VoWiFi (Voice over Wi-Fi)

Voice over Wi-Fi delivers carrier voice service through the IMS over a Wi-Fi access network, using an ePDG and IPsec tunnel back into the operator core. Subscribers benefit from indoor coverage in poor-signal areas; security depends on IPsec authentication with EAP-AKA, integrity of the ePDG, and proper IMS access controls. VoWiFi reuses the same MSISDN and IMS identity as VoLTE/VoNR.

Categories: Radio Access NetworkCore NetworkIdentity and Subscriber

VoWiFi in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

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.

To place VoWiFi in the wider telecom-security picture, review Confidentiality, Encryption, FDD, MNO, TMSI and UPF — 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.