To understand EPC call flows, it's essential to familiarize yourself with key concepts, including:

In the world of mobile telecommunications, the "core network" is the brain. For 4G LTE, that brain is the . Without the EPC, a 4G antenna is just a metal pole emitting static. The EPC is responsible for authentication, billing, data routing, mobility, and seamless internet connectivity.

Acts as the local mobility anchor for data packets. It routes and forwards user data while the user moves between base stations (eNodeBs). Packet Data Network Gateway (P-GW):