Transferring Calls; Conferencing - Toshiba Strata DK40 Installation & Maintenance Manual

Transferring Calls

Transferring Calls
TAPI provides two mechanisms for call transfer: blind transfer or consultation transfer.
In blind transfer, an existing call is transferred to a specified destination address in one
phase using lineBlind transfer.
In a consultation transfer, the existing call is first prepared for transfer to another
address using lineSetup Transfer. This places the existing call on consultation hold,
and identifies the call as the target for the next transfer-completion request. This
command also allocates a consultation call that can be used to establish the
consultation call with the party to which the call will be transferred.
The application can dial the extension of the destination party on the consultation call using
lineDial, or it can drop and deallocate the consultation call and instead activate an existing
held call (lineUnhold). Finally, the application completes the transfer of the call on transfer
hold to the destination party by using lineComplete Transfer. At this point, both call
appearances revert to the IDLE state.
lineBlind Transfer
This function performs a single-step transfer of the specified call to the specified destination
address. The IpszDestAddress is interpreted in the same manner as lineMakeCall function.
lineSetup Transfer
This function initiates the transfer of the specified call. It establishes a consultation call,
IphdConsultCall, on which the party can be dialled that can become the destination of the
transfer. The original call transitions to the ONHOLDPENDTRANSFER state.
lineComplete Transfer
This function completes the transfer of the specified call to the party, or enter a three-way
conference, connected in the consultation call.

Conferencing

A conference call must begin as regular two-party call. Additional parties can be added, one
at a time. Calling lineSetupConference prepares a given call for the addition of another party,
and this action establishes the conference call. This operation takes the original two-party
call as input, allocates a conference call, connects the original call to the conference, and
allocates a consultation call whose handle is returned to the application.
The application can then use lineDial on the consultation call to establish a connection to the
next party to be added. lineDrop can be used to abandon this call attempt. The third party is
added with the function lineAddToConference, which specifies both the conference call and
the consultation call.
To add additional parties to an existing conference call, the application uses
linePrepareAddToConference. When calling this function, the application supplies the
handle of an existing conference call. The function allocates a consultation call that can later
be added to the conference call and returns a consultation call handle to the application. This
conference call is then placed on conference hold.
Strata DK40 I&M Manual Spring 1999
Refer to the Strata DK40 Programming Manual or DK Library CD-Rom for more details.
Computer Telephony Integration
8-23