I have a SIP trunk between our vMCD and our Dispatch system (Intrado Viper). We also have carrier SIP for external calling. When our dispatchers call out from their system to the external SIP trunks the primary extension 7223 shows up as the caller ID. I have set up CPN substitution on both circuits so the main line shows up instead of the extension and have the default outbound caller ID on the SIP circuit set to that same number. No matter what I do though the caller ID is still wrong.
Some history: We used to have PRI’s as outbound and had the same issue until we set the PRI’s default to be the dispatch main line and we set all other numbers in the system with CPN substitution to override it. Now that we have all SIP I need another solution.
The 2 systems are being split in February but until then I need them to play nice so our dispatchers can call out and not be ignored as spam.