Applies To

Call2Teams - Customers


Users see a 403 Forbidden error in response to difficulties placing calls.

Microsoft also returns a Q.850 response.


Q.850 responses are similar to SIP signalling codes, in that they provide reason codes which may also carry verbose detail on the cause for the rejection.


Further diagnostics may be necessary to establish the reason why Microsoft are rejecting a call.

Where possible the service will offer suggestions as to how these can be resolved.

Example Q.850 Issue

Reason header: Q.850 ;cause=63 ;text="9810e5a9-667c-4513-8d3a-5d83503e1c71;Current call site state prevents fork to this entity."

In the above example, the Q.850 response code has cause 63, "Service or option not available, unspecified". While implementations of causes and cause handling vary widely, the verbose detail given provides more information on this cause: Something in the call chain is preventing the call being forked to the attempted destination.