The Dial packet is transmitted from a TAPI client to a TAPI server in a remote procedure call. Sending this packet dials the specified dialable number on the specified call.

Req_Func (4 bytes): An unsigned 32-bit integer. The identifier of the function that will be invoked on the remote server. This value MUST be set to 15.

Return Values

On completion of ClientRequest, this field contains the result of the encapsulated telephony request. A nonzero request ID value indicates that the request is in progress and will complete asynchronously, and a LINEERR_Constants value indicates synchronous failure.

Returns a positive request identifier if the function will be completed asynchronously or a negative error number if an error occurs. The dwParam2 parameter of the corresponding LINE_REPLY packet is zero if the function succeeds, or it is a negative error number if an error occurs. If the client specified a nonzero value in the dwRequestID field of the packet, the same value MUST be used for the returned positive request identifier. Common return values are as follows:

Name	Value
LINEERR_INVALCALLHANDLE	0x80000018
LINEERR_OPERATIONFAILED	0x80000048
LINEERR_INVALADDRESS	0x80000010
LINEERR_RESOURCEUNAVAIL	0x8000004B
LINEERR_INVALCOUNTRYCODE	0x80000022
LINEERR_DIALBILLING	0x80000008
LINEERR_INVALCALLSTATE	0x8000001C
LINEERR_DIALQUIET	0x8000000B
LINEERR_ADDRESSBLOCKED	0x80000053
LINEERR_DIALDIALTONE	0x80000009
LINEERR_NOMEM	0x80000044
LINEERR_DIALPROMPT	0x8000000A
LINEERR_OPERATIONUNAVAIL	0x80000049

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

dwRequestID (4 bytes): An unsigned 32-bit integer. The identifier of the asynchronous request.

hCall (4 bytes): An HCALL. The handle to the call on which a number is to be dialed. 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 except idle and disconnected.

lpszDestAddress (4 bytes): An unsigned 32-bit integer. The offset, in bytes, in the VarData field of a null-terminated Unicode string that specifies the destination to dial by using the standard dialable number format.

dwCountryCode (4 bytes): An unsigned 32-bit integer. The country code of the destination. The implementation uses this field to select the call-progress protocols for the destination address. If a value of 0 is specified, a default call-progress protocol that is defined by the service provider is used. TAPI does not validate this parameter when this function is called.

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.

Reserved10 (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 string that is indicated in the lpszDestAddress field.

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