In this procedure, the gNB-CU will initiate the cell change to gNB-DU. At first, GNB_DU and CU will set up a connection between them, and after that, the gNB-CU initiates the Cell Change procedure by sending a GNB-CU CONFIGURATION UPDATE message to GNB-DU with “cells to be activated list” (SIB2). In response, GNB-DU will send an acknowledgment to GNB_CU.

This test case is as per 3GPP Spec: TS 38.401, TS 38.473   Version: 16