When packets get a priority between 1 and 7, which maps to a WMM traffic class (eg with [1]), I can’t get transmit more than 20-25Mbits/s UDP [2,3] shared to all clients. If I set the priority to 0 (or disable the rule), I get 440Mbits/s. I see the same to a range of 11ac clients, 5m from AP. The WMM enabled/disabled setting on the wlan interface doesn’t make a difference - perhaps only to change if WMM is advertised in the beacons.
Is 20-25Mbits/s expected/sufficient for video streaming to all clients on an AP? I feel it’s a bit low.
Priority 3 should the same as 0, ie best effort, but still gives 21Mbits/s max
This behaviour starves unmarked (DSCP 0) packets, which isn’t expected, agree?
Could the AP be using a low encoding rate to reduce the probability of drop?
Does anyone have any other experience with other equipment and WMM?
I raised this as ticket 2018102522005696 a week back, but no response yet. It would be good to get opinions.
Can you determine really what WMM is doing with the wireless frames? An over-the-air capture will show what actual value is put into the Qos Control header, in both directions.
Also, you are forcing the value at the AP. Can you try to use iPerf to force the DSCP value and see if that has any effect? That assumes the AP will convert the DSCP value to the appropriate 802.11e/WMM value.
Looks like I need a tagged vlan with proper QoS set here to actually have it respected by the radio driver and set the WMM QoS value. I was setting the DSCP value on wired → wireless packets at the IP header in iperf (on Linux, Windows did not work) but they had no impact - WMM value was always zero. Which is to be expected, per the manual.
Exactly. After setting WMM priority max throughput is 25Mbps on 802.11 WMM enabled link. After disabling 50+. Where is the problem? Tested on AP RB922UAGS-5HPacD with ROS v6.43.8 with client SXT Lite5 with ROS v6.43.8
Absolutely; support was first-class and did get on it! You need to set all radio queues to use aggregation with ‘/interface wireless set ampdu-priorities=0,1,2,3,4,5,6,7’; without block aggregation, the medium is quickly overwhelmed with management packets at the basic rate (typically 6Mb/s). By default only the default queue (0) is aggregated.
Mikrotik employees: what is the default setting in CAPSMAN? Just 0? Is there any aggregation at all? Can you add it in?
As this aggregation appears to be a hardware function it might be difficult to get it working in CAPSMAN when non-local forwarding is used as the host CPU does all the legwork apparently. Not that I want to make excuses for it not being implemented…
I always set priority from high 3 bits in post-routing for wireless interfaces but have never changed AMPDU from the default in the single setting of 0. If I could try AMPDU it might improve the throughput in some of the CAPSMAN systems, like when screen casting from Chromebooks and iPads and Macbooks or when I do a bulk app and IOS update.
by some reason mikroitk thinks we dont need all the wireless settings available in capsman
very frustrating knowing the hardware is capable of some features but you cant use it or adjust it in capsman
i think the strongest point of mikrotik in wifi is the vast amount of settings available in wireless, but some are not available in capsman which leaves mikrotik without their strong features, maybe in 6 or 12 months if more users complain about WMM and AMPDU settings mikrotik maybe put it on capsman
why i am saying that?
because i have tried to use capsman in wifi projects since its existence very frustrating, i like mikrotik but i end using other vendors because the inconsistency of capsman delivering features