When an application uses SIP registrar support, the telephony engine will notify the application software regarding the status of registrar operations. For registration events to be sent to the application, the application software must enable registration services by calling the EnableSipRegisterServer API procedure.
After application software enables registration services, the telephony engine can send any of the following global events to application software:
SipRegisterAuthorizationError
SipRegisterErrorBadCredentials
SipRegisterNetworkError
SipRegisterError
SipUnRegisterTrying
SipUnRegisterAuthorizationError
SipUnRegisterErrorBadCredentials
SipUnRegisterNetworkError