Subject: [AAA-DOCTORS] FW: WG Review: Recharter of Behavior Engineering for Hindrance Avoidance (behave)

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Tue, 9 Jun 2009 18:18:41 +0200

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
IESG Secretary
Sent: Tuesday, June 09, 2009 7:15 PM
To: [email-masked]
Subject: WG Review: Recharter of Behavior Engineering for Hindrance
Avoidance (behave) 

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 ([email-masked]) 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 <[email-masked]>
Dave Thaler <[email-masked]>

Transport Area Director(s):
Magnus Westerlund <[email-masked]> Lars Eggert
<[email-masked]>

Transport Area Advisor:
Magnus Westerlund <[email-masked]>

Mailing Lists:
General Discussion: [email-masked]
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