C35 controller and zoom issues

[wyomingohio]

We have a c35 controller with ap3935i and ap3965i access points.  We can run zoom no issue when hardwired and already check for any firewall issues that could be affecting.  But when on wireless it will randomly crash and lockup. Could happen 10 minutes into a meeting or 30 minutes in and when that happens we notice wireless issues on the device.  When not using zoom no issue we have no wireless issues.  This is happening across multiple devices and they are all various model devices as well.  So looking for some ideas if anyone has any on what next to check or setting recommendations to try.

[StephanH]

Hello,

It's hard to give concrete advice without knowing the details. Which client was used for testing, which WLAN standard does it use how many streams? Which settings are used in the controller for privacy, QoS and for the radio.

Have you done a Wireshark trace in the air and checked if there are many retransmissions?

Is it sure that during the test there is only one client connect to the AP?

Happens roaming during the test (can also happen if the client is on the same place!)

Basically you will finde best practise setting in the online help is you search for that:
“Achieving High Throughput with 11n and 11ac Wireless APs”

But data in Zoom is not special data. What matters here is that it is a constant data stream. But this is similar for any other video conference. 

[wyomingohio]

We have done a lot of that already.  We have tested with just one device attached to the AP and it is running AC and still same issue. Take the same machine hardwire no issues.  We have also verified bandwidth when this is happening as well and we are not even getting close to are available bandwidth.

We can have two people on zoom one hardwired and one wireless and the wireless will always drop out at some point in the meeting.   So have done a lot of that debugging already and everything comes back to the the wireless.  So was looking to see if extreme had some recommendations like many others do for optimizing for things like zoom.   But haven’t found one from extreme but again we have done a lot of various testing and debugging and everything right now is pointing back to the controller or AP’s being the issue. 

[StephanH]

Hello,

this is usually not a problem directly related to the hardware used.

It is probably due to the constant amount of data transferred during a zoom session (=video stream). Thus, the available bandwidth is used more than with other transfers (like email or web browsing).

Basically, you have to check how many clients are active at one of the affected APs and how much data they are transferring. This is followed by further steps. For example, you have to check whether all clients at the corresponding APs have AC turned on and whether the clients also support it. Or if there are slow clients (supporting only 802.11b/g)  that slow down the fast clients. There are many parameters on the controller and the clients. But you can't simply work through them here without seeing the system.

How to troubleshoot the WLAN is described in many articles online. You can also find a lot of information here:

https://www.extremenetworks.com/resources/ebook/wlan-troubleshooting/