Core-Network

Intro Signaling System No. 7 (SS7) is a global suite of protocols that defines how network elements in a public switched telephone network (PSTN) exchange information to route calls. Developed in the 1970s, it moved the industry away from “in-band” signaling—where control tones shared the same path as voices—to a much faster “out-of-band” system. By using a dedicated digital channel for signaling, SS7 allows for nearly instantaneous call setup and prevents the legacy “phreaking” fraud that once plagued phone lines. ...

Understanding MME States in the EPC: EMM vs. ECM In the LTE Evolved Packet Core (EPC), the Mobility Management Entity (MME) is the brain of the control plane. To manage a device (UE) efficiently, the MME uses two parallel state machines: EPS Mobility Management (EMM) and EPS Connection Management (ECM). Think of it this way: EMM determines if you are “checked in” to the network, while ECM determines if you are “actively talking” to it. ...