Involves :

a. Extracting of cell and UE configuration received from source DU at CU in UE context modification response(in response to GNB-DU configuration query)

b. Filling of UE context setup request with the extracted configurations and sending to target DU.

c. UE context and RB creation at RLC and MAC in target DU

d. RACH resource request and response to allocate dedicated preamble for UE in handover

d. UE context setup response from target DU to CU