High number of cause code 34c s1sctp out of service on eNodeB

I’m getting high number of cause code 34c s1sctp out of service on eNB.

Is this issue with S1 link between eNB and MME?
Or eNB and SGW?

Samsung system.

If it is SCTP issue, mostly it will be on S1-C (Toward MME).

Yes it’s SCTP issue and during same time eNB is flapping its availability getting impacted.

SCTP is signalling protocol so should be between eNB and MME.

For SGW, eNB uses gtp-u prrotocol.

I haven’t seen any SCTP message transfers between eNB and SGW.

Need to check connectivity between eNB and MME first.

My question is since S1 link is having logical interface between MME (S1-C) and SGW (s1-U) so in case eNB is having high s1sctp cause code than does it indicates issue between eNB and MME only or there is a issue with S1 link as a whole.

Is it due to single eNB or multiple eNB?

Please check this cc 34c.

As per that need to drill down further.

Multiple eNB are impacted.

All of them from same cluster or region?

Also, check if it’s from same cluster then any new MME defined in pool recently or not.

If not then see S1 link status of all MME randomly for few eNB.

All sites are in same cluster and S1 link status is ok for all the eNB.

One thing is comman that all these sites connected to same BH aggregation node.

Then you need to check with BH team.