Subject: [Tsvwg] Initial I-D: draft-briscoe-tsvwg-byte-pkt-mark-00

From: Bob Briscoe <[email-masked]>
Date: Sun, 17 Jun 2007 04:28:45 +0100

James & everyone,

I've just posted this. It will appear in internet-drafts shortly, but for 
now, you can get it from the link to my page below:
         Byte and Packet Congestion Notification
<http://www.cs.ucl.ac.uk/staff/B.Briscoe/projects/2020comms/refb/draft-briscoe-tsvwg-byte-pkt-mark-00.txt> 
Header block & abstract below.

It is motivated at this time by the need to define whether to take packet 
size into account for the marking algo in the PCN w-g. But it's generalised 
to give strong advice (unlike my usual style ;) on RED for diff size pkts, 
and also relevant to TFRC-SP in DCCP, but it's aimed primarily at tsvwg as 
a general transport-area-wide subject.

It includes a survey of >100 vendors asking if they implemented the 
byte-mode packet drop variant of RED. With ~10% responses in, they've all 
said no.

Cheers

Bob
=============================================================================
Transport Area Working Group                                  B. Briscoe
Internet-Draft                                                  BT & UCL
Intended status: Informational                             June 17, 2007
Expires: December 19, 2007

                 Byte and Packet Congestion Notification
                   draft-briscoe-tsvwg-byte-pkt-mark-00

Abstract

    This memo was written to clarify how (and whether) to take packet
    size into account when notifying congestion using active queue
    management (AQM) such as random early detection (RED).  The scope
    includes resource congestion by bytes and by packet processing, even
    though the latter is less common.  It answers the question of whether
    packet size should be taken into account when network equipment
    writes congestion notification, or when transports read it.  The
    primary conclusion is that RED's byte-mode packet drop should not be
    used because it creates a perverse incentive for transports to use
    tiny segments.  TCP's lack of attention to packet size should be
    fixed in TCP, not by reverse engineering network forwarding to fix
    transport protocols.
=============================================================================

____________________________________________________________________________
Notice: This contribution is the personal view of the author and does not 
necessarily reflect the technical nor commercial direction of BT plc.
____________________________________________________________________________
Bob Briscoe,                           Networks Research Centre, BT Research
B54/77 Adastral Park,Martlesham Heath,Ipswich,IP5 3RE,UK.    +44 1473 645196