 be used, for example, to evaluate the network performance in the slicing scenario. To this end, 3GPP provided specifications for KPIs specific to NSSIs and NSIs. One difference specific to performance measurements for slicing is that the performance data are received from multiple NFs, and the NSI performance data are computed based on the performance data received from multiple NSIs and possibly individual NFs. 6.5.6 Management of Split NG-RAN 6.5.6.1 Background In 5G, 3GPP defined not only the monolithic NG-RAN architecture, but also a number of split gNB architectures. In these architectures, a gNB can be split into a centralized node, referred to as gNB-CU, and multiple distributed nodes, referred to as gNB-DUs. Addition- ally, a gNB-CU may be further split into a control-plane node, referred to as gNB-CU-CP, and possibly one or multiple user-plane nodes, referred to as gNB-CU-UP. These architec- tures are described in detail in Sections 4.2 and 4.4. 6.5.6.2 Information Object Classes The NG-RAN NRM was designed to enable "separate" provisioning of gNB-CU, gNB-DU, gNB-CU-CP, and gNB-CU-UP. Figure 6.5.4 (3GPP TS 28.541) shows the "containment" rela- tions between the IOCs in the gNB NRM. The gNB NRM is applicable to all deployment scenarios including monolithic gNB. The model fragments are for the representation of both gNB and en-gNB (see Section 4.3). The object classes used in NR modeling shown in Figure 6.5.4 are derived from the Man- aged Function class. There are object classes defined for gNB and en-gNB or their compo- nents, as explained in Table 6.5.2. Furthermore, the following IOCs are defined in association with certain RAN compo- nents to serve some special needs. For example, the gNB-CU needs some information from the particular cells served by all connected DUs, as shown in Table 6.5.3. 6.5 Operations, Administration, and Management aInformationObjectClassx ManagedElement <<names>> <<names>> <<names>> <<names>> aInformationObjectClassx aoInformationObjectClassx aInformationObjectClassx xProxyCl