Subject: WGLC Announcement for draft-ietf-tsvwg-byte-pkt-congest-07 - 14th March 2012

From: Gorry Fairhurst <[email-masked]>
Date: Wed, 14 Mar 2012 08:38:26 +0000

This email announces the start of a working group last call for
draft-ietf-tsvwg-byte-pkt-congest-07, "Byte and Packet Congestion 
Notification". This document is now thought to be ready
to proceed to be published as a BCP. Please send any comments to the
TSVWG list.

The draft is available at:
http://tools.ietf.org/html/draft-ietf-tsvwg-byte-pkt-congest-07

The last call will run for TWO weeks, ending Friday 30th March 2012.

Emails saying "I support" or "I don't support" publication are also most 
helpful in judging the WG consensus. Please let us know if this draft is 
useful and seems to provide the correct advice.

James and Gorry
(TSVWG Chairs)
[email-masked]

---

From: Gorry Fairhurst <[email-masked]>
Date: Wed, 28 Mar 2012 15:01:32 +0200

Please respond to the WGLC that ends on Friday 30th March 2012.

Notes to the list would be helpful to complete the WGCC.

Gorry & James

-------- Original Message --------
Subject: WGLC Announcement for draft-ietf-tsvwg-byte-pkt-congest-07

James and Gorry
(TSVWG Chairs)
[email-masked]

---

From: John Leslie <[email-masked]>
Date: Fri, 30 Mar 2012 11:50:02 -0400

> Notes to the list would be helpful to complete the WGCC.

   I cannot support this draft as written.

   Perhaps some background would help...

   It will be no secret to anyone following the ConEx WG that Bob and I
fundamentally disagree about whether to model congestion as per-packet
or per-byte. I strongly believe that it's packets that are congested, and
that we'll do better to accurately count congested packets than estimate
congested bytes; Bob seems to strongly believe that we'll do better to
estimate congested bytes than accurately count congested packets.

   When I previously skimmed this document, I believed it contained only
common ground: that AQM should drop/mark packets without favoring small
packets, and that to whatever extent packet size _is_ considered, that
should be a transport-layer responsibility.

   Alas, when I read it carefully this week, I find that Bob is actually
saying that transport-layer should _only_ consider "congested bytes", not
"congested packets".

   In fact, Bob openly endorses replacing TCP congestion-control with an
algorithm which calculates "fair-share bytes" and doesn't back off at all
(even in the presence of 20% packet loss) unless you're already sending
more than this "fair-share".

   I do not believe that is the consensus of this WG; and I believe if
that were the consensus it would exceed our charter.

   The draft contains a number of things I _do_ support; and I'd be happy
to support a considerably shorter draft which concentrates on the AQM
recommendation, omitting any suggestions of modifying TCP congestion
control.

--
John Leslie <[email-masked]>