Behavior Engineering for Hindrance Avoidance (behave)

Last Modified: 2010-09-02

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

Chair(s):

Transport Area Director(s):

Transport Area Advisor:

Mailing Lists:

General Discussion: behave@ietf.org
To Subscribe: behave-request@ietf.org
In Body: In Body: subscribe
Archive: http://www.ietf.org/mail-archive/web/behave

Description of Working Group:

The working group creates documents to enable NATs to function in as
deterministic a fashion as possible.

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.

BEHAVE will adopt additional work items to finish four scenarios:
An IPv6 network to IPv4 Internet, IPv6 Internet to an IPv4 network,
An IPv6 network to an IPv4 network, and An IPv4 network to an
IPv6 network.  These additional work items include suggestions to
application developers to improve application interactions with
those translation scenarios.

The following scenario remains in scope for discussion, and new
milestones can be created to address this scenario:

* An IPv4 application running on an IPv6-only connected host to the
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 embedded
in the IPv4 host.

The following scenarios remain in scope for discussion, but creating
new milestones will require re-chartering:

* 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.

* 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.

* multicast translation, including control traffic (IGMP and MLD),
Single Source Multicast (SSM) and Any Source Multicast (ASM).

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 parts of ICMP that can be translated are also required to work
across a translation solution.  Additional protocols directly on top of
IP may be supported. Translation mechanisms must handle IP
fragmentation.

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.

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 requireents 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
Done  Determine relative prioritization of the four translation cases. Documented in IETF74 minutes.
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. Documented in IETF74 minutes.
Done  Submit to IESG: relaying of a TCP bytestream (std)
Done  Submit to IESG: relay protocol (std)
Done  Submit to IESG: TURN-URI document (std)
Done  Submit to IESG: IPv6 relay protocol (std)
Done  Submit to IESG: framework for IPv6/IPv4 translation (info)
Done  Submit to IESG: stateless IPv6/IPv4 translation (std)
Done  Submit to IESG: stateful IPv6/IPv4 translation (std)
Done  Submit to IESG: DNS rewriting for IPv6/IPv4 translation (std)
Done  Submit to IESG: IPv6 prefix for IPv6/IPv4 translator (std)
Done  Determine need and scope of multicast 6/4 translation
Oct 2010  Submit to IESG: FTP ALG for IPv6/IPv4 translation (std)
Dec 2010  Submit to IESG: large scale NAT requirements (BCP)
Feb 2011  Submit to IESG: Analysis of NAT-PT considerations with IPv6/IPv4 translation (info)
Apr 2011  Submit to IESG: avoiding NAT64 with dual-stack host for local networks (std)
Apr 2011  Submit to IESG: SCTP NAT behavior (BCP)
Apr 2011  Submit to IESG: NAT64 load balancing (std/info)
Apr 2011  Submit to IESG: host-based NAT46 translation for IPv4-only applications to access IPv6-only servers (std)

Internet-Drafts:

Traversal Using Relays around NAT (TURN) Extension for IPv6 (28761 bytes)
Stream Control Transmission Protocol (SCTP) Network Address Translation (52288 bytes)
IP/ICMP Translation Algorithm (79532 bytes)
DNS64: DNS extensions for Network Address Translation from IPv6 Clients to IPv4 Servers (76045 bytes)
Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers (107656 bytes)
Framework for IPv4/IPv6 Translation (70491 bytes)
An FTP ALG for IPv6-to-IPv4 translation (37697 bytes)
Dual Stack Hosts Using "Bump-in-the-Host" (BIH) (44754 bytes)
Common requirements for IP address sharing schemes (25237 bytes)
Analysis of 64 Translation (32685 bytes)

Request For Comments:

Network Address Translation (NAT) Behavioral Requirements for Unicast UDP (RFC 4787) (68693 bytes)
IP Multicast Requirements for a Network Address Translator (NAT) and a Network Address Port Translator (NAPT) (RFC 5135) (36528 bytes)
State of Peer-to-Peer(P2P) Communication Across Network Address Translators(NATs) (RFC 5128) (81008 bytes)
NAT Behavioral Requirements for TCP (RFC 5382) (50306 bytes)
Session Traversal Utilities for NAT (STUN) (RFC 5389) (125650 bytes) obsoletes RFC 3489
NAT Behavioral Requirements for ICMP (RFC 5508) (67985 bytes)
Network Address Translation (NAT) Behavioral Requirements for the Datagram Congestion Control Protocol (RFC 5597) (18933 bytes)
Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN) (RFC 5766) (172112 bytes)
Test Vectors for Session Traversal Utilities for NAT (STUN) (RFC 5769) (15407 bytes)
NAT Behavior Discovery Using Session Traversal Utilities for NAT (STUN) (RFC 5780) (67835 bytes)
Traversal Using Relays around NAT (TURN) Resolution Mechanism (RFC 5928) (23993 bytes)
IPv6 Addressing of IPv4/IPv6 Translators (RFC 6052) (41849 bytes) updates RFC 4291
Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations (RFC 6062) (28978 bytes)