How to improve the "L.E-RAB.FailEst.SecurModeFail"?

4G LTE
1

How to improve the “L.E-RAB.FailEst.SecurModeFail”?
Vendor Huawei

2

Is it EPC related issue?

3

No, it’s not.

4

Issue is due EPC or UE with same TMSI or capability failure or eNodeB license expiration.
Check also uumsgsimulsendswitch and seccmpwaitingtimer.

5

UuMsgSimulSendSwitch ON

UuMessageWaitingTimer Then we need to check this para?

Indicates the timer for the eNodeB to wait for a Security Mode Complete message. If the UuMsgSimulSendSwitch is set to ON, this parameter does not take effect and the timer for the eNodeB to wait for a Security Mode Complete message is specified by the UuMessageWaitingTimer parameter.

6

One of the possible cause for Erab fail is Security mode command Failure, once the ENODEB gets s1 initial context setup request then it sends security mode command and RRC connection reconfiguration command to the UE, the UE can respond back with the security mode fail. sometimes there are UEs that do not support security mode command and RRC reconfiguration to be bundled together. so if you have this issue a lot in your network then what you can do is you can ensure that you transmit the security mode command and RRC REconfiguration separately and do not bundle them together.
UuMsgSimulSendSwitch
but mostly this issue is related to simcard especially usim and its counters.
in most cases, after informing the customer to change the simcard, issue is recovered.