IPUPS (Inter-PLMN UP Security)

Also known as: Inter-PLMN UP Security, Inter PLMN User Plane Security

IPUPS is the 5G user-plane security function co-located with the UPF at the PLMN boundary that filters GTP-U traffic between the visited and home networks. Defined in 3GPP TS 33.501, it inspects and drops malformed or unauthorised GTP-U packets crossing the N9 interface, acting as a GTP firewall for 5G roaming user plane, the counterpart to SEPP on the control plane.

Categories: Core NetworkSignalingRoaming and Interconnect

IPUPS 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.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place IPUPS in the wider telecom-security picture, review GTP, GTP Firewall, GTP-U Smuggling, N9, FS.20 and FS.07: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

Related topic hubs

  • GTP Firewall GSMA FS.20 GTP-C/GTP-U screening on GRX/IPX borders.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
  • Roaming Security IPX/GRX interconnect risk, home-routed vs local-breakout, SEPP.
  • 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.

More from the TelcoSec Glossary

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