Teams Outbound calls Issue

Question

Hi,

I am having an issue calling outbound calls from MS Teams. Its dialing but i am not seeing any messages on my SBC. Any possible reason or configuration needs to be done for outbound calls?

Answer 1

Dear @UG,

You might experience various issues when you use Direct Routing to make outbound calls from a Microsoft Teams client to a Session Border Controller (SBC). These issues include the following:

• An incorrect caller ID is displayed to the call recipient.
• A connection to the SBC is not established.
• Some users in a tenant are unable to make calls.
• No users in a tenant are able to make calls.

This article discusses potential causes of these issues and provides resolutions that you can try. For reference, please refer to: Issues that affect outbound direct routing calls

Please kindly check if you turn on Teams notification in your IOS/Android device. For more details, please kindly check the solution provided in this article Troubleshoot notifications in Microsoft Teams mobile apps - Microsoft Support and the call settings in Teams client and ensure you have ticked "Call rings me" option.

Enable Location Services on Mobile

• Go to Settings > Privacy > Location Services
• Ensure Microsoft Teams has permission to access location
• Restart the Teams app and try again

In the meantime, here are these troubleshooting steps you can try:

1. Microsoft Teams: update to the latest version.
2. Sign out and log back in: This will refresh your account linking and may resolve the issue. 
3. Clear Teams cache: Cached data can sometimes cause problems. Clear the Teams client cache
4. Reinstall Teams: If the problem persists, try completely uninstalling and reinstalling it. 

Uninstall first: Uninstall Microsoft Teams

Then reinstall: Download Microsoft Teams Desktop and Mobile Apps | Microsoft Team

Note: If none of the above solutions work, let me know for further investigation. Please note that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.   

Please feel free to reach out if you have any questions or need further clarification.

Your understanding and co-operation are highly appreciated. Thank you for your precious time. Have a nice day!

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Answer 2

If outbound calls are dialing in Teams but nothing appears on the SBC, the calls are likely not reaching the SBC at all. Focus on Direct Routing gateway status and network/SIP signaling path.

Use these checks:

1. Verify the Teams PSTN gateway is enabled
   • In the Teams admin center, confirm the SBC gateway used for Direct Routing is available and enabled.
   • Or use Teams PowerShell:

          Get-CsOnlinePSTNGateway | fl Identity,Fqdn,SipSignalingPort,MaxConcurrentSessions,Enabled
     

   • Ensure the Enabled parameter for the relevant SBC (for example, sbc1.contoso.com) is True.
   • If it is False, enable it:

          Set-CsOnlinePSTNGateway -Identity "<your-sbc-fqdn>" -Enabled $true
     

   • Re‑run Get-CsOnlinePSTNGateway to confirm the change.
2. Confirm SIP OPTIONS reach the SBC (network/firewall)
   • If no users can make calls and the SBC shows no SIP traffic, a device on the path (firewall, router, IDS/IPS) may be blocking SIP signaling.
   • Ensure all required SIP signaling IPs and FQDNs for Direct Routing are allowed on every network device between Teams and the SBC. The required IPs/FQDNs are listed under SIP Signaling: FQDNs in the Direct Routing planning documentation.
3. If calls reach the SBC but no connection is established
   • When the SBC receives SIP OPTIONS from Teams but returns 4xx–6xx failures, the issue is on the SBC side or upstream:
     • Another telephony device on the same network could be generating the SIP failure → troubleshoot that device or contact its vendor.
     • The PSTN provider could be sending failures (commonly SIP 403 or 404) → contact the PSTN provider.
     • If neither applies and the cause is unclear → contact the SBC vendor for detailed SIP trace analysis.
4. Validate user voice routing (if only some users affected)
   • If some users can call and others cannot, but the SBC works for at least some calls, check:
     • Users have correct licensing and Direct Routing enablement.
     • Their Online Voice Routing Policy has a pattern that matches the dialed number and points to an enabled gateway.

These steps should show whether the problem is that Teams is not sending calls to the SBC at all (gateway disabled or SIP blocked) or that the SBC/PSTN path is rejecting them.

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References:

• Issues that affect outbound direct routing calls