2.2.4.1.3.18 GenerateDigits

The GenerateDigits packet is transmitted from a TAPI client to a TAPI server in a remote procedure call. Sending this packet initiates the generation of the specified digits on the specified call as inband tones by using the specified signaling mode. Invoking this function while digit or tone generation is in progress aborts the current digit or tone generation. Passing a NULL value for lpszDigits generates no new digits.


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Req_Func

Reserved1

hCall

dwDigitMode

lpszDigits

dwDuration

dwEndToEndID

Reserved2

Reserved3

Reserved4

Reserved5

Reserved6

Reserved7

Reserved8

Reserved9

VarData (variable)

...

Req_Func (4 bytes): The identifier of the function that will be invoked on the remote server. This value MUST be set to 19.

Note At any time, only one inband generation request (tone generation or digit generation) can be in progress per call.

Return Values

On completion of ClientRequest, this field contains the result of the encapsulated telephony request. A value of 0 indicates success and a LINEERR_Constants value indicates failure. The remote server MUST complete this call synchronously.

MUST return zero if the function succeeds or an error number if an error occurs. Common return values are as follows:

Name

Value

LINEERR_INVALCALLHANDLE

0x80000018

LINEERR_NOMEM

0x80000044

LINEERR_INVALCALLSTATE

0x8000001C

LINEERR_OPERATIONUNAVAIL

0x80000049

LINEERR_INVALDIGITMODE

0x80000027

LINEERR_OPERATIONFAILED

0x80000048

LINEERR_RESOURCEUNAVAIL

0x8000004B

Reserved1 (4 bytes): An unsigned 32-bit integer. MUST be set to zero when sent and MUST be ignored on receipt.

hCall (4 bytes): An HCALL. The handle to the call. One way of obtaining a valid hCall is by sending the MakeCall packet.  The application MUST be an owner of the call. The call state of hCall can be any state. TAPI does not impose any call state requirements; however, some Tapi Service Providers can require that the hCall be is the LINECALLSTATE_CONNECTED state.

dwDigitMode (4 bytes): An unsigned 32-bit integer. The format to be used for signaling these digits. This parameter MUST use one of the LINEDIGITMODE_Constants.

lpszDigits (4 bytes): An unsigned 32-bit integer. The offset, in bytes, in the VarData field of a null-terminated Unicode character packet that contains the digits to generate.

dwDuration (4 bytes): An unsigned 32-bit integer. Specifies both the duration, in milliseconds, of DTMF digits and pulse and DTMF interdigit spacing. A value of 0 uses a default value. The dwDuration parameter MUST be within the range that is specified by MinDialParams to MaxDialParams in LINEDEVCAPS. If out of range, the actual value is set by the service provider to the nearest value in the range. This parameter is not validated by TAPI when this function is called.

dwEndToEndID (4 bytes): An unsigned 32-bit integer. This unique request identifier MUST be stored by the server and passed back as dwParam2 of the corresponding LINE_GENERATE packet to the client when the digit generation is completed.

Reserved2 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved3 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved4 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved5 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved6 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved7 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved8 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

Reserved9 (4 bytes): An unsigned 32-bit integer. This field is used for padding and MUST be ignored on receipt. It can be any value.

VarData (variable): Contains a null-terminated Unicode character packet that is indicated in the lpszDigits field.

The contents of this field MUST be DWORD-aligned, as specified in [MS-DTYP] section 2.2.9.