PGW (Packet Data Network Gateway)

The Packet Data Network Gateway is the 4G EPC element that connects subscriber data sessions to external networks (internet, IMS, enterprise APNs). It allocates IP addresses, enforces per-bearer QoS, applies charging via the OCS/PCRF, and performs lawful interception. The PGW is the user-plane border between the trusted mobile core and external networks, and its 5G equivalent is the UPF; both require careful filtering and DDoS protection because they are reachable from untrusted networks.

Categories: Core NetworkIdentity and SubscriberThreats and Attacks

PGW in context

The mobile core is where subscriber sessions, mobility and policy live. 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. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) are the anchor for authentication, charging, lawful interception and fraud analytics. Any protocol or interface that leaks a permanent identifier is treated as a serious privacy defect, which is why 5G introduced SUCI concealment on the air interface.

To place PGW in the wider telecom-security picture, review GMLC, PDN, GMSC, MSC, UPF and UDR.

Related terms

Equipment

User plane and packet gateways (UPF, PGW, SGW, GGSN)

Articles in the P1 mobile network security guide

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