TCP Alternative Backoff with ECN (ABE)
RFC 8511

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: The IESG <>,,,,, =?utf-8?q?Michael_T=C3=BCxen?= <>,,
Subject: Document Action: 'TCP Alternative Backoff with ECN (ABE)' to Experimental RFC (draft-ietf-tcpm-alternativebackoff-ecn-12.txt)

The IESG has approved the following document:
- 'TCP Alternative Backoff with ECN (ABE)'
  (draft-ietf-tcpm-alternativebackoff-ecn-12.txt) as Experimental RFC

This document is the product of the TCP Maintenance and Minor Extensions
Working Group.

The IESG contact persons are Mirja Kühlewind and Spencer Dawkins.

A URL of this Internet Draft is:

Technical Summary

   The recently published RFC 8311 (Relaxing Restrictions on Explicit Congestion Notification (ECN) Experimentation) allows a TCP sender to react to an ECN signal in a different way than to a inferred loss signal if the behaviour is documented in an experimental RFC. This document describes such an experiment in which the reduction of the congestion window in response to an ECN signal is smaller than in response to an inferred packet loss. Therefore the TCPM working group requests publication as an experimental document.

Working Group Summary

   Was there anything in the WG process that is worth noting?
   For example, was there controversy about particular points 
   or were there decisions where the consensus was
   particularly rough? 

Document Quality

   The document has been discussed several times in working group meetings without any major controversy. There were also no substantial problems reported during the working group last call and it is implemented for FreeBSD (the code has been committed to the FreeBSD code base). The risk of running this experiment is relatively low, since the reaction to a loss is not changed. There is very strong consensus in the TCPM working group that this document should be published.


   The document shepherd is Michael Tüxen <>. The responsible Area Director is Mirja Kühlewind <>.