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5G • Core Network

Nnssf Interface

NSSF Service-Based Interface

RESTful service interface exposed by NSSF for selecting authorized Network Slice Instances.

Technical Explanation

Nnssf_NSSelection allows the AMF to query NSSF during registration or PDU session establishment. NSSF evaluates the UE's subscription and location to return the Allowed NSSAI, target AMF Set, and candidate Network Slice Instances (NSIs).

Key Functions

  • Selects appropriate Network Slice Instances (NSIs) for registering UEs
  • Determines Allowed NSSAI and Configured NSSAI for current location
  • Directs AMF redirection when slice requires specific AMF instance
Specifications
3GPP TS 29.531
Interfaces
NnssfSBI

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