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The Benefits of Using Explicit Congestion Notification (ECN)
RFC 8087

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: "IETF-Announce" <>
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Subject: Document Action: 'The Benefits of using Explicit Congestion Notification (ECN)' to Informational RFC (draft-ietf-aqm-ecn-benefits-08.txt)

The IESG has approved the following document:
- 'The Benefits of using Explicit Congestion Notification (ECN)'
  (draft-ietf-aqm-ecn-benefits-08.txt) as Informational RFC

This document is the product of the Active Queue Management and Packet
Scheduling Working Group.

The IESG contact persons are Spencer Dawkins and Martin Stiemerling.

A URL of this Internet Draft is:

Ballot Text

Technical Summary

This document is mostly a list of demonstrated and expected benefits to 
transport protocols by using ECN. It highlights points that are most 
visible to the application layer within the end-points. It then goes on 
discussing specific deployment scenarios of ECN in a network, and the 
internet at scale. 

The key benefits of running ECN are summarized as
o) Improved throughput                                 
o) Reduced Head-of-Line blocking                       
o) Reduced probability of RTO Expiry                   
o) Applications that do not retransmit lost packets    
o) Making incipient congestion visible                 
o) Opportunities for new transport mechanisms  

Working Group Summary

The document was brought to the working group to highlight and underline the
many benefits ECN can have, if deployed at scale. During the WG discussions, the
character of the draft changed slightly, from looking only at the positive 
implications to also describe potential drawbacks and pitfalls.

The intention of this document though is less technical in nature, and instead is 
intended as a reference as to why deploying ECN at this time would be sensible. 
It aims to be a manifest that can be shown to decision-makers who quickly need
to understand the key benefits of ECN, with a high level of technical guidance.

Document Quality

Are there existing implementations of the protocol? 

The document is agnostic of any specific implementation, and rather argues
about the architectural model (well, as supported by the IP protocol) to use
ECN. Implementations of ECN in TCP (RFC3168) are in wide-spread use, but with
the ECN capabilities disabled, or only passively enabled. Arguably, the document
helped to persuade decision-maker at a large vendor to actively start deploying 

Have a significant number of vendors indicated their plan to implement the 

The document aims to achieve just that - to drive the adoption rate of a well
known and available protocol by vendors up.

Are there any reviewers that merit special mention as having done a thorough 
review, e.g., one that resulted in important changes or a conclusion that the 
document had no substantive issues? 

There were lively discussions in the AQM working group around this document.
First, to not only speak exclusively about the positive aspects, but also 
mention potential issues. Second, that document had widespread support in the WG
as it preaches to the choir - but word has to be spread about ECN to a larger

Who is the Document Shepherd? 
Richard Scheffenegger, AQM WG co-chair

Who is the Responsible Area Director?
Martin Stiemerling, Transport AD

RFC Editor Note