I'm performing some testes regarding 802.11e (WMM/WME) performance, and I'm getting some unwanted results.

Im using an Lynksys 1200ac with OpenWrt/LEDE installed as AP, and two PCs lets say PC1 and PC2, both PCs are using the same wireless card model.

The AP is operating 2.4Ghz band only in 802.11n mode.

In the next example I'm sending two similar streams (using iperf3 -u -b 0), the red one is a downlink stream (from AP to PC1) and the green one is an uplink stream (from PC2 to AP).

Red - Downlink stream (AP- PC1)| Green - Uplink stream (PC2->AP)

i.stack.imgur(dot)com/0l7CY.png

From 15s to 45s Both streams are equal, from 50s to end the green(uplink stream) is marked as AC_VO.

I'm trying to find the reason why the downstream stream has so much more throughput than the uplink stream. Maybe the slottime is lower in AP thank in the clients? How can I check this?

Another question I have is regarding the capture that i made during this test,

As the AP is in 802.11n mode (where WMM support is mandatory) and WMM is enabled, it is supposedly using EDCA for channel access, but in the capture i have only a few RTS / CTS, and a lot of CF-End packets (shouldn't they only be sent when using PCF?)

Capture chunk showing an CF-end

i.stack.imgur(dot)com/VeBsX.png