> On Feb 16, 2017, at 5:21 PM, Sebastian Moeller <[email protected]> wrote:
> 
> 
>> On Feb 16, 2017, at 17:15, Aaron Wood <[email protected]> wrote:
>> 
>> The approach that's in all of the Cisco documentation (FWIW) about such 
>> things for wired networks is that the higher-priority traffic classes for 
>> VoIP and video are also bandwidth limited to a fraction of the total (and 
>> less than a majority, at that).  But that's in an environment where you 
>> _can_guarantee a minimum level of service.  With the changing throughput 
>> rates of wifi, that's a bit harder.
>> 
>> But I can certainly see the case being made that the VO and VI queues are 
>> never allowed to be over X% of traffic.
> 
>       I guess the problem is that any station can just decide by itself to 
> just send AC_VO and in a typical home steup the AP will not get a say in 
> that. This is why I propose the AP to escalate its own priority marking to 
> get its packets distributed… In a sense if there are thresholds for 
> permissible VO/VI traffic fractions below which the AP will not escalate its 
> own priority this will come close to throttling the high priority senders, 
> no? 

I thought Aaron’s suggestion sounds both sensible and not difficult to 
implement. That way we wouldn’t even have to regularly monitor it, and anyone 
who is marking all their packets thinking they’re doing themselves a favor is 
just limiting their max throughput.

Could there be another keyword in Cake to do this automatically, say 
“fairdiffserv", or would this just be feature bloat for what is already a 
sophisticated shaper? I don’t know if there are sensible mappings from dscp 
value to max percentage throughput that would work most of the time, or if 
there could also be an adjustable curve parameter that controls the percentage 
backoff as you go up dscp levels.

Sebastian, I wasn’t sure what you meant by the AP’s “own packets”, ones that 
originate from the AP? One thing with might happen if you raise some priorities 
is there may be an arms race, and also once packets are forwarded to an 
upstream router with an already elevated priority they might unfairly compete 
there, but maybe you meant only to treat some packets differently in the AP, 
not to actually change the value in the DSCP field...

Pete

_______________________________________________
Cake mailing list
[email protected]
https://lists.bufferbloat.net/listinfo/cake

Reply via email to