Question

Is it possible any scenario when sctp communication is up between mme and eNodeB but s1ap wil not be up ?
Is there need to send different alarm for s1ap failure and sctp communication failure as part of fault management . Please, suggest me required spec.

Answer 1

It might be possible that the information sent in S1-setup request was wrong and MME responded to eNodeB with S1-setup failure.
In this particular case, MME expects eNodeB will re-try S1-setup request with correct values.

Another scenario, when every thing was working perfectly over S1-C link and at sudden it stopped working. In such case, carrier grade product generates alarm and corrective actions are taken.