PFCP (Packet Forwarding Control Protocol)

Also known as: Packet Forwarding Control Protocol, Sx, N4 Protocol

PFCP is the 3GPP protocol (TS 29.244) between control and user plane functions on the Sxa/Sxb/Sxc interfaces (EPC CUPS) and the N4 interface in 5G. It lets the SMF program forwarding, QoS and usage-reporting rules into the UPF, and lets the SGW-C program the SGW-U. Exposed PFCP endpoints are a critical attack surface: manipulation can redirect user traffic, disable lawful intercept or exfiltrate session data.

Categories: Core NetworkProtocols and Standards

PFCP 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.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place PFCP in the wider telecom-security picture, review AES, Conformance Testing, EIR, MEC, NESAS and OpenSSL — 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.