Gateway connecting UE to external packet data networks, allocates IP addresses.
Description
The PDN Gateway (P-GW) is the edge router between the EPC and external packet data networks (PDNs) such as the Internet or IMS. It allocates IP addresses to UEs and enforces QoS and charging policies.
The P-GW performs policy enforcement, per-user packet filtering, charging support, and lawful interception. It is the anchor point for mobility between 3GPP and non-3GPP accesses.
Purpose & Motivation
The P-GW provides the connection point to the external world and was designed to:
- Provide IP address allocation (IPv4/IPv6) - Enforce operator policies via PCEF - Support both 3GPP and non-3GPP access networks - Enable seamless mobility across different access technologies
Key Features
- ✓IP address allocation
- ✓Policy enforcement (PCEF)
- ✓Per-user packet filtering
- ✓Charging support (online/offline)
- ✓Mobility anchor for non-3GPP