DDN Throttling Call Flow

This section describes DDN Throttling call flow.

DDN Throttling Call Flow
DDN Throttling Call Flow Description

Step

Description

1

Received DDN with throttling parameters when UE is in IDLE state.

MME sends the DDN ACK to the S11-GTP-EP.

2

SGW-UP sends the Sx Report Request with report type as DLDR with corresponding PDR ID to PFCP-EP.

3

PFCP-EP triggers a new P-T1 transaction and routes the Sx Report Request to available service pod.

PFCP-EP sends the Sx Session Report Request to the SGW-service pod.

4

Started a new S-T2 transaction.

Get peer information to check if DDN Throttle is active for this peer.

Check if priority of this bearer is more than the configured ARP watermark

SGW-service pod sends the Sx session Report Response to the PFCP-EP.

5

S-T2 transaction started in step four is completed.

P-T1 transaction started in step threee is completed.

When a bearer found at CP for this PDR ID, the PFCP-EP sends success response to the SGW-UP.

6

A new S-T3 transaction is started for the UE for which DDN is not triggered.

Apply DDN algorithm to check if the DDN must be throttled.

If DDN throttled, SGW-service pod sends the Sx Modification Request with Apply Action as BUFFER towards PFCP-EP.

7, 8

P-T4 transaction is completed.

PFCP-EP sends the Sx Session Modification Request to the SGW-UP and receives the Sx Session Modification Response from the SGW-UP.

9

P-T1 transaction started in step five is completed.

PFCP-EP sends Sx Modification Response to the SGW-service pod.

10

S-T3 transaction started in step six is completed.

SGW-service pod updates the session to CDL.