Create Session Request with Default Bearer EBI Call Flow

This section describes the Create Session Request with Default Bearer EBI call flow.

CSReq with Default Bearer EBI Call Flow
CSReq with Default Bearer EBI Call Flow Description

Step

Description

1

The MME sends a Create Session Request with TIED value as 0 to the GTPC-EP(S11).

2

The GTPC-EP(S11) forwards the Create Session Request with TIED value as 0 to the SGW-SVC.

3

The MME and the PGW process the Initial Attach PDN-1 with the default EBI-5 process.

4

The MME sends a Create Session Request TIED=0x80002002 with EBI-6 to the GTPC-EP.

5

The GTPC-EP forwards the Create Session Request TIED=0x80002002 with EBI-6 to the SGW-SVC.

6

The MME and the PGW establish the PDN-2 with default EBI-6 connection.

7

The MME and PGW complete the Create Dedicated Bearer with EBI-7 process.

8

If the SGW and MME are not in sync, the MME sends a Create Session Request with EBI-6 present in the SGW.

9

The GTPC-EP sends a CSReq TIED= 0x80002002 with EBI-6 to SGW.

10

After receiving the Create Session Request, the SGW-SVC performs the following-

  • Cleans up the PDN with default EBI=6.

  • Sends the Sx signalling to UPF to clear the session.

  • Performs the Create Session Request as a new PDN-Setup.

The SGW sends an Sx Session Delete Request on PDN-2 to Protocol-SXA.

11

The Protocol-SXA forwards a Sx Session Delete Request to SGW-UPF.

12

The SGW sends a Session Establishment Request to the Protocol-SXA.

13

The Protocol-SXA forwards a Sx Session Establishment Request to SGW-UPF.

14

The SGW-UPF responds to the Protocol-SXA with the Sx Session Establishment Response.

15

The Protocol-SXA sends the Sx Session Establishment Response to the SGW-SVC.

16

The SGW-SVC sends the Create Session Request TIED= 0x80002002 with EBI-6 to the GTPC-EP.

17

The GTPC-EP sends the Create Session Request TIED= 0x80002002 with EBI-6 to the PGW.

18

The PGW sends a Create Session Response to the GTPC-EP.

19

The GTPC-EP responds to the SGW-SVC with the Create Session Response.

20

The SGW-SVC forwards the response to the GTPC-EP.

21

The GTPC-EP sends the Create Session Response to the MME.