AMF vs MME
The MME (Mobility Management Entity) is LTE's single point for NAS termination, authentication orchestration, and session management. 5G splits those functions across AMF (mobility), SMF (session), and AUSF (authentication).
| Attribute | AMF | MME |
|---|---|---|
| Generation | 5G | 4G / LTE |
| NAS termination | AMF | MME |
| Session management | SMF (separate NF) | MME + SGW |
| Auth orchestration | AUSF via SEAF in AMF | MME direct |
| Interface style | SBA (HTTP/2 + OAuth) | Diameter S6a, S11 |
Verdict
The split is a security win — SMF and AUSF can be hardened and scaled independently. It is also a new lateral-movement surface: an attacker who lands in an AMF still needs to abuse SBA to reach subscriber keys, but SBA misconfiguration is the modern equivalent of Diameter trust.