Subject: Protocol Action: The Congestion Manager to Proposed Standard

From: The IESG <[email-masked]>
Date: Fri, 18 May 2001 13:32:57 -0400

The IESG has approved the Internet-Draft 'The Congestion Manager'
<draft-ietf-ecm-cm-04.txt> as a Proposed Standard.  This document is
the product of the Endpoint Congestion Management Working Group.  The
IESG contact persons are Allison Mankin Scott Bradner.

Technical Summary
 
   This specification describes the Congestion Manager (CM), an end-
   system module that:

   (i) Enables an ensemble of multiple concurrent streams from a
   sender destined to the same receiver and sharing the same
   congestion properties to perform proper congestion avoidance and
   control, and

   (ii) Allows applications to incorporate congestion avoidance
   and control algorithms easily, because it provides an abstract
   CM API that can be used from the application and that can be
   used by UDP-based applications.

   The CM maintains congestion parameters (available aggregate and per
   stream bandwidth, per-receiver round-trip times, etc.) and exports an
   API that enables applications to learn about network characteristics,
   pass information to the CM, share congestion information with each
   other, and schedule their data transmissions.  The current CM serves
   applications and transport protocols so long as the receiver stack
   and/or application provide feedback about received packets and losses.
   The CM does not require modifications to the receiver protocol stack,
   so it can be deployed in a piecemeal fashion.  The current CM serves
   best effort service environments.  Extensions can be developed in
   future to enhance use in networks with reservations and/or service
   differentiation.

Working Group Summary

  The working group reached strong consensus to advance the CM to the
  standards track.  The only dissent was focused on whether the
  the specification should be submitted without an accompanying document
  showing use of a non-round-robin scheduler among streams grouped
  by the CM into an ensemble or macro-flow.  The WG consensus on this
  question was that the scheduler example would be useful in future but
  was not necessary for advancing CM.

Protocol Quality

  The specification was reviewed for the IESG by Allison Mankin.
  A Linux open source implementation of the CM is available
  (http://nms.lcs.mit.edu/software/CM/).