Have found example configuration for S-CSCF, I-CSCF and P-CSCF in Kamailio repository, and a S-CSCF module for the registered user data, but no recent updates. Wondering if anyone can share insights into how widely it has been used, or interops done in say telco networks with it ?

Does it handle third-party registrations, is it actually able to do a Cx interaction with HSS ? Finally, how have  these components that make up the IMS-core from SIP signaling standpoint, been tested ? Are there any signaling only test harnesses ?

cheers,

Jay