No User Connect Timer Support

  1. MME sends Release Access Bearer request to SGW-C to release downlink remote TEIDs of all the bearers for that UE.

  2. On arrival of Release Access Bearer request, SGW-C informs the same to SGW-U by updating FAR with Apply Action as BUFFER in Sx Modification Request for all the PDNs.

  3. SGW-U send Sx Modification response after applying Buffering in SGW-U for corresponding PDN.

  4. SGW-C sends Release Access Bearer response to MME.

  5. First Downlink data arriving in SGW-U triggers Sx Report Request (with Report Type as Downlink Data Report) towards SGW-C.

  6. On arrival of Sx Report Request message, the SGW-C initiates Downlink Data Notification request message towards MME.

  7. SGW-C sends Sx Report Response message towards SGW-U.

  8. Downlink Data Notification Acknowledgment is received from MME.SGW-C starts no-user-connect timer.

  9. If the Modify Bearer request with eNodeB TEID information is not received and no-user-connect timer expires, SGW-C sends Downlink Data Notification again.

  10. Downlink Data Notification Acknowledgment is received from MME. SGW-C initiates the no-user-connect timer again.

  11. SGW-C initiates Sx Session Modification request towards SGW-U with DROBU flag set in the message. On receiving this flag SGW-U drops the buffered data. New data will be buffered, and the subsequent first packet initiates a Sx Report message for initiating Downlink Data Notification message.

  12. SGW-U sends Sx Modification Response.