PSTN callers can't hear us

[Bob Manjoney]

1. Teams Only organization w/Phone System/Calling Plans

2. Polycom VVX VoIP phones (latest SfB online certified firmware)

When someone calls in, the Polycom phones and Teams apps that are logged into that account ring, but when we answer one of the Polycom phones, the person calling us cannot hear us. We can hear them. This happens about 3/4 of the time, but not always, and with seemingly no pattern. It doesn't seem to happen when answering using the actual Teams app - only when using the Polycom phones.

I've checked out our firewall settings and we are not blocking any of the documented ports or ranges of ports that need to be open, and there is nothing in the actual call log that indicates something is going wrong. I'm at a loss as to how to even begin troubleshooting this. Any advice as to where I can look for clues?

Thanks,

Bob

[#2]

@Bob Manjoney running into similar issue, did you come to any resolution?

[#3]

It's been an ongoing nightmare, tbh. For those clients of mine who chose to *not* dump MS Phone System as a result of this, they instead have abandoned the Polycom VVX 3PIP phones and bought Poly CCX native Teams desk phones. Things are slightly better, but they all still have call drop issues routinely, issues with 2 way audio, and issues placing calls on hold that can not be retrieved. I'm right at this moment have a case open that's going around in circles and getting nowhere as usual.