Dedicated Bearer Update – Request Accepted Call Flow

This section describes the Default/Dedicated Bearer Update Procedure call flow.

Single Update Bearer Procedure supports:

  • Default bearer QoS/TFT change

  • Single/Multiple dedicated bearer QoS/TFT change

  • APN-AMBR change

Note

The call flow doesn't contain Sx Communication Messages related to the Default/Dedicated Bearer Update procedure.

Default/Dedicated Bearer Update (Single/Multiple Bearers) Support Call Flow
Default/Dedicated Bearer Update (Single/Multiple Bearers) Support Call Flow Description

Step

Description

1

The PGW sends the S5 Update Bearer Request with multiple bearer contexts to the GTPC-EP pod.

2

The GTPC-EP pod forwards the S5 Update Bearer request to the SGW-SVC pod.

3

SGW-SVC receives the S5 Update Bearer request and performs the following:

  • Creates a new transaction

  • Performs GTP validations

  • Triggers the S11 Update Bearer Request to the GTPC-EP pod

4

The GTPC-EP pod forwards the S11 Update Bearer Request to the MME.

5

The MME sends the S11 Update Bearer Response to the GTPC-EP pod.

6

The GTPC-EP pod forwards the S11 Update Bearer Response to the SGW-SVC pod.

7

SGW-SVC receives the S11 Update Bearer Response and performs GTP validations.

  • If: Any of the following is true, the SGW-SVC triggers Sx Modification Request to the PFCP-EP pod:

    • Bearer QoS (QCI/ARP) change

    • Transport Level Marking change

    • Fetch charging information for generating charging record ULI/TZ change

  • Else: The SGW-SVC sends the S11 Update Bearer Response to the PGW with the MME-provided S11 Update Bearer Response information.

8

The PFCP-EP pod forwards the Sx Session Modification Request to the UP.

9

The UP sends the Sx Session Modification Response to the PFCP-EP pod.

10

The PFCP-EP pod forwards the Sx Session Modification Response to the SGW-SVC.

The SGW-SVC receives the Sx Modification Response and performs the following:

  • Ends the transaction/procedure

  • Updates the CDL

  • Sends the S5 Update Bearer Response with cause as Accepted

11

The SGW-SVC sends the S5 Update Bearer Response to the PFCP-EP pod.

The PFCP-EP pod forwards the S5 Update Bearer Response to the GTP-EP pod.

12

The GTP-EP pod forwards the S5 Update Bearer Response to the UP.

The UP forwards the S5 Update Bearer Response to the PGW.