EPS Fallback
In telecommunications, EPS Fallback is a 5G voice procedure in which a UE attached to 5G is moved to LTE (EPS) for the duration of a voice call when VoNR is not available. It allows operators to deploy 5G data while continuing to rely on VoLTE for voice.
Categories: Radio Access Network
EPS Fallback in context
The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.
To place EPS Fallback in the wider telecom-security picture, review CSFB, SRVCC, EDGE, DSS, GBR / Non-GBR Bearers and Diameter.
Related terms
Related topic hubs
- VoLTE Security IMS/VoLTE signaling risk: SIP, IMS-AKA, media plane attacks.
- IMS Security Training Training on IMS, VoLTE/VoNR, SIP and RCS security.
- Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
- Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
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.