N3IWF (Non-3GPP Interworking Function)

N3IWF 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.

Security controls in telecom span signaling firewalls (SS7/Diameter/GTP screening at the network edge), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both the packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36 and, in Europe, NIS2 sectoral rules.

To place N3IWF in the wider telecom-security picture, review ePDG, TNGF, EAP-AKA′, N8, N12 and Inter-Network Function Authentication.

Related terms

• ePDG
• TNGF
• EAP-AKA′
• N8
• N12
• Inter-Network Function Authentication
• Mediation Device (Lawful Interception)
• Network Exposure Function (NEF)

Equipment

Wi-Fi and non-3GPP access gateways (ePDG, N3IWF, TWAG, TNGF)

• ePDG
• TNGF
• VoWiFi

Articles in the P1 mobile network security guide

Related topic hubs

• 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.
• 5G NEF Security Network Exposure Function security in the 5G core.
• 5G Penetration Testing Pentesting the 5G core, SBA, SEPP, and gNB interfaces.
• 5G Security Training Training on 5G core, SBA, N32, SUCI and radio security.

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.