PGW (PDN Gateway)
Updated
The PGW is the node of the 4G core network that connects devices to packet data networks: it allocates their IP address, applies the APN’s rules and forwards their traffic. Its role is defined in 3GPP TS 23.401; in 2G and 3G the equivalent is the GGSN, in 5G the SMF and UPF.
In practice
The private APN of an IoT fleet lives on the PGW: that is where its IP range and its routes towards the customer’s network are configured.