What causes the "Your network is causing poor call quality" bubble to appear?

[tkramerJH]

I've been seeing the "Your network is causing poor call quality" bubble pop up sometimes, and I can't seem to find any documentation on what would trigger it to appear (See https://i.imgur.com/ItS9JUC.png - sorry for the poor quality). I evaluated a call yesterday where this appeared and the pings were all below 30ms, jitter maxed out at 8ms, and the Concealed Sample Ratio hit 1.72%. These are all below the MS guideline shown at https://blogs.technet.microsoft.com/jenstr/2013/09/20/what-is-the-basis-for-classifying-a-call-as-po... .

The only anomaly was that one one side of the call populated with QoE data, not the other. I'm imaging this is caused by the far side. Normally I'd dismiss as a small network anomaly (as this is a Fiber broadband circuit, not MPLS or DIA), but I have a user who's been a particular thorn in my side on call quality questions, and I can't answer this one in particular.

Anyone have any insight into what causes that bubble? Even looking through the Teams logs I can't find a darned thing.  I haven't seen it yet this week - so it's possible an update changed this behavior, but I would still love to know what causes this to appear.

[#2]

@tkramerJH 

we have 5 metrics that we use to classify a stream as poor, and when any of the 5 metrics go over the threshold, we'll provide the user the pop up.  

https://docs.microsoft.com/en-us/MicrosoftTeams/stream-classification-in-call-quality-dashboard

You can troubleshoot any of these in the Call Analytics dashboard in the Teams Admin portal.  Anyway, one of these conditions were exceeded and caused this message to appear.

[#3]

@Gregory Maynard - Thanks!  I had assumed that, but I was never able to locate anything crossing that threshold in the call logs at the time.  I'll look again next time I see it.

Also, on peer-to-peer calls, will both parties see this even if one party is not causing the poor experience?  I've noticed in call quality logs between two Teams users inside our organization that the call quality metrics are the same on both sides, which seems to make it difficult to determine where the issue is.  This causes some confusion with our users, such as when a near-end hardwired user on a dedicated, high quality network connection sees this pop-up, and I'm thinking it could be caused by the far end having a poor quality connection, not the near end.

Thanks again for the reply!  I've been trying to solve this mystery for quite a while.

Tony