Hi all,
I finally have my testbed
working the way I want and am starting to run tests to see if
OFDMA does anything useful.
This will all be covered in detail in an upcoming
SmallNetBuilder article. But I wanted to sanity check something
with this esteemed group.
The tests are basically the flent rtt_fair_var up and down tests
ported to the octoScope platform I use for WiFi testing.
The initial work was done on flent, with a lot of hand-holding
from Toke. (Thank you, Toke!)
Using 4 Intel AX200 STAs on Win10. iperf3 is running traffic
using TCP/IP with unthrottled bandwidth. I've taken Bjørn's idea
and have each STA using a different DSCP priority level, but
with TCP/IP traffic, not UDP. I'm sticking to using CS0-7
equivalents and confirmed that the iperf3 --dscp values properly
translate to the intended WiFi priority levels. Each STA has a
different priority, either CS0,3,5 or 6 (best effort, excellent
effort, video and voice).
Ping is used to measure latency and always runs from AP to STA.
Only TCP/IP traffic direction is reversed between the down and
uplink tests.
One thing that jumps out immediately is that uplink latencies
are *much* lower than downlink, with either OFDMA on or off.
Attached are three examples. The CDFs are average latency of the
4 STAs.
The NETGEAR R7800 is a 4x4 AC Qualcomm-based. I'm using this as
a baseline product.
The NETGEAR RAX15 is 2x2 AX Broadcom-based. You can see what I
mean when I say OFDMA doesn't help.
Does this much difference between up and downlink latency pass
the sniff test?