MBR Optimization Call Flow
This section describes the high-level MBR Optimization call flow for idle↔active transition.

Step |
Description |
---|---|
1 |
MME sends Release Access Bearer (RAB) request to UDP proxy. |
2 |
UDP Proxy forwards RAB Request to GTP-S11. |
3 |
GTP-S11 forwards RAB Request to SGW-service. |
4 |
SGW-service sends Sx Modify List for all PDNs to PFCP. |
5 |
SGW-service prepones RAB Response. |
6 |
GTP-S11 sends RAB Response to UDP Proxy. |
7 |
UDP Proxy sends RAB Response to MME. |
8 |
PFCP sends and receives Sx Modify for IMS APN to and from UPF. |
9 |
PFCP sends and receives Sx Modify for Data APN to and from UPF. |
10 |
PFCP sends Sx Modify Response List for all PDNs to SGW-service. |
11 |
MME sends Service Request MBRequest for IMS PDN to UDP Proxy. |
12 |
UDP Proxy forwards Service Request MBRequest for IMS PDN with TEID cache data to GTP-S11. |
13 |
GTP-S11 sends MBResponse for IMS PDN to UDP Proxy. |
14 |
UDP Proxy forwards MBResponse for IMS PDN to MME. |
15 |
MME sends Service Request MBRequest for Data PDN to UDP Proxy. |
16 |
UDP Proxy sends Service Request MBRequest for Data PDN with TEID cache data to GTP-S11. |
17 |
GTP-S11 sends MBRequest List for IMS and Data PDNs to SGW-service. |
18 |
SGW-service sends Sx Modify List for IMS and Data PDN to PFCP. |
19 |
PFCP sends and receives Sx Modify for IMS PDN to and from UPF. |
20 |
PFCP sends and receives Sx Modify for Data PDN to and from UPF. |
21 |
PFCP sends Sx Modify Response List for IMS and Data PDN to SGW-service. |
22 |
SGW-service sends ULI Update MBRequest List for IMS and Data PDN (Async Notification) to GTP-S5. |
23 |
SGW-service sends MBResponse List for Data PDN to GTP-S11. |
24 |
GTP-S11 sends MBResponse for Data PDN to UDP Proxy. |
25 |
UDP Proxy forwards MBResponse for Data PDN to MME. |
26 |
GTP-S5 sends and receives ULI Update MBRequest for IMS PDN to and from PGW. |
27 |
GTP-S5 sends and receives ULI Update MBRequest for Data PDN to and from PGW. |
28 |
SGW-service sends DDN Request to GTP-S11. |
29 |
S-11 forwards DDN Request to UDP Proxy. |
30 |
UDP Proxy forwards DDN Request to MME. |
31 |
MME sends Service Request MBRequest to UDP Proxy. |
32 |
UDP Proxy sends Service Request MBRequest with TEIDCacheData to GTP-S11. |
33 |
GTP-S11 sends MBResponse List for IMS and Data PDNs to SGW-service. |
34 |
MME sends Service Request MBRequest for IMS PDN to UDP Proxy. |
35 |
UDP Proxy Service Request MBRequest for IMS PDN with TEID cache data to GTP-S11. |
36 |
GTP-S11 sends MBResponse for IMS PDN to UDP Proxy. |
37 |
UDP Proxy sends MBResponse for IMS PDN to MME. |
38 |
SGW-service sends DDN Request to GTP-S11. |
39 |
GTP-S11 forwards DDN Request to UDP Proxy. |
40 |
UDP Proxy sends internal DDN acknowledgement to GTP-S11. |
41 |
MME sends Service Request MBRequest for Data PDN to UDP Proxy. |
42 |
MME sends Service Request MBRequest for Data PDN with TEID cache data to GTP-S11. |
43 |
GTP-S11 sends MBRequest List for IMS and Data PDNs to SGW-service. |