[Cerowrt-devel] ath9k WMM not obeying DSCP/TOS flags?

leetminiwheat LeetMiniWheat at gmail.com
Sat Apr 18 06:37:57 EDT 2015

On Sat, Apr 18, 2015 at 2:57 AM, Dave Taht <dave.taht at gmail.com> wrote:

Thanks for the replies, very informative!

>> WMM seems particularly useful for mobile devices and/or crowded
>> airspace, so I'd like to somehow get this working right.
> No it is not useful for crowded airspace, unless you are trying for a temporary
> game theory win over everyone else that is not using wmm.
> I have long documented the ills of the VO queue in general in benchmarks
> and documentation on how it interacts badly with aggregation. As for
> using the BK queue effectively, a common problem is that much traffic
> is mis-marked as CS1 that should not be. I donĀ“t recall disabling it in
> the stable release of cerowrt, nor did I attempt to push the patch up
> to openwrt, so openwrt probably continues to (mis)use the VO queue.
> In general, you do best by minimizing TXOPs and maximizing aggregation
> in crowded wifi environments.

Are you sure mobile phones don't treat VO differently, such as
disabling more power savings features in order to handle VO packets
better? I did notice an improvement in a voice-chat app through the VI
queue but It's still not perfect. with PINGOPT=1 the device jitters
between 2ms-300ms with little to no traffic, 2ms-150ms with txqueuelen
16, but with constant downstream traffic it holds steady around 3ms.
My thinking was perhaps VO packets would keep it from doing tricks
with aggregation and causing delay and static in voice chat apps that
don't set their traffic properly to the client OS.

> Gaining the resources to fix wifi has eaten most of the last 10 months
> of my life, AFTER helping come up with some of the theoretical fixes
> over the last 4 years. We are finally in a position to make a run at
> making deployable some of the same latency reducing techniques we have
> successfully applied to wired links to wifi, but MUCH work remains,
> and nearly zero funding exists, still. I had honestly hoped to be able
> to fully prototype and test the fixes over the summer, but that hope
> fades more and more every day.

Well I for one greatly appreciate all the work you and everyone else
has done to fix networking. I wouldn't hesitate to donate if I was in
a financial position to do so. Thanks again for the reply and for
clearing some things up that i was scratching my head over.

P.S. amazing stuff in your debloat script! though hard to read even
with a decent understanding of LUA. Can't seem to get it to change
txqueuelen though even after installing ethtool, fixing the path, and
appending FORCE_RING='tx 16' to hotplug/iface/00-debloat, but I've got
a custom init script at the end boot that does most of what I need. I
understand at this point (if time/finances were permitted) you'd be
working on chaos calmer which doesn't even use hotplug anymore

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