This section contains information to help you understand system problems reported through maintenance subsystem of Communication Manager. While pro-actively testing in the background, gathering and reporting vital information from several concurrent processes, Communication Manager maintenance can often notify you of problems before failures like variations in environments (temperature, voltages, fan speeds), and of irregularities in connections or services occur. While resolving the problem you must identify the location of the problem (IP telephone, network, PBX, and so on), by using alarms and the state information of devices along with any administration information that you gather. After the location is identified, repair the problem by correcting parameter provisioning, upgrading software or firmware, or replacing hardware.