Teams calls failing, "Code: InvalidRequest Message" in Integration menu.

[Awjvail]

Hi there,

Having some issues getting Teams direct routing going.

Issue: Teams calls fail immediately upon dialing.

The following error is showing in the Microsoft 365 Integration menu within 3CX:

• Real Time Notifications to Microsoft 365 changes will not work because it seems that HTTPS port forwarding is not configured. This means that when changes occur, they will not be updated real time. A synchronization will still occur every night.
• Code: InvalidRequest Message: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. Inner error: AdditionalData: date: 2021-10-07T19:46:44 request-id: bb7cbf1f-1300-40bb-b542-710c34b177f6 client-request-id: bb7cbf1f-1300-40bb-b542-710c34b177f6 ClientRequestId: bb7cbf1f-1300-40bb-b542-710c34b177f6

I have verified the following:
- Dial plan etc. is loaded
- User has a phone system license
- User has the correct 3CX policies applied in the Teams admin panel, as per the PowerShell script.
- Valid certificate for teams.mydomain.com is applied within 3CX
- Port 5001 is open and I can access https://3cx.mydomain.com:5001 and https://teams.mydomain.com:5001 from outside
- Port 5062 is open, verified with several "port forwarding checker" utility sites.
- Port 443 is open, verified with several "port forwarding checker" utility sites.

Any ideas?

 

[Awjvail]

Update, nevermind, the error was fixed by ensuring the certificate on my main 3CX FQDN was working.

Calls are now going through, BUT I don't receive any audio either incoming or outgoing.

This is for both internal calls and external calls. Where do I start with this one?

 

[Charles_3CX]

For this start by running the firewall checker on the 3cx system to ensure all the correct inbound ports are forwarded then check this guide for the specific outbound port requirements https://www.3cx.com/docs/microsoft-teams-integration-faqs/#h.hoorao7nd0fk

 

[Awjvail]

Firewall test comes back as expected

Audio works when calling from a regular phone, or when using the 3CX mobile app (incl. from external) but not with Teams.

 

[NickD_3CX]

Is the 3CX Server behind a double NAT by any chance? Also is the IP address in the range defined by RCF1918 (10.0.0.0/8/ 192.168.0.0/16, etc)?

A few other cases that we have heard of, they were being caused by routing issues on the network.

Also could the Firewall be blocking any UDP ports in the 9000-10999 range from/to specific IPs?