Congestion Exposure (ConEx) Concepts, Abstract Mechanism, and Requirements
RFC 7713

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    conex mailing list <>,
    conex chair <>
Subject: Document Action: 'Congestion Exposure (ConEx) Concepts, Abstract Mechanism and Requirements' to Informational RFC (draft-ietf-conex-abstract-mech-13.txt)

The IESG has approved the following document:
- 'Congestion Exposure (ConEx) Concepts, Abstract Mechanism and
  (draft-ietf-conex-abstract-mech-13.txt) as Informational RFC

This document is the product of the Congestion Exposure Working Group.

The IESG contact persons are Spencer Dawkins and Martin Stiemerling.

A URL of this Internet Draft is:

Technical Summary

   This document describes an abstract mechanism by which senders inform
   the network about the congestion encountered by packets earlier in
   the same flow.  Today, network elements at any layer may signal
   congestion to the receiver by dropping packets or by ECN markings,
   and the receiver passes this information back to the sender in
   transport-layer feedback.  The mechanism described here enables the
   sender to also relay this congestion information back into the
   network in-band at the IP layer, such that the total amount of
   congestion from all elements on the path is revealed to all IP
   elements along the path, where it could, for example, be used to
   provide input to traffic management.  This mechanism is called
   congestion exposure or ConEx.  The companion document "ConEx Concepts
   and Use Cases" provides the entry-point to the set of ConEx

Working Group Summary

There were no special issues worth noting during the WG process.

Document Quality

The document received several thorough reviews. It is worth noting the
reviews from Mirja Kuehlewind and David Wagner.


Marcelo Bagnulo ( is the document shepherd.
Martin Stiemerling ( is the responsible Area Director.