vSMF Modify Session Procedure

This section provides details about the modify session procedure for vSMF.

vSMF Modify Session Call Flow
vSMF Modify Session Call Flow Description

Step

Description

1

The AMF sends the request from the UE as an Sm Context Update message to the vSMF.

2

The vSMF uses the reference that the hSMF returned during creation of the message. It posts the relevant parts of the message to the hSMF. The hSMF responds to the message.

3

The hSMF sends an update request to the vSMF. This message contains the N1 and N2 messages that is sent to the gNB or UE as a part of the request message.

4

The vSMF combines the information from the hSMF and creates the N1 and N2 payloads for the UE and gNB. It then adds these to the response for the original request from the AMF.

5

The AMF relays the N2 response to the gNB.

6

If there are changes to the UPF due to the modification requested by the UE and accepted by the network, for example, addition or deletion of flows, the vSMF updates the UPF with these changes.

7

The vSMF notifies the CHF of any charging triggers for the changes applied to the UPF.

8

The vSMF acknowledges the N2 message from the AMF with a 200 OK message.

9 The AMF transfers the N1 payload from the UE and the vSMF acknowledges it.
10

The vSMF responds to the request from the hSMF for session modification.