Is there any significance of "SN status transfer" message exchange between eNodeBs while doing X2 handover procedure ?

Question

What is exactly done during X2 reset procedure in LTE? Spec talks about deleting peer eNB context.
What eNB context gets deleted during "X2 Reset" procedure? Also what is "application level configuration" as mentioned in X2 spec 36.423?

Answer 1

The source eNB sends the SN STATUS TRANSFER message to the target eNB to convey the uplink PDCP SN receiver status and the downlink PDCP SN transmitter status of E-RABs for which PDCP status preservation applies (i.e. for RLC AM) during X2 handover.

Comments

During HO execution phase...Source enodeB sends Handover command (RRC Connection Reconfiguration Command)to UE which instructs UE to detach from source enodeB. After that Source enodeB sends "SN status Transfer message" (contains DL count and UL count). UL count is count of first UL packet that is to be received by Target enodeB from UE. DL count is count of first DL packet that is to be received by UE from Target enodeB. I hope it will clear your doubt.