Inter-MME Handover and Multi-PDN Handling Active-Idle Transition with ULI Change Call Flow

This section describes the Inter-MME Handover and Multi-PDN Handling Active-Idle transition with ULI change call flow.

Inter-MME Handover and Multi-PDN Handling Active-Idle Transition with ULI Change Call Flow

Repeat the steps provided in the Table 1 for PDN1 and PDN2 with respective transaction S-T1 and S-T2.

Inter-MME Handover and Multi-PDN Handling Active-Idle Transition with ULI Change Call Flow Description

Step

Description

1, 2, 3, 4

Received Modify Bearer request for both the PDNs (PDN1 and PDN2) at SGW-Service POD with new MME control F-TEID and new ULI. There is no eNodeB F-TEID present in Modify Bearer request.

  • Create a new transaction S-T1.

  • Validate Modify Bearer request.

5, 6

Received Sx Modification request from SGW-Service POD > PFCP-EP POD with APPLY ACTION as BUFFER.

Sx Modification request is forwarded to UP.

7, 8

Received Sx Modification response from UP > PFCP-EP POD.

Sx Modification response received at SGW-Service POD.

9, 10

Received Modify Bearer request from SGW-Service POD > S5 GTPC-EP POD with updated ULI.

Modify Bearer request is received at PGW.

11, 12

Received Modify Bearer response from PGW > S5 GTPC-EP POD.

Modify Bearer response received from S5 GTPC-EP POD > SGW-Service POD.

13

SGW-Service POD forwards Modify Bearer response to GTPC-EP POD ingress.

14, 15

Session updated at CDL. Transaction S-T1 is complete. GTPC-EP POD forwards Modify Bearer response to MME.