5G • Core Network
UDR
Unified Data Repository
The centralized database in 5GC that stores subscription data, policy data, structured exposure data, and application data.
Technical Explanation
The UDR acts as the cloud-native database repository for the entire 5G Core. By decoupling data storage from compute logic, NFs like UDM, PCF, and NEF operate statelessly. The UDR exposes standard RESTful CRUD APIs (Nudr) over HTTP/2 with JSON payloads, enabling automated database clustering, geo-redundancy, and rapid recovery without losing session or subscription state.
Key Functions
- Centralized storage of subscriber profiles for UDM
- Storage of policy rules and subscription-to-policy bindings for PCF
- Storage of exposure and application data for NEF
- Decoupling state from compute to enable stateless NF microservices
Specifications
3GPP TS 23.501, TS 29.504
Interfaces
Nudr (SBI to UDM, PCF, NEF)
Related 5G Concepts
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