What the AMF does
The AMF is the main 5G Core control-plane contact for the access network. It terminates NAS signalling from the UE, manages registration and connection state, supports mobility and reachability, and coordinates access authentication with other functions.
How it relates to slicing
During registration, the AMF handles requested and allowed NSSAI information. It can use NSSF information and subscription context to determine which slice-related services are available and which AMF set is suitable.
What it does not do
The AMF does not forward user packets. User traffic follows the user plane through the RAN and UPF. It also does not single-handedly guarantee a slice SLA.
Standards note: this page is an explanatory summary. Precise procedures, services and information elements are defined in the applicable 3GPP specifications.