Hello friends
I'd like to share with you how to solve S1 Interface Fault Alarm ?
1- Alarm's Description
2- Causes of appearing Alarm
3- Procedures of Troubleshooting
An S1 interface alarm appears when
1) The Stream Control Transmission Protocol (SCTP) link malfunctions.
2) The S1 link cannot be set up because the configuration data of the S1 Application Protocol (S1AP) layer is incorrect
3) The S1 link is blocked
4) The MME is abnormal
And the Causes of appearing Alarm as the Following
1.The S1 interface is incorrectly configured
2. The S1 interface of the local eNodeB is blocked
3. The eNodeB configuration is incorrectly configured
4. The status of the SCTP link is abnormal.
5. The SCTP link is not configured.
6.The SCTP link is blocked.
7.The number of base stations connected to the MME reaches the upper limit allowed by the MME (Mobility Management Entity )
8. The MME code (MMEC) is the same as an existing one and The MME code (MMEC) conflicts with the MMEC on another S1 link
And the Procedures of Troubleshooting as the Following
Step ①: Check the configuration of the S1 interface.
ü Run the Command DSP S1INTERFACE to check the SCTP link number corresponding to the S1 interface is correct..
Step ②: Check for the SCTP link used by the S1 interface.
ü Run the Command DSP S1INTERFACE to check the SCTP link number for the S1 interface.
ü Run the Command LST SCTPLNK/LST SCTPLNK6 to check the SCTP link used by the S1 interface is configured.
ü Run the Command ADD SCTPLNK/ADD SCTPLNK6 to add an SCTP link to be used by the S1 interface.
Step ③: Check the status of the SCTP
ü Run the Command LST SCTPLNK/LST SCTPLNK6 to check whether the SCTP link used by the S1 interface is blocked.
ü Run the Command UBL SCTPLNK/UBL SCTPLNK6 to unblock the SCTP link.
Step ④: Check the configuration of the base station.
ü Run the Command LST ENODEB to check the configured identity of the base station is consistent with the configuration plan.
ü Run the Command MOD ENODEB to change the identity of the base station if it is inconsistent with the configuration plan
Step ⑤: Check the cause of S1 interface setup failure.
ü Run the Command DSP S1INTERFACE to check the S1 interface fails to be set up because the MMEC is the same as an existing one.
Step ⑦: Check the number of base stations connected to the MME.
ü Contact with 2nd line to check the number of base stations connected to the MME has reached the upper limit.
Best Regards
Walid Nawar - PDAC - MVE
