Hi, IMS uses the SGi interface via the Gm interface (P-CSCF), which is available at Kamailio P-CSCF. You will have to configure P-CSCF discovery at the EPC (or the address of the P-CSCF directly at the UE). Sorry, I personally do not know a way to build a PCRF by Kamailio, but a PCRF is a diameter server, e.g. like a HSS. Kamailio has a lightweight diameter server module, maybe it can be used: https://www.kamailio.org/docs/modules/devel/modules/ims_diameter_server.html Just my two cent All the best Christoph From: sr-users <sr-users-bounces(a)lists.kamailio.org> On Behalf Of Pavithra Mohanraja Sent: Thursday, June 11, 2020 9:51 AM To: Kamailio (SER) - Users Mailing List <sr-users(a)lists.kamailio.org> Subject: [SR-Users] Kamailio IMS support Hi, I am trying to connect EPC with IMS. EPC is separate installation of comac-in-a-box . IMS is kamailio based. Do i have SGi interface configurations in kamailio so that i can establish communication between EPC and IMS. One more clarification. I have seen PCRF communication can be done using CDP .Is there any way to build PCRF as part of kamailio. Kindly help .. Thanks, Pavithra