Performance Monitor now includes a set of counters for monitoring telephone equipment attached to or associated with a computer, including telephones, telephone lines, and modems. Windows NT 4.0 Workstation and Server include a telephone device application program interface (TAPI) that allows Windows NT applications to communicate with telephone devices without regard to the characteristics of the device. The new Performance Monitor counters let you monitor devices that use TAPI.
The telephony counters are listed in Performance Monitor under the Telephony object. Counters include numbers of telephone devices, telephone lines, active lines, incoming and outgoing calls, and the number of applications using the telephone device.