NSSF
Network Slice Selection Function
The NSSF can be used by the AMF (Core Access and Mobility Management Function) to assist with the selection of the Network Slice instances that will serve a particular device. As such, the NSSF will determine the Allowed NSSAI (Network Slice Selection Assistance Information) that is supplied to the device. Moreover, the NSSF may be used to allocate an appropriate AMF if the current AMF is not able to support all network slice instances for a given device.