The OSS NAS Tools now support encoding/decoding of URSP (UE Route Selection Policy) information within a NAS message (3GPP TS 24.526 Release 16.8.0). URSP is a network slice feature that provides a way to manage network slice information for the UE.
The URSP messages are transported in the UE Policy Container of the Uplink/Downlink NAS Transport, RegistrationRequest, or ContainerEntryUL message type. In earlier versions of the NAS Tools, the container value was decoded as an octet string. The UE policy message can now be fully decoded into a UE Policy Management message structure/object.
The UE Policy Container contains a UE Policy Management message that can be one of the following types:
Manage UE Policy Command
Manage UE Policy Complete
Manage UE Policy Command Reject
UE State Indication
UE Policy Provisioning Request
UE Policy Provisioning Response
The decoding of the URSP message is done in two steps. In the first step, the top-level NAS message is decoded. In the next step, the UE Policy Container is decoded to a UE Policy Management message structure/object from its octet string value that was obtained from the first decoding step of the top-level message.
For more technical details, please review the URSP sample (nas_ursp) located under the samples/ directory of the OSS NAS Tools.
