Collision Resolver Discard Handling Call Flow
This section describes the Collision Resolver Discard Handling call flow.

Step |
Description |
---|---|
1 |
Initial Attach procedure is completed. The PDN1(ebi 5), PDN2(ebi 6), and PDN3(ebi 7) is established. The PGW sends the Create Bearer Request for PDN1 to the S5-GTP-EP. |
2 |
The PFCP-EP sends the Create Bearer Request 1 for PDN1 to the cnSGW. |
3 |
The cnSGW sends the Sx Modify Request 1 for PDN1 to the PFCP-EP. |
4, 5 |
The PGW sends the Delete Bearer Request (ebi5) for PDN1 to the cnSGW. |
6 |
Collision detected for PDN1. The Create Bearer Request is discarded as network initiated PDN deletion request is triggered. The cnSGW sends a response message with the cause as EGTP_CAUSE_SN_MALFORMED_MSG to the endpoint pod. The cnSGW sends Create Bearer Response (discard 1) for PDN1 to the S5-GTP-EP. |
7 |
The cnSGW sends the Sx Modify Request 1 (DBR1) for PDN1 to the PFPC-EP. |
8 |
The cnSGW receives the Sx Modify Response 1 (DBR1) for PDN1 from the PFPC-EP. |
9 |
The cnSGW sends the Delete Bearer Request 1 to the S11-GTP-EP. |
10 |
The S11-GTP-EP sends the Delete Bearer Request 1 to the MME. |
11 |
The MME sends the Delete Bearer Response 1 to the S11-GTP-EP. |
12 |
The S11-GTP-EP sends the Delete Bearer Response 1 to the cnSGW. |
13 |
The cnSGW sends the Sx Delete Request for PDN1 to the PFCP-EP. |
14 |
The PFPC-EP sends the Sx Delete Response for PDN1 to the cnSGW. |
15 |
The cnSGW sends the Delete Bearer Response 1 for PDN1 to the PGW. |
16 |
The S5-GTP-EP sends the Delete Bearer Response for PDN1 to the PGW. |