• UCC cnSGW-C - Release Change Reference
  • About cnSGW
    • 5G Architecture
    • cnSGW-C Overview
    • Deploying and Configuring cnSGW-C through Operations Center
    • Smart Licensing Support
    • cnSGW-C Rolling Software Update
    • Pods and Services Reference
    • 3GPP RAN/NAS Cause Codes Support
    • Access Bearer Release Support
    • APN Profile Support
    • Change Notification Request Handling
    • Clear Subscriber Request
    • Context Replacement Support
    • Dedicated Bearer Support
    • Delete Bearer and Delete Session Request
    • Downlink Data Notification
      • Feature Summary and Revision History
      • Feature Description
      • DDN Message Handling
        • Feature Description
        • How it Works
          • Call Flows
            • Downlink Data Notification Success Call Flow
            • Downlink Data Notification Failure Call Flow
            • No User Connect Retry Timer Call Flow
        • Feature Configuration
      • Control Messages Triggered DDN Support
      • DDN Advance Features
    • DSCP Marking Support
    • Dynamic Routing by Using BGP
    • Emergency Call Support
    • Extended and Non-Standard QCI Values Support and Validation
    • eMPS/WPS Support
    • Failure and Error Handling Support
    • GTPC and Sx Path Management
    • GTPU Error Indication
    • GTPU Path Failure
    • GTPv2 and Sx Messages Retransmission and Timeout Handling
    • GTPv2 Load/Overload Support
    • GTPv2 Message Validation
    • IDFT Support
    • Idle Session Timeout Settings
    • Initial Attach Support
    • Inter System RAT Handover
    • Intra-MME and Inter-MME Handover Procedures
    • MCC/MNC Configuration in the SGW Service
    • Message Interactions Support
    • Modify and Delete Bearer Command Support
    • Modify Bearer Request Support
    • Monitor Subscriber and Protocol Support
    • Multiple PDN Attach or Detach Procedures
    • Performance Optimization Support
    • Presence Reporting Area
    • Redundancy Support
    • Service Configuration Enhancements
    • SGW Charging Support
    • SGW Relocation Support
    • Sx Load/Overload Control Handling
    • Stale Session Handling and Clearing
    • Update Bearer Request and Response
    • UPF Selection Support
    • VoLTE Call Prioritization
    • cnSGW-C Troubleshooting
  • Sample cnSGW Configuration
  • Statistics and KPI Reference

Downlink Data Notification Success Call Flow

This section describes the Downlink Data Notification Success call flow.

Downlink Data Notification Success Procedure Call Flow
Downlink Data Notification Success Procedure Call Flow Description

Step

Description

1

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

2

After receiving the Session Report Request, the PFCP-EP performs the following:
  • Starts a new P-T1 transaction.

  • Checks for the interface type. If its Sxa interface, it finds the available SGW-service pod and routes the request accordingly.

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

3

Upon reception of the Sx Session Report Request, SGW-service pod:

  • Creates a new S-T2 transaction.

  • Based on the message type received, updates the state processing not required for this message.

  • Handles the non-state processing transaction. (High priority is given to handle such messages).

  • Searches for the bearer based on PDR ID. If the bearer isn’t found, the SGW-service pod fills the cause as request rejected in the Session Report Response.

  • If the received report type in the request isn’t valid/supported, SGW-service pod fills the cause as request rejected and sends the Sx Session Report Response.

4

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

5

P-T1 transaction which is started at step one is completed.

At SGW-service pod:

  • S-T2 transaction which is started at step two is completed.

  • If the Sx Session Report Response is success, a new internal transaction S-T3 is started with the same buffer as of the Session Report Request.

  • A DDN procedure for DLDR report type is initiated.

  • Bearer information is extracted from the received PDR ID.

  • Bearer context is updated with buffer-data_ind.

  • Initiated the DDN with EBI of bearers, which has downlink data, and minimum ARP among these bearers.

  • Sends the DDN to the S11-GTP-EP pod.

6

After receiving the DDN, S11-GTP-EP:

  • Creates a new E-T4 transaction.

  • Sends the DDN to the MME.

7

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

8

The transaction S-T3 which is started after step four is complete.

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

9

SGW-service pod updates the CDL.

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