Re: [tsvwg] sce vs l4s comparison plots?

Dave Taht <dave@taht.net> Mon, 11 November 2019 18:25 UTC

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From: Dave Taht <dave@taht.net>
To: "alex.burr\@ealdwulf.org.uk" <alex.burr@ealdwulf.org.uk>
Cc: Tom Henderson <tomh@tomh.org>, tcpm@ietf.org, tsvwg IETF list <tsvwg@ietf.org>
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Date: Mon, 11 Nov 2019 10:25:08 -0800
In-Reply-To: <1369738724.1583995.1573472465758@mail.yahoo.com> (alex's message of "Mon, 11 Nov 2019 11:41:05 +0000 (UTC)")
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Subject: Re: [tsvwg] sce vs l4s comparison plots?
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"alex.burr@ealdwulf.org.uk" <alex.burr@ealdwulf.org.uk> writes:

> (see below)
>
> On Monday, November 11, 2019, 12:19:26 AM GMT, Dave Taht
> <dave@taht.net> wrote: 
>
> Cool. If only the dsl and cable worlds had adopted this! it allows for
> much smarter handling of packet delivery higher in the stack at the
> cost
> of one interrupt's worth of standing queue. Without BQL we wouldn't be
> scaling linux past 10GigE today.
>
> I keep hoping *switches* will start doing bql, also.
>
> [AB] at the CO end (ie downstream) my understanding (which may be out
> of date) 
> is that DSL ICs usually punt queuing to a switch IC. There's a
> standard (G999.1) which exists
> solely to enable this (it provides per-subscriber backpressure over
> ethernet). So, switches doing
> BQL is exactly what would be required for dsl to do BQL (in the
> downstream direction).

Given that a lot of stuff has moved to a purer software solution,
slicing, sdn, etc, including switching, I can imagine this would
move more into software, also - if folk were still producing new
dsl gear.

One thing that has always been unclear to me is where
dsl subscriber software rate limits are enforced. 

>
> (Given BQL is a workaround, switches would want to implement a direct
> solution if they do anything).

I'd hope so!

>
> Alex