Applies To

Call2Teams - Customers


Outbound calls fail with a 401 Error.

This affects Trunk users and has been noted where the trunks do not challenge Auth but rely on IP addresses.


The error will appear to be a 401 Auth challenge coming from the trunk.

The Service-facing SBC may convert this to a 403 Forbidden message (bad auth) and pass this back to the Teams caller.

Explanation of Behaviour

This occurs where the SBC IP address has changed and the client maintains an allow list of SBC IP addresses. The Trunk does not recognise the address from which the call is being sent. 

The SBC knows this is not a regular Auth challenge so does not send a REINVITE. Instead, a 403 Forbidden error is sent.


The client must add the SBC IP Addresses to their allow lists.