Real-time Transport Protocol

Real-time Transport Protocol (RFC 3550) carries audio and video streams over IP, typically on top of UDP, and is the media transport beneath SIP-based VoIP, IMS, VoLTE/VoNR, WebRTC, and most live-streaming systems. RTP itself provides timestamps, sequence numbers, and payload-type identification but no encryption; the secure profile SRTP (RFC 3711) adds confidentiality and integrity and is mandatory for carrier-grade voice services.

Categories: Radio Access NetworkSignalingSecurity Controls

RTP 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 RTP in the wider telecom-security picture, review RADIUS, SIP, TCP, IPsec, STIR/SHAKEN and N3.

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