URSP (UE Route Selection Policy)

Also known as: UE Route Selection Policy

URSP is the 3GPP policy set (TS 23.503) delivered by the PCF to a 5G UE that tells the UE which PDU session, slice (S-NSSAI), DNN and access to use for a given application or traffic descriptor. Correct URSP handling is fundamental to slice isolation: a UE that ignores or misapplies URSP can leak traffic across slices or use an unintended DNN.

Categories: Core NetworkProtocols and StandardsInternet and Routing

URSP 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.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place URSP in the wider telecom-security picture, review AF, 3G, 3GPP, AES, A5/1 and A5/3 — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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