DDN Delay Call Flow

This section describes DDN Delay call flow.

DDN Delay Call Flow
DDN Delay Call Flow Description

Step

Description

1

Received downlink data when UE is in IDLE state.

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

2

Started a new P-T1 transaction.

PFCP-EP pod:

  • Checks the available service pod.

  • Sends the Sx Session Report to the the SGW-service pod.

3

A new transaction S-T2 is stared.

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

4

The S-T2, P-T1 transactions are completed.

PFCP-EP sends the Sx Session Report Response to the SGW-UP.

5

A new transaction S-T3 is started when DDN is not triggered for this UE.

Sgw-service pod gets the peer information to check if the peer configured with the DDN delay value.

DDN delay timer is triggered, if DDN delay configured.

S-T3 transaction is completed.

SGW-service pod sends the CDL update.

6, 7

A new S-T4 transaction started.

SGW-service pod sends the DDN to the S11-GTP-EP.

A new E-T5 transaction is started.

S11-GTP-EP forwards the DDN to the MME.

8, 9

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

Transaction E-T5 started in step seven is completed.

S11-GTP-EP forwards the DDN ACK success towards the SGW-service pod.

10

Transaction S-T4 started in step six is completed.

SGW-service pod updates session information to CDL.