VoLTE (Voice over LTE)

Voice over LTE delivers voice and video calls over the LTE data bearer using the IMS as the call-control fabric, replacing the legacy circuit-switched MSC. VoLTE supports HD voice, faster call setup, and concurrent voice plus high-speed data. Its security depends on the integrity of IMS components (P/I/S-CSCF), proper SIP authentication, SRTP for media, and IPsec/TLS on the SIP signalling. Misconfigurations have historically allowed IMSI disclosure and call-data extraction, so VoLTE security testing is an established discipline.

Categories: Core NetworkSignalingIdentity and Subscriber

VoLTE 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.

Signaling protocols carry the control-plane instructions that set up calls, register subscribers, hand over sessions 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 FS.11 / FS.19 / FS.20 as a top-tier telecom risk.

To place VoLTE in the wider telecom-security picture, review MSC, IAMF, SMS, VoNR, VoWiFi and OTP Bypass Attacks.

Related terms

Equipment

IMS core (CSCF, TAS, MRF, MGCF, BGCF)

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