Enabling Message-level Back-off Timer

Use the following sample configuration to enable the back-off timer at the GTP-C and N1 message levels.

config 
   profile access access_profile_name 
      gtpc message-handling create-session-response condition ip-exhaust action backoff cause cause_code_value 
      n1 message-handling pdu-session-release condition n4-pathfail action backoff cause cause_code_value 
      n1 message-handling pdu-session-establishment condition ip-exhaust action backoff cause cause_code_value 
      end 

NOTES:

  • gtpc message-handling create-session-response condition ip-exhaust action backoff cause cause_code_value : Use this command to enable back-off timer at the GTP-C interface level for the Create Session Response (CSR) message. That is, the CSR message includes the Back-off Timer IE and its cause code during the exhaustion of IP address.

  • n1 message-handling pdu-session-release condition n4-pathfail action backoff cause cause_code_value : Use this command to enable back-off timer at the N1 interface level for the PDU Session Release message. That is, the PDU Session Release message includes the Back-off Timer IE and its cause code when the N4 path failure occurs.

  • n1 message-handling pdu-session-establishment condition ip-exhaust action backoff cause cause_code_value : Use this command to enable back-off timer at the N1 interface level for the PDU Session Establishment message. That is, the PDU Session Establishment message includes the Back-off Timer IE and its cause code during the exhaustion of IP address.

The following is an example configuration used during the 4G attach and the exhaustion of IP addresses.

config 
   profile access access1 
      gtpc message-handling create-session-response condition ip-exhaust action backoff cause 73 
      end 

In this scenario, the attach fails and the CSR is sent with Back-off Timer IE and cause 73.

The following is an example configuration used during the 5G attach and the exhaustion of IP addresses.

config 
   profile access access1 
      n1 message-handling pdu-establishment condition ip-exhaust action backoff cause 26 
      end 

In this scenario, the attach fails and the PDU Session Establishment is sent with Back-off Timer and cause code value set to 26.

The following is an example configuration used during the 5G attach and the N4 path failure scenario.

config 
   profile access access1 
      n1 message-handling pdu-session-release condition n4-pathfail action backoff cause 26 
      end 

In this scenario, clear subscriber is triggered internally and PDU Session Release command is sent with Back-off Timer IE and cause 26.