[Codel] [Make-wifi-fast] [RFC/RFT] mac80211: implement fq_codel for software queuing

David Lang david at lang.hm
Mon Mar 21 21:29:53 EDT 2016

On Mon, 29 Feb 2016, Michal Kazior wrote:

>> Our intent is to continue to improve the flent test suite to be able
>> to generate repeatable tests, track relevant wifi behaviors and pull
>> relevant data back, graphed over time (of test) and time (over test
>> runs). A problem with udp flood tests is that tcp traffic is always
>> bidirectional (data vs acks), so a naive thought would be, that yes,
>> you should get half the bandwidth you get with a udp flood test.
> I don't see why you'd be doomed to get only half the bandwidth because
> of that? Sure, Wi-Fi is half-duplex but transmit time for ACKs is a
> lot smaller than transmit time for the data.

The difference is actually far less than you think. Each transmission has a 
fixed-length header and quiet times that were designed in the days of 802.11b 
(1-11Mb) and if you are transmitting a wide 802.11ac signal at a couple hundred 
Mb, you can find that the time taken to transmit even full packets is a 
surprisingly small percentage of the total transmit time.

David Lang

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