Creating a sip registrar configuration element enables the Oracle Communications Core Session Manager (OCCSM) to act as a SIP registrar. When registration functionality is enabled, the OCCSM actually registers endpoints rather than only caching and forwarding registrations to another device. OCCSM registry services are enabled globally per domain, not on individual SIP interfaces or other remote logical entities.

On receiving a REGISTER message, the OCCSM checks if it is responsible for the domain contained in the Request-URI as defined by the domains parameter and finds the corresponding sip registrar configuration. This is a global parameter—all messages are checked against all sip registrar domains. Thus you could create one sip registrar configuration element to handle all .com domains and one sip registrar configuration element to handle all .org domains. The OCCSM begins registrar functions for all requests that match the configured domain per sip-registrar configuration element.

A UA is considered registered once a SAA assignment is received from the HSS, after which the OCCSM sends a 200 OK message back to the registering UA.