Change Notification Request Call Flow

This section describes the change notification request and the response call flow.

Change Notification Request Call Flow
Change Notification Request Call Flow Description

Step

Description

1

The MME sends a Create Session Request towards GTP-EP(S11).

2

The GTP-EP(S11) forwards the Create Session Request to the SGW-SVC.

3

The SGW-SVC sends the Sx Establishment Request to the UPF.

4

The UPF responds to the request with the SX Establishment Response directed towards the SGW-SVC.

5

The MME and the PGW establish the sessions and start exchanging data.

6

The MME and the PGW create the dedicated bearer and start exchanging data.

7

The MME sends the Change Notification Request to the GTP-EP.

8

The GTP-EP forwards the Change Notification Request to the SGW-SVC.

If ULI or UCI changes are valid in the connection request (CNREQ), the PDN is updated.

The GTP-EP sends the Sx Modification Request with the URR query after checking the secondary RAT usage.

9

The SGW-SVC sends the Sx Modification Request with the URR query to the Proto-SXA.

10

The Proto-SXA forwards the Sx Modification Request with the URR query to the UPF.

11

The UPF responds to the request with the Sx Modification Response, with the usage report to the Proto-SXA.

12

The Proto-SXA forwards the Sx Modification Response with the usage report to the SGW-SVC.

13

The SGW-SVC sends the Change Notification Request to the GTPC-S5.

14

The GTPC-S5 forwards the Change Notification Request to the PGW.

15

The PGW responds with the Change Notification Response to the GTPC-S5.

16

The GTPC-S5 forwards the Change Notification Response to the SGW-SVC.

17

The SGW-SVC sends the Change Notification Response to the GTP-EP(S11).

18

The GTP-EP(S11) forwards the Change Notification Response to the MME.