/mcpUnified Communications Manager server phones a teleworker at home to establish a persistent connection that remains active all day, until the application drops the call. At least one remote destination must be configured and active on the CTI remote device in order to create a persistent call. One persistent call for each remote device is allowed at a time. No feature invocations, such as park, hold, conference, and transfer, are allowed on persistent calls. Once a persistent call is created it remains connected until application drops the call or the maximum call duration timer expires. A persistent call is also disconnected when a remote destination drops the call or is no longer active. Persistent calls cannot be dropped if an active call to the remote device exists. Therefore, if there is an active call, the persistent call will be dropped as soon as that call is finished. A Persistent Connection Call differs from a typical call in that no media events are generated for the persistent call. An application may not always receive notification about a persistent call that was accepted (LNECALLSTATE_ACCEPTED). This notification may depend on the type of trunks and gateways used in a specific telephone network. The Persistent Call feature enhances some TAPI APIs and introduces new APIs and error codes. This feature is backward compatible and existing applications are not affected. Note Create a Persistent Call The TAPI lineMakeCall function is used to create persistent call.. The relevant data is provided in LINECALLPARAMS structure pointed to by the lpLineCallParams parameter. Cisco TSP ignores all other lineMakeCall parameter for a persistent call. For a persistent call, the LINECALLPARAMS contains the following data: • DevSpecific part refering to Cisco_CallParamsDevSpecific structure where DevSpecificFlags is set to Cisco_CALLPARAMS_DEVSPECIFICFLAGS_PERSISTENT CALL (0x00000002) • CallingPartyID set to a directory number that appears as a remote destination CallerID directory number • DisplayableAddress set to a name that appears as the remote destination CallerIDName. Drop a Persistent Call Use the standard TAPI lineDrop function to drop or disconnect persistent call. The hCall parameter should specify the persistent call handle (HCALL) returned by lineMakeCall when the persistent call was created. Persistent Call State Change When the persistent call status changes, an application receives a standard TAPI LINE_CALLSTATE message. For a persistent call, the new call state in the dwParamas1 field will be constructed as follows: • The low-order 24 bits are set to one of the LINECALLSTATE_constants as they are for a regular call. • The high-order 8 bits is set to 0x20. A corresponding bitmask is defined in CiscoLineDevspecificMsg header file as CLDSMET_PERSISTENT_CALL_STATE (0x200000000). Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 44 Features Supported by TSP Persistent Connection