IP multimedia subsystem (IMS) is a rising “platform for provisioning multimedia services (e.g., data, voice, and video) in 4G/5G systems. IMS “authentication is an essential methodology which grants legitimate users access to multimedia services. However, periodic re-validation of portable clients (mobile users) results in significant signalling traffic overhead due to the complete execution of the hectic procedure. Additionally, signalling protocol, for example, SIP overlooks clients' secrecy by leaving the unprotected public and private identities. In IMS every client entering from another network like UMTS or VOLTE needs to validate itself. Initial Registration of VoLTE is unprotected so that it can be used by any eavesdropper to get user identities and use them for future attacks. Along these lines, IMS core entities are influenced by high signalling that could be a source of the clog. The Session Initiation Protocol (SIP) is utilized as a part of IMS to build up and oversee sessions. The AKA algorithm is used for authentication of UE with servers.