> The current best practice seems to be to instantiate cake/SQM on a reasonably 
> fixed rate wan link and select WiFi cards/socs that offer decent airtime 
> fairness.
> Works pretty well in practice...

Yes, AQL does essentially the right thing here, again along the lines of 
limiting the influence of one machine's load on another's performance, and 
completely automatically since it has faurly direct information and control 
over the relevant hardware.  Cake is designed to deal with wired links where 
the capacity doesn't change much, but the true bottleneck is typically not at 
the device exerting control.

On that note, there is a common wrinkle whereby the bottleneck may shift 
between the private last mile link and some shared backhaul in the ISP at 
different times of day and/or days of week.  Locally I've seen it vary between 
20M (small hours, weekday) and 1Mbps (weekend evening).  When Cake is 
configured for one case but the situation is different, the results are 
obviously suboptimal.  I'm actually now trying a different ISP to see if they 
do better in the evenings.

Evenroute's product includes automatic detection of and scheduling for this 
case, assuming that it follows a consistent pattern over a weekly period.  Once 
set up, it is essentially a cronjob adjusting Cake's parameters dynamically, so 
providing a manual setup for the general OpenWRT community should be feasible.  
On “tc qdisc change”, Cake usually doesn't drop any packets, so parameters can 
be changed frequently if you have a reason for it.
_______________________________________________
Bloat mailing list
[email protected]
https://lists.bufferbloat.net/listinfo/bloat

Reply via email to