Everytime a call has to be created, some parameters are required for
example to define the media mode or to select the originating address.
The CallParams property is used to provide the corresponding methods with
these information.
Methods that make use of the CallParams property are:
The CallParams property defines only a subset of all available call parameters.
If you need a feature, that is not provided by this property, you are
able to use methods that accept the LINECALLPARAMS
structure.
This propery indicates the originating address that is used when a call
is created. See the ThbTapiLine.Addresses
property for a list of available addresses for the line device. Legal
values range from 0 to ThbTapiLine.Addresses.Count - 1.
ThbTapiLine.CallParams.BearerMode
Type: DWORD (Cardinal)
This propery indicates the BearerMode to be used when a call is created.
If BearerMode is zero, the default value is LINEBEARERMODE_VOICE. See
the property ThbTapiLine.Caps.BearerModes
for available BearerModes for this line device. This member uses one of
the LINEBEARERMODE_ constants:
Constant
Meaning
LINEBEARERMODE_VOICE
This is a regular 3.1 kHz analog voice-grade bearer service. Bit integrity
is not assured. Voice can support fax and modem media types.
LINEBEARERMODE_SPEECH
This corresponds to G.711 speech transmission on the call. The network
can use processing techniques such as analog transmission, echo cancellation,
and compression/decompression. Bit integrity is not assured. Speech is
not intended to support fax and modem media types.
LINEBEARERMODE_MULTIUSE
The multiuse mode defined by ISDN.
LINEBEARERMODE_DATA
The unrestricted data transfer on the call. The data rate is specified
separately.
LINEBEARERMODE_ALTSPEECHDATA
The alternate transfer of speech or unrestricted data on the same call
(ISDN).
LINEBEARERMODE_NONCALLSIGNALING
This corresponds to a non-call-associated signaling connection from the
application to the service provider or switch (treated as a media stream
by TAPI).
LINEBEARERMODE_PASSTHROUGH
When a call is active in LINEBEARERMODE_PASSTHROUGH, the service provider
gives direct access to the attached hardware for control by the application.
This mode is used primarily by applications desiring temporary direct
control over asynchronous modems, accessed through the Win32 comm functions,
for the purpose of configuring or using special features not otherwise
supported by the service provider.
LINEBEARERMODE_RESTRICTEDDATA
Bearer service for digital data in which only the low-order seven bits
of each octet may contain user data (for example, for Switched 56kbit/s
service).
ThbTapiLine.CallParams.MediaMode
Type: DWORD (Cardinal)
This propery indicates the MediaMode which is used when a call is created.
If MediaMode is zero, the default value is LINEMEDIAMODE_INTERACTIVEVOICE.
See the property ThbTapiLine.Caps.MediaModes
for the available media modes for the selected line device. This member
uses one of the LINEMEDIAMODE_ constants:
Constant
Description
LINEMEDIAMODE_AUTOMATEDVOICE
Voice energy was detected on the call, and the voice is locally handled
by an automated application such as with an answering machine application.
When a service provider cannot distinguish between interactive and automated
voice on an incoming call, it will report the call as interactive voice.
LINEMEDIAMODE_DATAMODEM
A data modem session on the call.
LINEMEDIAMODE_ADSI
An ADSI (Analog Display Services Interface) session on the call. ADSI
enhances voice calls with alphanumeric information downloaded to the phone
and the use of soft buttons on the phone.
LINEMEDIAMODE_DIGITALDATA
A digital data stream of unspecified format.
LINEMEDIAMODE_G3FAX
A group 3 fax is being sent or received over the call.
LINEMEDIAMODE_G4FAX
A group 4 fax is being sent or received over the call.
LINEMEDIAMODE_INTERACTIVEVOICE
Voice energy was detected on the call, and the call is handled as an
interactive voice call with humans on both ends.
LINEMEDIAMODE_MIXED
A mixed session on the call. Mixed is one of the ISDN telematic services.
LINEMEDIAMODE_TDD
A TDD (Telephony Devices for the Deaf) session on the call.
LINEMEDIAMODE_TELETEX
A teletex session on the call. Teletex is one of the telematic services.
LINEMEDIAMODE_TELEX
A telex session on the call. Telex is one of the telematic services.
LINEMEDIAMODE_VIDEO
The media type of the call is video. (TAPI versions 2.1 and later)
LINEMEDIAMODE_VIDEOTEX
A videotex session on the call. Videotex is one the telematic services.
LINEMEDIAMODE_VOICEVIEW
The media type of the call is VoiceView. (TAPI versions 1.4 and later)
LINEMEDIAMODE_UNKNOWN
A media stream exists but its mode is not currently known and may become
known later. This would correspond to a call with an unclassified media
type. In typical analog telephony environments, an incoming call's media
type may be unknown until after the call has been answered and the media
stream has been filtered to make a determination.
If the unknown media-mode flag is set, other media flags can also be set.
This is used to signify that the media is unknown but that it is likely
to be one of the other selected media types.
ThbTapiLine.CallParams.BlockID
Type: Boolean
Set this property to True if the originator identity should be concealed
(block caller ID).
This property is only valid if the LINEADDRCAPFLAGS_BLOCKIDOVERRIDE bit
flags is set in the ThbTapiLine.Addresses[<any available>].Flags property.
If the LINEADDRCAPFLAGS_BLOCKIDDEFAULT bit flag is set, caller id blocking
is enabled by device default. See LINECALLPARAMS
for further features.
ThbTapiLine.CallParams.NoAnswerTimeout
Type: DWORD (Cardinal)
The number of seconds, after the completion of dialing, that the call
should be allowed to wait in the PROCEEDING or RINGBACK states, before
it is automatically abandoned by the service provider with a LINECALLSTATE_DISCONNECTED
and LINEDISCONNECTMODE_NOANSWER. A value of 0 indicates that the application
does not desire automatic call abandonment.