RE: Upstream bandwidth usage

[Adam Thompson <athompson () merlin mb ca>]

On DOCSIS systems, upload/download ratios are frequency-mapped timeslot ratios that are not adjustable in real-time.
On xDSL systems, upload/download ratios are - VERY roughly speaking - a function of how much spectrum is allocated to 
each direction based on each individual line's characteristics, and also not adjustable in real-time.
Most fixed-wireless systems have similar limitations to one or the other above, although they vary in the details.

Anecdote: I used to maintain/sell/support a system that could automatically "tune" DSL service for the prevailing line 
conditions (as these change with age, weather, interference, etc.) and I recall learning from one customer that 
auto-tuning any more often than every 24hrs became *severely* counter-productive, because the connection had to drop 
and re-negotiate every time a change was made because of the way DSL modems work; our product had to incorporate a 
fall-back where we reverted to ADSL 1M rates if the line was still down an hour later, in case the remote modem just 
refused to renegotiate at what should have been a perfectly valid profile (speed) for some reason or other.


So the short answer is: because the harder limitation to solve is the last-mile technology, not the choke-points at the 
network edges where shaping happens.  All that rate-shaping in the core is generally about preventing the downstream 
packet(s) that would overload the last-mile from ever reaching the last-mile device in the first place.


However, if you're talking about fiber service, it's pretty much pure marketing-dept-driven BS, combined with some 
vague justification of not letting TOR nodes or copyright-ignoring seeders/Warez-providers/etc. overwhelm the network 
in unexpected ways.


-Adam (who acknowledges he runs a very unusual SP network where rate-limiting is unheard of)

Adam Thompson
Consultant, Infrastructure Services
MERLIN
100 - 135 Innovation Drive
Winnipeg, MB R3T 6A8
(204) 977-6824 or 1-800-430-6404 (MB only)
https://www.merlin.mb.ca
Chat with me on Teams: athompson () merlin mb ca

> -----Original Message-----
> From: NANOG <nanog-bounces+athompson=merlin.mb.ca () nanog org> On Behalf
> Of Michael Thomas
> Sent: Thursday, June 9, 2022 3:46 PM
> To: nanog () nanog org
> Subject: Re: Upstream bandwidth usage
>
>
> On 6/9/22 1:26 PM, Mel Beckman wrote:
> > With 430 GB versus 32 GV average down versus up usage today,
> according
> > to your article, this is still not a case for symmetrical consumer
> > bandwidth. Yes, the upstream usage increased slightly more than the
> > downstream usage. But the ratio was still so big that it would take
> > decades for them to join. I doubt they ever will. Consumers just
> don’t
> > have that much days up to push yet, and probably never will.
> >
> > Also, a lot of that Usage can be explained by video conferencing
> > during Covid, which has dropped off significantly already.
> If it's so tiny, why shape it aggressively? Why shouldn't I be able to
> burst to whatever is available at the moment? I would think most users
> would be happy with that.
>
> Mike