Broken WMM U-APSD and QoS with WAP devices

[muaddib_01]

Hello,

besides experiencing major performance and signal issues I have noticed that WMM UAPSD and QoS isn't working properly.

Even when the Client is requesting a buffer reales with QoS Null Data, the AP regurlaly doesn't send the content of the Queue, it waits till the scheduled buffered release. That behaviour is easily seen when pinging the Client with the same intervall as the beacon intervall and setting the DTIM higher.

Another problem ist, that QoS doesn't work at all. Putting the AP under higher load yields in high jitter and packet loss during a Voice call, although the client uses TSpec and the AP recognises the Voice Queue.

[Rasika Nayanajith]

Interesting to know about your test scenario & results of your observation in detail.

"Another problem ist, that QoS doesn't work at all. Putting the AP under  higher load yields in high jitter and packet loss during a Voice call,  although the client uses TSpec and the AP recognises the Voice Queue."

How did you configure your WLC QoS & Wired QoS ? What AP model you using & what is the WLC software code used for this testing ?

Rasika

[muaddib_01]

Hello,

the Thread belongs to SMB Wireless Devices, WAP300 and WAP500 series.

The QoS is configured correctly, VoIP data goes to WMM AC_VO. The Configuration doesn't allow to change DSCP to WMM Queue mapping, but the clients are confgured to mark VoIP-Data with EF.

[Rasika Nayanajith]

Hi Paul,

I read below admin guide to see what level of QoS these product supports (as I haven't use these products). It looks like it will allow basic QoS config which you already configured. So nothing much we can do on AP itself.

http://www.cisco.com/en/US/docs/wireless/access_point/csbap/wap121/administration/guide/WAP121_321_AG_en.pdf

Where is the other end of your voice calls ? Is there any wired network involve ? Have you configured any QoS in switches where these AP connected ? That may be something you should look at if it is go beyond this AP & into wired network.

HTH

Rasika