When does MME triggers detach procedure for an UE?

Question

I want to know the different scenarios of MME initiated detach procedure, please share the detail?

Answer 1

I few few of the cases when MME can initiate detach procedure for an UE.
1- From OAM, it is possible to trigger detach procedure for an UE
2- Subscription has been expired at the HSS and it initiates Delete subscriber data procedure. As result of this procedure, MME initiate detach procedure.
3- Congestion is detected at the serving MME.
4- UE did combined attach at MME but due to some issue non-EPS services can't be provided. In this case, MME initiates detach procedure with detach type "IMSI detach".

These are the few cases when MME initiates detach procedure.

Comments

Thanks vimal, I need a clarification, if authentication of ue fails whether mme wil initiate detach procedure towards ue or not ??

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I think the case you are talking is related to "implicit detach" at MME. After sending authentication reject, MME and UE both do implicit detach. I am still not sure 100 percent.