LINEDEVCAPS structure (tapi.h)
The LINEDEVCAPS structure describes the capabilities of a line device. The lineGetDevCaps function and the TSPI_lineGetDevCaps function return the LINEDEVCAPS structure.
Syntax
typedef struct linedevcaps_tag {
DWORD dwTotalSize;
DWORD dwNeededSize;
DWORD dwUsedSize;
DWORD dwProviderInfoSize;
DWORD dwProviderInfoOffset;
DWORD dwSwitchInfoSize;
DWORD dwSwitchInfoOffset;
DWORD dwPermanentLineID;
DWORD dwLineNameSize;
DWORD dwLineNameOffset;
DWORD dwStringFormat;
DWORD dwAddressModes;
DWORD dwNumAddresses;
DWORD dwBearerModes;
DWORD dwMaxRate;
DWORD dwMediaModes;
DWORD dwGenerateToneModes;
DWORD dwGenerateToneMaxNumFreq;
DWORD dwGenerateDigitModes;
DWORD dwMonitorToneMaxNumFreq;
DWORD dwMonitorToneMaxNumEntries;
DWORD dwMonitorDigitModes;
DWORD dwGatherDigitsMinTimeout;
DWORD dwGatherDigitsMaxTimeout;
DWORD dwMedCtlDigitMaxListSize;
DWORD dwMedCtlMediaMaxListSize;
DWORD dwMedCtlToneMaxListSize;
DWORD dwMedCtlCallStateMaxListSize;
DWORD dwDevCapFlags;
DWORD dwMaxNumActiveCalls;
DWORD dwAnswerMode;
DWORD dwRingModes;
DWORD dwLineStates;
DWORD dwUUIAcceptSize;
DWORD dwUUIAnswerSize;
DWORD dwUUIMakeCallSize;
DWORD dwUUIDropSize;
DWORD dwUUISendUserUserInfoSize;
DWORD dwUUICallInfoSize;
LINEDIALPARAMS MinDialParams;
LINEDIALPARAMS MaxDialParams;
LINEDIALPARAMS DefaultDialParams;
DWORD dwNumTerminals;
DWORD dwTerminalCapsSize;
DWORD dwTerminalCapsOffset;
DWORD dwTerminalTextEntrySize;
DWORD dwTerminalTextSize;
DWORD dwTerminalTextOffset;
DWORD dwDevSpecificSize;
DWORD dwDevSpecificOffset;
DWORD dwLineFeatures;
DWORD dwSettableDevStatus;
DWORD dwDeviceClassesSize;
DWORD dwDeviceClassesOffset;
GUID PermanentLineGuid;
DWORD dwAddressTypes;
GUID ProtocolGuid;
DWORD dwAvailableTracking;
} LINEDEVCAPS, *LPLINEDEVCAPS;
Members
dwTotalSize
Total size allocated to this data structure, in bytes.
dwNeededSize
Size needed for this data structure to hold all the returned information, in bytes.
dwUsedSize
Size of the portion of this data structure that contains useful information, in bytes.
dwProviderInfoSize
Size of the variably sized field containing service provider information, in bytes.
dwProviderInfoOffset
Offset from the beginning of the structure to the service provider information, in bytes.
The dwProviderInfoSize and dwProviderInfoOffset members are intended to provide information about the provider hardware and/or software, such as the vendor name and version numbers of hardware and software. This information can be useful when a user needs to call customer service with problems regarding the provider.
dwSwitchInfoSize
Size of the variably sized device field containing switch information, in bytes.
dwSwitchInfoOffset
Offset from the beginning of the structure to the switch information, in bytes.
The dwSwitchInfoSize and dwSwitchInfoOffset members are intended to provide information about the switch to which the line device is connected, such as the switch manufacturer, the model name, the software version, and so on. This information can be useful when a user needs to call customer service with problems regarding the switch.
dwPermanentLineID
Permanent identifier by which the line device is known in the system's configuration. It is a permanent name for the line device. This permanent name (as opposed to dwDeviceID) does not change as lines are added or removed from the system, and persists through operating system upgrades. It can therefore be used to link line-specific information in .ini files (or other files) in a way that is not affected by adding or removing other lines or by changing the operating system.
dwLineNameSize
Size of the variably sized device field containing a user configurable name for this line device, in bytes.
dwLineNameOffset
Offset from the beginning of this data structure to the name for this line device. This name can be configured by the user when configuring the line device's service provider, and is provided for the user's convenience. The size of the field is specified by dwLineNameSize.
dwStringFormat
String format used with this line device. This member uses one of the STRINGFORMAT_ Constants.
dwAddressModes
Mode by which the originating address is specified. This member uses the LINEADDRESSMODE_ Constants.
dwNumAddresses
Number of addresses associated with this line device. Individual addresses are referred to by address identifiers. Address identifiers range from zero to one less than the value indicated by dwNumAddresses.
dwBearerModes
Flag array that indicates the different bearer modes that the address is able to support. This member uses one or more of the LINEBEARERMODE_ Constants.
dwMaxRate
Maximum data rate for information exchange over the call, in bits per second.
dwMediaModes
Flag array that indicates the different media types the address is able to support. This member uses one or more of the LINEMEDIAMODE_ Constants.
dwGenerateToneModes
Tones that can be generated on this line. This member uses one or more of the LINETONEMODE_ Constants.
dwGenerateToneMaxNumFreq
Maximum number of frequencies that can be specified in describing a general tone using the LINEGENERATETONE data structure when generating a tone using lineGenerateTone. A value of 0 indicates that tone generation is not available.
dwGenerateDigitModes
Digit modes than can be generated on this line. This member uses one or more of the LINEDIGITMODE_ Constants.
dwMonitorToneMaxNumFreq
Maximum number of frequencies that can be specified in describing a general tone using the LINEMONITORTONE data structure when monitoring a general tone using lineMonitorTones. A value of 0 indicates that tone monitor is not available.
dwMonitorToneMaxNumEntries
Maximum number of entries that can be specified in a tone list to lineMonitorTones.
dwMonitorDigitModes
Digit modes than can be detected on this line. This member uses one or more of the LINEDIGITMODE_ Constants.
dwGatherDigitsMinTimeout
Minimum value that can be specified for both the first digit and inter-digit timeout values used by lineGatherDigits, in milliseconds. If both dwGatherDigitsMinTimeout and dwGatherDigitsMaxTimeout are zero, timeouts are not supported.
dwGatherDigitsMaxTimeout
Maximum value that can be specified for both the first digit and inter-digit timeout values used by lineGatherDigits, in milliseconds. If both dwGatherDigitsMinTimeout and dwGatherDigitsMaxTimeout are zero, timeouts are not supported.
dwMedCtlDigitMaxListSize
Maximum number of entries that can be specified in the digit list parameter of lineSetMediaControl.
dwMedCtlMediaMaxListSize
Maximum number of entries that can be specified in the media list parameter of lineSetMediaControl.
dwMedCtlToneMaxListSize
Maximum number of entries that can be specified in the tone list parameter of lineSetMediaControl.
dwMedCtlCallStateMaxListSize
Maximum number of entries that can be specified in the call state list parameter of lineSetMediaControl.
dwDevCapFlags
Boolean device capabilities. This member uses one or more of the LINEDEVCAPFLAGS_ Constants.
dwMaxNumActiveCalls
Maximum number of (minimum bandwidth) calls that can be active (connected) on the line at any one time. The actual number of active calls may be lower if higher bandwidth calls have been established on the line.
dwAnswerMode
Effect on the active call when answering another offering call on a line device. This member uses one of the LINEANSWERMODE_ Constants.
dwRingModes
Number of different ring modes that can be reported in the LINE_LINEDEVSTATE message with the ringing indication. Different ring modes range from one to dwRingModes. Zero indicates no ring.
dwLineStates
Different line status components for which the application may be notified in a LINE_LINEDEVSTATE message on this line. This member uses one or more of the LINEDEVSTATE_ Constants.
dwUUIAcceptSize
Maximum size of user-user information, including the null terminator, that can be sent during a call accept.
dwUUIAnswerSize
Maximum size of user-user information, including the null terminator, that can be sent during a call answer.
dwUUIMakeCallSize
Maximum size of user-user information, including the null terminator, that can be sent during a make call.
dwUUIDropSize
Maximum size of user-user information, including the null terminator, that can be sent during a call drop.
dwUUISendUserUserInfoSize
Maximum size of user-user information, including the null terminator, that can be sent separately any time during a call with lineSendUserUserInfo.
dwUUICallInfoSize
Maximum size of user-user information, including the null terminator, that can be received in the LINECALLINFO structure.
MinDialParams
Minimum value for the dial parameters that can be set for calls on this line, in milliseconds. Dialing parameters can be set to values in the range MinDialParams to MaxDialParams. The granularity of the actual settings is service provider-specific.
MaxDialParams
Maximum value for the dial parameters that can be set for calls on this line, in milliseconds. Dialing parameters can be set to values in the range MinDialParams to MaxDialParams. The granularity of the actual settings is service provider-specific.
DefaultDialParams
Default dial parameters used for calls on this line. These parameter values can be overridden on a per-call basis.
dwNumTerminals
Number of terminals that can be set for this line device, its addresses, or its calls. Individual terminals are referred to by terminal IDs and range from zero to one less than the value indicated by dwNumTerminals.
dwTerminalCapsSize
Size of the variably sized device field containing an array with entries of type LINETERMCAPS, in bytes.
dwTerminalCapsOffset
Offset from the beginning of this structure to the variably sized device field containing an array with entries of type LINETERMCAPS. This array is indexed by terminal IDs, in the range from zero to dwNumTerminals minus one. Each entry in the array specifies the terminal device capabilities of the corresponding terminal. The size of the field is specified by dwTerminalCapsSize.
dwTerminalTextEntrySize
Size of each of the terminal text descriptions, including the null terminator, pointed to by dwTerminalTextSize and dwTerminalTextOffset, in bytes.
dwTerminalTextSize
Size of the variably sized field containing descriptive text about each of the line's available terminals, including the null terminator, in bytes
dwTerminalTextOffset
Offset from the beginning of this structure to the descriptive text about each of the line's available terminals, in bytes. Each message is dwTerminalTextEntrySize bytes long. The string format of these textual descriptions is indicated by dwStringFormat in the line's device capabilities. The size of the field is specified by dwTerminalTextSize.
dwDevSpecificSize
Size of the variably sized device-specific field, in bytes. If the device-specific information is a pointer to a string, the size must include the null terminator.
dwDevSpecificOffset
Offset from the beginning of this structure to the device-specific field, in bytes. The size of the field is specified by dwDevSpecificSize.
dwLineFeatures
Features available for this line using the LINEFEATURE_ Constants. Invoking a supported feature requires the line to be in the proper state and the underlying line device to be opened in a compatible mode. A zero in a bit position indicates that the corresponding feature is never available. A one indicates that the corresponding feature may be available if the line is in the appropriate state for the operation to be meaningful. This member allows an application to discover which line features can be (and which can never be) supported by the device.
dwSettableDevStatus
LINEDEVSTATUSFLAGS values that can be modified using lineSetLineDevStatus.
dwDeviceClassesSize
Size of a string containing the device class identifiers supported on one or more addresses on this line, including the null terminator, in bytes.
dwDeviceClassesOffset
Offset from the beginning of this structure to a string containing the device class identifiers supported on one or more addresses on this line, in bytes. These strings are for use with lineGetID; they are separated by NULLs, and the last identifier in the list is followed by two NULLs. The size of the field is specified by dwDeviceClassesSize.
PermanentLineGuid
GUID permanently associated with the line device.
dwAddressTypes
Address type used for the call. This member of the structure is available only if the negotiated TAPI version is 3.0 or higher.
ProtocolGuid
Current TAPI protocol. This member of the structure is available only if the negotiated TAPI version is 3.0 or higher. The protocols are declared in tapi3.h.
dwAvailableTracking
Available tracking, as represented by a LINECALLHUBTRACKING.constant. This member of the structure is available only if the negotiated TAPI version is 3.0 or higher.
Remarks
Device-specific extensions should use the DevSpecific (dwDevSpecificSize and dwDevSpecificOffset) variably sized area of this data structure.
Older applications are compiled without new members in the LINEDEVCAPS structure, and using a SIZEOF LINEDEVCAPS smaller than the new size. The application passes in a dwAPIVersion parameter with the lineGetDevCaps function, which can be used for guidance by TAPI in handling this situation. If the application passes in a dwTotalSize member less than the size of the fixed portion of the structure as defined in the specified dwAPIVersion, LINEERR_STRUCTURETOOSMALL is returned. If sufficient memory has been allocated by the application, before calling TSPI_lineGetDevCaps, TAPI sets the dwNeededSize and dwUsedSize members to the fixed size of the structure as it existed in the specified API version.
New applications must be cognizant of the API version negotiated, and not examine the contents of members in the fixed portion beyond the original end of the fixed portion of the structure for the negotiated API version.
If the LINEBEARERMODE_DATA bit is set in the dwBearerModes member, the dwMaxRate member indicates the maximum rate of digital transmission on the bearer channel. The dwMaxRate member of the LINEDEVCAPS structure can contain valid values even if the dwBearerModes member of the LINEDEVCAPS structure is not set to LINEBEARERMODE_DATA.
If LINEBEARERMODE_DATA is not set in dwBearerModes, but the LINEBEARERMODE_VOICE value is set and the LINEMEDIAMODE_DATAMODEM value is set in the dwMediaModes member, the dwMaxRate member indicates the maximum SYNCHRONOUS (DCE) bit rate on the phone line for the attached modem or functional equivalent. For example, if the modem's fastest modulation speed is V.32bis at 14,400bps, dwMaxRate equals 14400. This is not the fastest DTE port rate (which would most likely be 38400, 57600, or 115200), but the fastest bit rate the modem supports on the phone line.
The application must be careful to check to see that LINEBEARERMODE_DATA is not set, to avoid misinterpreting the dwMaxRate member. It is likely to be 64000 or higher if LINEBEARERMODE_DATA is set.
It should also be noted that if the modem has not been specifically identified (for example, it is a "generic" modem), the figure indicated is a "best guess" based on examination of the modem.
The members dwSettableDevStatus through dwDeviceClassesOffset are available only to applications that open the line device with a TAPI version of 2.0 or later.
Requirements
| Requirement | Value |
|---|---|
| Header | tapi.h |