requirements for Unicast UDP (69680 bytes)
    Multicast Requirements for a Network Address Port Translator (NAPT) (14493 bytes)
    NAT Behavioral Requirements for TCP (46432 bytes)
    Obtaining Relay Addresses from Simple Traversal of UDP Through NAT (STUN) (125970 bytes)
    Traversal Using Relay NAT (TURN) Extension for IPv4/IPv6 transition (15297 bytes)
    NAT Behavioral Requirements for ICMP protocol (40467 bytes)

    No Request For Comments

    IETF Secretariat - Please send questions, comments, and/or suggestions to ietf-web@ietf.org.

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