Description

Caller ID Number (CID) is a telecommunications feature that provides the recipient of an outbound call with the phone number of the caller. When you make a call, this service transmits your phone number, allowing the callees to see who is calling before they answer. This feature enhances communication by enabling callee to screen incoming calls, improving their ability to decide whether to accept or decline a call based on the displayed number.

The following SIP headers in SIP INVITE are accepted for Caller ID, listed in order of priority (with 1 being the highest and 4 the lowest):

1. P-Preferred-Identity User
2. P-Asserted-Identity User
3. Remote-Party-Id User
4. FROM User

When both the FROM User header and the PAI header are present in the SIP INVITE, the PAI header takes precedence and is displayed as the Caller ID number due to its higher priority.

The example below displays an anonymous call, the From headers carry <sip: Anonymous@10.243.118.38>. The UCM simply transmits whatever it receives from the SIP Service Provider.

Manipulate Caller ID Display

To modify the Caller ID display, you can go to UCM > Inbound Route > CallerID Setting. Here, you can enable ‘Set CallerID Info‘ and specify the ‘Caller ID Name’ and ‘Number’. This option establishes a fixed caller ID name and number for all calls that pass through this inbound route. The Remote-Party-ID header will be updated and displayed on Callee’s phone.