For analog telephones, the caller ID information (caller’s number and name) is sent to the telephone as a burst between the first and second rings. When a call is received over an ISDN trunk in North America, the caller information can be delivered either in the SETUP message or in a subsequent FACILITY message.
The display for IP and digital telephones can be updated with the caller information, based on the US NI Delayed Calling Name Update field on ISDN Trunk Group screen.
For analog caller ID telephones, the Delayed Caller ID Alerting for Name Display Update feature enables the following:
Communication Manager waits for the FACILITY message before delivering an incoming call to the called user.
Administer the time to wait for the FACILITY message which includes the caller information.
If no FACILITY message is received before the timer expires, the called analog telephone rings without displaying the caller ID information.
