Call2Teams - Customers
You have a user who, despite being able to make/receive Teams to Teams calls and receive PSTN calls, cannot make any outbound PSTN calls.
There are several potential causes of this issue, and these steps will help you to diagnose the issue so that you can take corrective action. Start by checking call status indicator on the Users page. If it is Red, the issue is most likely between Call2Teams and your PBX or Trunk. If it is not, then the issue is more likely between Call2Teams and Microsoft.
1a) Timeout error.
1b) Connection refused
Our attempt to send a call to the PBX/Trunk was refused. Check your PBX transport matches the expected settings on your firewall.
1d) See Also
2) You See an Unmatched Calls Warning
If there have been calls from Teams that did not match any of the users configured in the portal then this will be highlighted in red at the top of the Users page. This means the phone number sent by Teams didn't match any of the users you have configured in the portal.
Check that you have enough licences, and that the phone number configured in Teams matches the phone number configured in Office365.
If you have enabled Teams Sync , then click the Sync button to run another sync to make sure the numbers match.
3) Sync Errors
You can find further configuration information either in the contextual help links throughout the portal or via this support portal.
If you have exhausted all of the above options without success, then please raise a support case and provide logs and/or screenshots.