Collapsed Call Attach with SGW-Service to SMF-Service Configuration Call Flow

This section describes the Collapsed Call Attach with SGW-Service to SMF-Service Configuration call flow.

Collapsed Call Attach with SGW-Service to SMF-Service Configuration Call Flow
Collapsed Call Attach with SGW-Service to SMF-Service Configuration Call Flow Description

Step

Description

1

MME sends the Create Session Request to GTP-S11.

2

GTP-S11 sends the Create Session Request to SGW-SRV.

3

SGW-SRV sends the Sx Session Establishment Request to PFCP.

4

PFCP sends the Sx Session Establishment Request to cnSGWu/SMFu.

5

cnSGWu/SMFu sends the Sx Session Establishment Response to PFCP.

6

PFCP sends the Sx Session Establishment Response to SGW-SRV.

7

SGW-SRV sends the Create Session Request to SMF. The Service Short Circuit is set to TRUE.

8

SMF sends the Create Session Response to SGW-SRV.

9

SGW-SRV sends the Sx Session Modify Request to PFCP.

10

PFCP sends the Sx Session Modify Request to cnSGWu/SMFu.

11

cnSGWu/SMFu sends the Sx Session Modify Response to PFCP.

12

PFCP sends the Sx Session Modify Response to SGW-SRV.

13

SGW-SRV sends the Create Session Response to GTP-S11.

14

GTP-S11 sends the Create Session Response to MME.

For a collocated subscriber, when SGW-SRV receives:

  • Modify Bearer Request and Delete Session Request from the MME, the SGW-SRV communicates these messages to the SMF service.

  • Create Bearer Request, Update Bearer Request, and Delete Bearer Request from the SMF, the SGW-SRV communicates the response messages for these request messages to the SMF service.