What is a Call-Control Message?

Call-control (also called "client-control") messages are from client applications requesting, establishing, answering, controlling, or terminating calls on behalf of a specified agent phone and manipulating the telephony features associated with the agent’s phone.

These messages invoke a message response from the server. Consequently the messages are paired request/response messages. A request message for the desired control action is sent, and the outcome of the request is indicated by the type of response message that is received.

Depending on the specifics of the request, as much as 10 or 15 seconds might elapse before the response message is returned. A successfully executed request is indicated by the corresponding control-action confirmation message, while an unsuccessful request is indicated by a CONTROL_FAILURE_CONF message.

You can use call-control messages to do the following:

• Initiate a new call.

• Answer a call.

• Drop a call.

• Put a call on hold.

• Take back a call from the hold state.

• Put one call on hold and answer another call.

• Drop the connection to a consult agent and reconnect to the original call.

• Initiate a call transfer operation.

• Initiate a conference operation.

• Transmit Dual Tone Multi-Frequency (DTMF) tones, as for example, to enter a phone number or an account number.