AMF (Access and Mobility Management Function)

The Access and Mobility Management Function is the 5G control-plane network function that terminates the N1 NAS interface from the UE and the N2 interface from the gNB. It handles registration, connection management, mobility, and reachability, delegates authentication to the AUSF, and steers session requests to the appropriate SMF. The AMF is the 5G analogue of the 4G MME and is a high-value target because compromise enables tracking, denial of service, and forced bidding-down of security capabilities.

Categories: Radio Access NetworkCore NetworkSignaling

AMF in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

To place AMF in the wider telecom-security picture, review 5G SA, Base Station (BS), Capacity Planning, CAPEX, CSCF and Diameter — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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