5G core as cloud-native software — what NFs actually are

From Appliances to Services

Through 4G EPC, mobile core network functions were predominantly delivered as vendor appliances — closed hardware-software products from Ericsson, Nokia, Huawei, Cisco. The MME, SGW, PGW, and HSS each came as a black box with proprietary management interfaces, opaque internals, and pricing tied to subscriber count. 5G Core (5GC) reframes this completely. The 3GPP architecture for 5GC defines each function — AMF, SMF, UPF, NRF, AUSF, UDM, PCF, NEF, SEPP — as a Network Function exposing a Service-Based Interface. In implementation terms, an NF is a service: an HTTP/2 server with REST-like JSON…