Teams Video not transmitting

[ivantalboys]

Hello

 

We have an issue with all our users when using the Teams client to attend meetings. No video is transmitted to the meeting and you can't see other attendees videos. The preview in the client of your own webcam is displayed for 25 seconds and then blacks out. If you turn off the camera and back on again you get another 25 seconds of preview before it blacks out, all the while no video is being transmitted. Other aspects of the meeting work fine, audio, screen sharing, chat etc. It is just video. This is only in the client, the web version of teams is fine.

 

Things we have checked:

 

• Ports 3478, 3479, 3480, 3481 are all open and packet sniffing suggests the traffic is flowing across these ports.
  
• We are using a non-domain joined laptop to test so no GPOs or other settings are interfering.
  
• We get our internet from the LA who use Smoothwall filtering, we have disconnected our entire network from their router, plugged in the test laptop directly and still have the problems.
  
• When using this laptop on a separate internet connections (mobile hotspot) it works fine.
  
• The results of https://connectivity.office.com/ comeback as everything is OK
  

 

We raised a support call with MS and their initial response was to check their published Endpoints were accessible as well as checking QoS. They have taken some logs though and are looking into it but we have yet to hear back.

We have a support call with our LA who can't find any issue with the traffic and say that the endpoints are open and optimised.

 

The behaviour suggests the Teams client tries to make a connection for the video, tries unsuccessfully for 25 seconds and then gives up, blanking the preview to alert the user to this fact. As this only happens on the LA connection something network related appears to be the cause but no-one is able to determine what.

 

Has anyone else had this issue or any other suggestions on what to try next?

 

Thanks

Ivan

[chazzy2501]

I have a similar issue only with my older HP laptops the Elitebook 8460p and 8470p. The webcams will be black always, sometimes work (if turn off video and on again) and sometimes go black whilst working.

 

I will also state that the issue only occurs with the teams desktop client. zoom, the camera app are all fine.

 

All my devices use the same network and firewall, so you may want to investigate drivers or device firmware. (hp bios updates do camera firmware sometimes?!)