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 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.

Signaling protocols carry the control-plane messages that set up calls, register subscribers 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 as top-tier telecom risk.

To place Rx Interface in the wider telecom-security picture, review 5G SA, 5G SBA, ACL, AMF, Base Station (BS) and Capacity Planning — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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