Calls failing with 499 "Caller is Forbidden" and "603 Decline" errors.

[bradcoats]

Hello!

I have been attempting to configure Microsoft Teams Direct Connect to connect 3CX to our Microsoft Teams environment. I've reviewed the online guides and several forum posts multiple times and have the configuration that matches my understanding of requirements. However, I am unable to make calls between the systems.

When calling from Teams to 3CX (or externally via 3CX), I am getting 499 "Caller is Forbidden" errors and "603 Decline" statuses. I have attached a sample from a verbose Activity Log call.

When calling from 3CX to Teams, I am unable to see any incoming calls to the Teams extension.

Users do show mapped to Teams in the 3CX portal.


Phone numbers are entered in the Company field in Teams in E.164 format with extension (ie, +14055551234;ext=100).

I am currently self-hosting 3CX v20 U6 in Microsoft Azure's cloud service.

Any ideas/suggestions would be much appreciated.

 

[bradcoats]

I was able to resolve this issue after completing several steps. I believe I know what component made the difference, but I will outline the changes I made here in case that helps anyone else:

1. I enabled syncing of attributes with Microsoft 365. This helped make an issue or two more visible.
2. My telephoneNumber property in Active Directory was entered as +1##########;ext=###. When I enabled syncing, this came into the extensions as caller ID +1##########ext###, which was incorrect.
3. I updated all of my phone numbers to E.164 format without the extension. +1##########.
4. Resync Active Directory to Microsoft 365.
5. Resync 3CX from Microsoft 365.
6. Now the Microsoft Teams Integration user script from the 3CX Integrations section was generating properly. Previously, I'd had to manually edit this to get correct values.
7. I waited for about an hour to try again just to make sure everything was synced up and now the integration was working properly.

I'm fairly well convinced that the improperly formatted telephoneNumber property in Active Directory was the culprit, but I also turned on the remaining syncing options for 3CX, which revealed the issue. I hadn't previously been syncing all properties our system, but since it's working, I'm going to leave it alone.