2.2.3.1.29 LINECALLSTATE_Constants

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The LINECALLSTATE_Constants are bit-flag constants that describe the call states that a call can be in.

Constant/value

Description

LINECALLSTATE_IDLE

0x00000001

The call exists but has not been connected. No activity exists on the call, which means that no call is currently active.

LINECALLSTATE_OFFERING

0x00000002

The call is being offered to the station, signaling the arrival of a new call. The offering state is not the same as causing a phone or computer to ring. In some environments, a call in the offering state does not ring the user until the switch instructs the line to ring. An example of this use might be where an incoming call appears on several station sets but only the primary address rings. The instruction to ring does not affect any call states.

LINECALLSTATE_ACCEPTED

0x00000004

The call was in the offering state and has been accepted. This indicates to other (monitoring) applications that the current owner application has claimed responsibility for answering the call. In ISDN, the accepted state is entered when the called-party equipment sends a packet to the switch indicating that it is willing to present the call to the called person. This has the side effect of alerting (ringing) the users at both ends of the call. An incoming call can always be immediately answered without first being separately accepted.

LINECALLSTATE_DIALTONE

0x00000008

The call is receiving a dial tone from the switch, which means that the switch is ready to receive a dialed number. See LINEDIALTONEMODE_Constants for identifiers of special dial tones, such as the stutter tone of normal voice mail.

LINECALLSTATE_DIALING

0x00000010

The originator must be dialing digits on the call. The dialed digits are collected by the switch. Note that the GenerateDigits packet will not place the line into the dialing state.

LINECALLSTATE_RINGBACK

0x00000020

The station to be called has been reached, and the destination switch is generating a ring tone back to the originator. A ringback means that the destination address is being alerted to the call.

LINECALLSTATE_BUSY

0x00000040

The call must be receiving a busy tone. A busy tone indicates that the call cannot be completed because either a circuit (trunk) or the station of the remote party is in use. For more information, see LINEBUSYMODE_Constants.

LINECALLSTATE_SPECIALINFO

0x00000080

The call must be receiving a special information signal, which precedes a prerecorded announcement that indicates why a call cannot be completed. For more information, see LINESPECIALINFO_Constants.

LINECALLSTATE_CONNECTED

0x00000100

The call has been established and the connection must be made. Information must be able to flow over the call between the originating address and the destination address.

LINECALLSTATE_PROCEEDING

0x00000200

Dialing has completed, and the call must be proceeding through the switch or telephone network. This action occurs after dialing is complete and before the call reaches the dialed party, as indicated by ringback tone, busy tone, or answer.

LINECALLSTATE_ONHOLD

0x00000400

The call must be on hold by the switch. This action frees the physical line, which allows another call to use the line.

LINECALLSTATE_CONFERENCED

0x00000800

The call must be a member of a conference call and is logically in the connected state.

LINECALLSTATE_ONHOLDPENDCONF

0x00001000

The call must be currently on hold while it is being added to a conference.

LINECALLSTATE_ONHOLDPENDTRANSFER

0x00002000

The call must be currently on hold awaiting transfer to another number.

LINECALLSTATE_DISCONNECTED

0x00004000

The remote party must have been disconnected from the call.

LINECALLSTATE_UNKNOWN

0x00008000

The call exists, but its state must be currently unknown. This state can be the result of poor call progress detection by the service provider. A call state packet with the call state set to unknown can also be generated to inform TAPI about a new call at a time when the actual call state of the call is not exactly known.

The high-order 8 bits can define a device-specific substate of any of the predefined states, provided that one of the LINECALLSTATE bits defined above MUST also be set. The low-order 24 bits are reserved for predefined states.

The LINECALLSTATE_Constants are used as parameters by the LINE_CALLSTATE packet that is sent to the application. The packet carries the new call state to which the call transitioned. These constants can also be used as members in the LINECALLSTATUS packet that is returned by the GetCallStatus packet.