Rx Interface (Rx Diameter Reference Point)

The Rx interface (3GPP TS 29.214) is the Diameter reference point between the IMS P-CSCF (as AF) and the PCRF/PCF, used to signal application-level QoS and charging requirements (media type, bandwidth, priority) into the policy plane. In VoLTE it is what turns SIP session negotiation into dedicated bearers with the right 5QI/QCI.

Categories: Core NetworkSignalingOperations and Business

Rx Interface 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 Rx Interface in the wider telecom-security picture, review PCRF, Rf / Ro, N2, N9, PCF and N3.

Related terms

Related topic hubs

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.