Why UE sends UL information transfer emm status message and how network handles this?

4G LTE
,
1

Hi Experts,
When Network sends LTE RRC connection release UE sends ul information transfer emm status message.
Why UE sends this and how network handles this?

2

I think UL information transfer or DL information transfer used in RRC connected mode .
Purpose is to transfer NAS or non 3gpp dedicated information.
After RRC connection release, UE move to RRC idle.

3

We are using simulator for network.
The below is the call flow:
Lteattach -> pdn est -> rrc conn release by network -> serv request -> auth/sec procedure -> drb reest -> serv accept -> rrc conn release.

It was for this 2nd release ulinfotransfer emm status from UE observed.
I removed DRB reest part.
Now UE sending serv request again.