RFC 9796: SIP Call-Info Parameters for Rich Call Data

This document specifies a usage of the SIP Call-Info header field that incorporates Rich Call Data (RCD) associated with the identity of the originating party in order to provide to the terminating party a description of the caller (including details about the reason for the session). RCD includes information about the caller beyond the telephone number (such as a calling name, logo, photo, or jCard object representing the caller), which can help the called party decide how to handle the session request. This document defines three new parameters 'call-reason', 'verified', and 'integrity' for the SIP Call-Info header field and also a new token ("jcard") for the 'purpose' parameter of the Call-Info header field. It also provides guidance on the use of the Call-Info 'purpose' parameter token, "icon".