VoIP (Voice over IP)

Voice over IP is the family of technologies for carrying real-time voice and multimedia over IP networks, using SIP for signalling and RTP/SRTP for media. VoIP underpins enterprise telephony, IMS-based VoLTE and VoNR, OTT calling apps, and wholesale interconnect. Its security threats include SIP registration hijacking, eavesdropping when SRTP is not used, INVITE flooding, and toll fraud via PBX compromise. Strong authentication, TLS for SIP, SRTP for media, and STIR/SHAKEN for caller-ID verification are the standard controls.

Categories: Radio Access NetworkSignalingRoaming and Interconnect

VoIP 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.

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 VoIP in the wider telecom-security picture, review IBCF, Firewall, Roaming Security Architecture, Certification Authority (CA), Interconnect Security Model and Inter-PLMN Security.

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