Subject: [MIB-DOCTORS] FW: WG Review: Congestion Exposure (conex)

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Wed, 14 Apr 2010 18:34:30 +0200

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
IESG Secretary
Sent: Tuesday, April 13, 2010 9:00 PM
To: [email-masked]
Subject: WG Review: Congestion Exposure (conex) 

A new IETF working group has been proposed in the Transport Area.  The
IESG has not made any determination as yet. The following draft charter
was submitted, and is provided for informational purposes only. Please
send your comments to the IESG mailing list ([email-masked]) by Tuesday,
April 20, 2010.                                       

Congestion Exposure (conex)
--------------------------------------------------
Current Status: Proposed Working Group
Last Updated: 2010-04-08

Chair(s):
  TBD

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

Transport Area Advisor:
  Lars Eggert <[email-masked]> 

Mailing Lists:
  TBD

Description of Working Group:

The purpose of the CONEX working group is to develop a mechanism by
which senders inform the network about the congestion encountered by
previous packets on the same flow. Today, the network may signal
congestion by ECN markings or by dropping packets, and the receiver
passes this information back to the sender in transport-layer
acknowledgements, The mechanism to be developed by the CONEX WG will
enable the sender to also relay the congestion information back into the
IP layer, such that the total level of congestion is visible to all IP
devices along the path.

The primary goal of the CONEX WG is to develop experimental
specifications to achieve the above in IPv6 networks. The WG will also
develop an abstract, higher-level description of the congestion exposure
mechanism.

Primary work items are:

* An Informational document containing an abstract description of the
congestion exposure mechanism that is independent of specific transport
protocols and congestion information encoding techniques needed for
different IP protocol versions.

* An Experimental specification of an IPv6 packet structure that
encapsulates CONEX information, defining a packet format and an
interpretation.

* An Experimental specification of a modification to TCP, for the timely
transport of congestion information from the destination to the sender.

It is believed that the CONEX mechanism will be useful as a generative
technology that can be applied as a key element of congestion management
solutions in a wide variety of use cases. However, the CONEX WG will
initially focus on one use case, where the end hosts and the network
that contains the destination end host are CONEX-enabled but other
networks need not be. CONEX information can assist the network
operator's traffic management and, for example, incentivize LEDBAT-like
applications. Experiments on such use cases are encouraged and the WG
will solicit feedback from such deployments.
The WG may decide to document the experience from such use cases in
Informational documents, covering:

* Assumptions made

* Deployment considerations

* Advice on how to use the CONEX mechanism as an element of a congestion
management solution

* Security threats and advice on mitigation approaches (detailed
specifications of threat mitigation techniques are out of scope)

* Descriptions of results from experiments with the use case

The CONEX WG is only chartered to work a congestion exposure mechanism
for IPv6 networks. When the output of the WG has seen adoption and has
proven to be useful, the WG may propose to the IESG that it should be
rechartered to extend this effort.

Milestones

Mar 2011 Submit abstract specification for the congestion exposure
mechanism to IESG as Informational

Mar 2011 Submit use case description to IESG as Informational

Sep 2011 Submit specification of IPv6 packet structure to IESG as
Experimental

Sep 2011 Submit specification for modification to TCP to IESG as
Experimental