Update Bearer Request and Response

Feature Summary and Revision History

Summary Data

Table 1. Summary Data

Applicable Product(s) or Functional Area

cnSGW-C

Applicable Platform(s)

SMI

Feature Default Setting

Enabled - Always-on

Related Documentation

Not Applicable

Revision History

Table 2. Revision History

Revision Details

Release

First introduced.

2020.04

Feature Description

In this release, cnSGW-C supports only relay of update bearer request (which can contain TFT change, QCI change or APB – AMBR change) from PGW towards MME. When MME sends response to cnSGW-C, it relays update bearer response towards PGW.

This release doesnt support signaling towards User Plane.

Standards Compliance

The Update Bearer Request and Response Support feature complies with the following standards:

  • 3GPP TS 23.401

  • 3GPP TS 23.214

  • 3GPP TS 29.274

  • 3GPP TS 29.244

How it Works

This section describes how this feature works.

Call Flows

This section describes the key call flow of Update Bearer Request and Response feature.

Figure 1. Bearer Request/Response without UP Signaling Call Flow
Table 3. Bearer Request/Response without UP Signaling Call Flow Description

Step

Description

1

MME sends Create Session Req to S11-GTP-EP with TEID value as zero.

2

Transaction E-T1 started.

S11-GTP-EP sends Create Session Req to SGW-Service POD.

3, 4

Transaction S-T2 started.

SGW-Service POD sends Allocate ID to Node-Mgr and receives response from it.

5, 6, 7

SGW-Service POD reads Node-Mgr updated UPF cache and performs UPF selection.

SGW-Service POD sends Sx Est Req to PFCP-EP.

Transaction P-T3 started.

SGW-Service POD receives Sx Est Rsp from PFCP-EP.

8, 9

Transaction P-T3 completed.

SGW-Service POD sends Create Session Req to S5-SGW-EGRESS-GTP-EP.

Transaction E-T4 started.

SGW-Service POD receives Create Session Rsp from S5-SGW-EGRESS-GTP-EP.

10, 11, 12

Transaction E-T4 completed.

SGW-Service POD sends Sx Mod Req to PFCP-EP.

Transaction P-T5 started.

SGW-Service POD receives Sx Mod Rsp from PFCP-EP.

12

Transaction S-T2 ans P-T5 completed.

SGW-Service POD sends Create Session Rsp to S11-GTP-EP.

13

Transaction E-T1 completed.

S11-GTP-EP sends Create Session Rsp to MME.

14

SGW-Service POD sends Create Session to DB.

15

MME sends Modify Bearer Req with TEID value to S11-GTP-EP.

16

S11-GTP-EP routes MBReq with TEID to the exact SGW-Service POD.

S11-GTP-EP sends Modify Bearer Request SGW-Service POD.

17

Transaction S-T2 completed.

SGW-Service POD sends Sx Mod Req to PFCP-EP.

18

Transaction P-T3 started.

SGW-Service POD receives Sx Mod Rsp from PFCP-EP.

19

Transaction P-T3 completed.

SGW-Service POD sends Sx Mod Rsp to S11-GTP-EP.

20

Transaction S-T2 completed.

SGW-Service POD sends Update Session to CDL.

21

S5-SGW-EGRESS-GTP-EP sends Update Bearer request with TFTs and APN AMBR to SGW-Service POD.

22, 23

Transaction S-T3 completed.

SGW-Service POD sends Update Bearer Request to S11-GTP-EP.

S11-GTP-EP forwards Update Bearer Request to MME.

24, 25

MME sends Update Bearer Rsp to S11-GTP-EP.

S11-GTP-EP forwards Update Bearer Rsp to SGW-Service POD.

26

SGW-Service POD forwards Update Bearer Rsp to S5-SGW-EGRESS-GTP-EP.

27

SGW-Service POD sends Update Session to CDL.