I am having and issue I hope someone can help with..

I have calls that often come in that need to be blocked. We wish to do this without answering the call. The issue is our carriers have fail over servers and will try sending the call from each when we block the call.

If we send a hangup with a Sip 401 they will stop the route advance on their end.

The issues is we have been sending a hangup/cause code 21 (Call rejected)
But they are receiving a 403 Forbidden..

Is there any hangup code that we can send that will reply a 401.. We see the 401 on the inbound is converted to a cause code 21 but we do not see any cause codes listed to send a 401 out. Please advise as this a becoming an issue for us as we have multiple vendors expecting a 401 not a 403

Any assistance is appreciated.

Thank you. Bryant