Re: [tsvwg] Fwd: New Version Notification for draft-heist-tsvwg-ecn-deployment-observations-02.txt

[Pete Heist <[e-mail]>]

I'm following up in this thread to one question that's come up- why is
an ISP deploying fq_codel in its backhaul?

In short, this ISP encourages research and experiments by its members,
and this was a way to both see how much congestion exists, and attempt
to manage it with AQM when needed. Experiments with fq_codel were
started a couple of years ago, and I helped add support for it to their
custom router interface early last year. However, it's only actually
been enabled on a couple of routers, because:
- it takes a while to update routers in this environment
- some of the routers run kernels prior to fq_codel support
- congestion doesn't usually last long enough to give it much urgency,
and sometimes it's fixed by just adding capacity

IMO, fq_codel isn't ideal in this situation. When there actually is
congestion to manage, flow-fairness means that one user can dominate
the queue with many flows, which is exactly one of the problems we'd
like to avoid. Host fairness could improve on this, or better yet,
member fairness using the member database, as members can have more
than one IP/MAC. But, fq_codel is what's available now, and generally
usable enough in this case to get started with AQM.

On Mon, 2021-03-08 at 11:09 +0100, Pete Heist wrote:
> -------- Forwarded Message --------
> Subject: New Version Notification for draft-heist-tsvwg-ecn-
> deployment-
> observations-02.txt
> Date: Mon, 08 Mar 2021 01:57:07 -0800
> 
> > A new version of I-D, draft-heist-tsvwg-ecn-deployment-
> > observations-
> > 02.txt
> > has been successfully submitted by Peter G. Heist and posted to the
> > IETF repository.
> > 
> > Name:           draft-heist-tsvwg-ecn-deployment-observations
> > Revision:       02
> > Title:          Explicit Congestion Notification (ECN) Deployment
> > Observations
> > Document date:  2021-03-08
> > Group:          Individual Submission
> > Pages:          30
> > URL:           
> > https://www.ietf.org/archive/id/draft-heist-tsvwg-ecn-deployment-observations-02.txt
> > Status:        
> > https://datatracker.ietf.org/doc/draft-heist-tsvwg-ecn-deployment-observations/
> > Html:          
> > https://www.ietf.org/archive/id/draft-heist-tsvwg-ecn-deployment-observations-02.html
> > Htmlized:      
> > https://tools.ietf.org/html/draft-heist-tsvwg-ecn-deployment-observations-02
> > Diff:          
> > https://www.ietf.org/rfcdiff?url2=draft-heist-tsvwg-ecn-deployment-observations-02
> > 
> > Abstract:
> >    This note presents data gathered at an Internet Service
> > Provider's
> >    gateway on the observed deployment and usage of ECN.  Relevant
> > IP
> >    counter and flow tracking data was collected and analyzed for
> > TCP  
> > and other protocols.
> 
> A few updates in this version:
> 
> * Improved statistics for the separated "known" and "unknown" AQMs.
> 
> * Clarified the detection method for possible AQMs.
> 
> * Added possibility of QUIC-ECN traffic in non-TCP data.
> 
> Pete
> 
>