PDN (Packet Data Network)

A Packet Data Network is any external IP network, public internet, IMS, enterprise APN, MEC application network, that a mobile subscriber connects to via the PGW (4G) or UPF (5G). Each PDN is identified by an APN, and per-PDN policy controls QoS, charging, and security boundary enforcement at the gateway.

Categories: Core NetworkIdentity and SubscriberOperations and Business

PDN in context

The mobile core carries subscriber sessions, mobility and policy. 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.

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

To place PDN in the wider telecom-security picture, review BSF, ARPU, Confidentiality, Cryptography, CSPM and DRP — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.