Performance Counters

Performance counters reflect the performance data of Cisco CallManager. A counter is a variable whose name is stored in the Registry. Each counter is related to a specific area of system functionality. Examples include busy time of the processor, memory usage, and the number of bytes received over a network connection. Each counter is uniquely identified through its name and its path or location. In the same way that a file path includes drives, directories, subdirectories, and filenames, a counter path consists of four elements: the machine, the object (for example, processor or IP), the object instance (type of counter value; for example, interrupt), and the counter name (special counter itself).

Performance counters are ideal for administrators for system maintenance, analysis, and troubleshooting tasks:

• An administrator needs to reset a voice gateway. With performance counters, it is possible to watch the system until the last call is disconnected and then reset the gateway.
• A user reports that using Cisco CallManager Extension Mobility to log in to the phone takes a very long time. In analyzing the statistics produced with performance counter data, the administrator discovers high processor usage and memory allocation due to problems with processes on the system.
• An administrator is dealing with a slow system. The system engineer has to decide whether system expansion is necessary or whether the current extensive system usage is only a one-time situation. To find out, the administrator should watch the system for a while.

Note

All performance counter values are based on system events and utilization information provided by the Microsoft Windows 2000 platform.

Performance Analysis

Microsoft Performance Monitor and Cisco Real-Time Monitoring Tool (RTMT) use Windows 2000 performance counters to monitor the system. Microsoft Performance Monitor, shown in Figure 31-1, reports both general and specific information in real time, whereas RTMT, shown in Figure 31-2, monitors focused Cisco CallManager performance by periodically polling Windows 2000 performance counter values.

Figure 31-1. Microsoft Windows 2000 Performance Monitor

Figure 31-2. Cisco Real-Time Monitoring Tool

RTMT provides optimized monitoring of performance objects and devices related just to the Cisco CallManager. The device information includes device registration status, IP address, description, and model type. RTMT provides clusterwide information that is stored in eight tables. The tables include IP phones, gateway devices, media, H.323 devices, Session Initiation Protocol (SIP) trunks, hunt lists, computer telephony integration (CTI), and voice messaging. RTMT also displays object and counter information that is kept by each Cisco CallManager node in the cluster. RTMT directly monitors the performance objects and counters.