/mcpMWI also includes two CCiscoLineDevSpecific subclasses are added to enhance the MWI functionality. Similar to the existing setMessageWaiting operation, one MWI operation sets the summary information for the controlled line, while the another MWI operation sets the message summary information on any line that is reachable by the controlled line, as defined by the configured calling search space of the controlled line. Interface Changes See Message Summary, on page 350 and Message Summary Dirn, on page 352. Message Sequences There are no message sequences for this feature. Backward Compatibility This feature is backward compatible. Monitoring Call Park Directory Numbers Cisco TSP supports monitoring calls on lines that represent Unified Communications Manager Administration Call Park Directory Numbers (Call Park DNs). Cisco TSP uses a device-specific extension in the LINEDEVCAPS structure that enables TAPI applications to differentiate Call Park DN lines from other lines. If an application opens a Call Park DN line, all calls that are parked to the Call Park DN are reported to the application. The application cannot perform any call-control functions on any of the calls at a Call Park DN. In order to open Call Park DN lines, the Monitor Call Park DNs check box in theUnified Communications Manager Administration for the TSP user must be checked. Otherwise, the application will not see any of the Call Park DN lines upon initialization. Multiple Calls Per Line Appearance The following topics describe the conditions of Line Appearance. Maximum Number of Calls The maximum number of calls per Line Appearance remains database configurable, which means that the Cisco TSP supports more than two calls per line on Multiple Call Display (MCD) devices. An MCD device comprises a device that can display more than two call instances per DN at any given time. For non-MCD devices, the Cisco TSP supports a maximum of two calls per line. The absolute maximum number of calls per line appearance equals 200. Busy Trigger In Cisco Unified CM, a setting, busy trigger, indicates the limit on the number of calls per line appearance before the Cisco Unified CM will reject an incoming call. Be aware that the busy trigger setting is database configurable, per line appearance, per cluster. The busy trigger setting replaces the old call waiting flag per DN. You cannot modify the busy trigger setting using the CiscoTSP. Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 78 Features Supported by TSP Monitoring Call Park Directory Numbers