[Cerowrt-devel] [Make-wifi-fast] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e

[Rich Brown]

Ah..., the bitter bit of the reality sandwich. Yum :-(

But Dave's note about Felix's hook for per-station queueing makes it seem feasible, if only a lot of work.

Thanks, all, for the enlightenment!

Rich

On Aug 7, 2015, at 9:28 AM, Jonathan Morton <chromatix99 at gmail.com> wrote:

> 
>> On 7 Aug, 2015, at 15:22, Rich Brown <richb.hanover at gmail.com> wrote:
>> 
>> - At that time, the wifi driver requests packets from fq_codel until a) the the fq_codel queues are empty, or b) the wifi frame is full. In either case, the wifi driver sends what it has.
> 
> There’s one big flaw with this: if packets are available for multiple destinations, fq_codel will generally give you a variety pack of packets for each of them.  But a wifi TXOP is for a single destination, so only some of the packets would be eligible for the same aggregate frame.
> 
> So what’s needed is a way for the wifi driver to tell the queue that it wants packets for the *same* destination as it’s transmitting to.
> 
>> - Once the transmit opportunity has come around, it's a matter of microseconds (I assume) to pull in a wifi frame's worth of packets from fq_codel
> 
> This is hard to guarantee in software in a general-purpose OS.
> 
> - Jonathan Morton
>