A very good colleague of mine let me know about an issue that he had fixed. It was about direct routing in Teams.
The Teams environment couldn’t receive inbound calls using Teams DR via an SBC. Outbound calls were AOK.
They had configured an Azure DR at the same time BUT they had set the SBC FDQN the same as their own on-premises DRs.
Apparently, this cannot be.
The SBC FQDN in Teams cannot be the same name as the Azure Communication Services FDQN.
He pointed me to this page and highlighted this section:
That was cool, eh? So, the Teams SBC FQDN cannot match the Azure “virtual” SBC FQDN.
