PDU Session Establishment Call Flow
This section describes the call flow of the PDU session establishment.

Step | Description |
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1 |
If the UE requests to establish an always-on PDU session, the UE includes an ‘Always-on PDU Session Requested’ IE in the PDU Session Establishment Request message. |
2 |
The SMF checks the DNN profile to determine whether the “always-on” support is enabled. |
3 |
The SMF includes an ‘Always-on PDU Session Indication’ in the PDU Session Establishment Accept message if any one of the following is true:
|
4 |
The SMF does not include an ‘Always-on PDU Session Indication’ only when both these conditions are true:
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