I am running an Asterisk 17.6.0, and I have a specific request to directly reject some calls with SIP 603 release cause.
I have the dialplan configure as:
exten => _01234X!,1,Hangup(21)
But, 21 is mapped to 401, 403, 407, 603 (according to Hangup Cause Mappings - Asterisk Project - Asterisk Project Wiki), and asterisk is actually returning 403.
How can I set it to return 603, or any other cause If needed?