The Network Control Board (NCB) module is the hardware platform for the Subnetwork Manager (SNM) software package, which you access using the Ethernet connector on the front of the NCB module or from the EIA/TIA-232 interface on the CIM module. The NCB supervises, administers, and monitors the ONS 15252. In addition to controlling all of the ONS 15252 system CLIP modules, the NCB module collects information about system status, alarms, parameters, and actions on the internal data bus. You can also store performance monitoring data on the NCB and upload the data to external media.