I know this probably sounds like a silly question, but understand that when using survivability.tcl, that TCL file and service on the dial-peer is what actually plays "critical_error.wav" or the like... When you are *not* using survivability, CVP sends a REFER to the Originator with the error DN (default is 92929292).
We can see this REFER sent to the originating gateway, and we can even match the pattern to a dial-peer (though it must be configured as a destination-pattern and not an incoming called-number as shown in the documentation)...but we cannot get "cvperror.tcl" and the associated "cvperror" service to actually work.
So after fruitless searching, I'm convinced that this might not actually work at all, or I'm missing a configuration setting somewhere (I'm hoping that is the case, actually).
Can anyone actually tell me they have a system that shows the error DN being passed to the gateway, matching the dial-peer with configured service, and actually calling cvperror.tcl to play the critical_error.wav?
The second part is, if the answer is "yes", are you using survivability and/or CUPS as a SIP Proxy?