Microsoft Teams Direct Routing - Call forwarding isn't working

Hi DominikA9522 ,

The error message "We cannot connect you" with the reason "Q.850;cause=79;text="b5630f10-1117-4a37-9208-dc10a476f35a;FinalAnswerError"" indicates that there is an issue with the call forwarding configuration or the interaction between Microsoft Teams and your local PBX.

To troubleshoot this issue, here are some steps you can follow:

1. Verify call forwarding configuration: Double-check the call forwarding settings for User B in Microsoft Teams. Ensure that the forwarding number or User C's external device is correctly entered.

2. Check PBX configuration: Verify the configuration of your local PBX (OpenScape Voice). Ensure that the necessary routes and rules are in place to handle call forwarding properly. Review the call forwarding settings for User B in the PBX and confirm they are correctly configured.

3. Review SBC configuration: Examine the configuration of your OpenScape SBC. Ensure that it is properly configured to handle call forwarding scenarios between Microsoft Teams and your local PBX. Check for any error logs or configuration issues that might be causing the problem.

4. Analyze SIP signaling: Use packet capture or logging tools to capture and analyze the SIP signaling between Microsoft Teams, the SBC, and your local PBX. Look for any error messages or unexpected behavior during the call forwarding process. Pay attention to any specific error codes or messages that may provide further insights into the issue.

5. Engage vendor support: If you are unable to resolve the issue with the above steps, it would be advisable to reach out to the support teams of Unify (manufacturer of OpenScape Voice) or your SBC provider. They will have specific knowledge of their systems and can assist you in troubleshooting the call forwarding problem.

By following these steps and involving the appropriate support channels, you should be able to identify and resolve the issue with call forwarding to an external number or device in your Teams and PBX configuration.