C

call classification

TAPI process that reports changes in the type of media stream (voice, fax, data modem, and so on) to participating applications.

call progress monitoring

The process of listening for audible tones such as a dial tone, special information tones, busy signals, and ringback tones to determine the state of a call (its progress through the network).

call redirection

A function that allows an application to deflect an offering call to another address without first answering the call. Call redirection differs from call forwarding in that call forwarding is performed by the switch without the involvement of the application; redirection can be done on a call-by-call basis by the application, for example, driven by caller ID information. It differs from call transfer in that transferring a call requires that the call first be answered. See also called-ID, caller-ID, redirecting ID, redirection ID.

called-ID

Identifies the original destination address of a call. See also call redirection.

caller-ID

Identifies the originating address of a call. See also call redirection.

central office

Telephone company's local facility that provides telephone service in a specific area. Typically, subscribers' lines are joined to switching equipment that connects other subscribers to each other, locally and over long distance. Also called CO.

Centrex

A business telephone service offered by a local telephone company from a local, central office.

computer-centric connection

A connection that uses a computer add-in card or external box that is connected to both the telephone network and the phone set. Compare phone-centric connection.

connected-ID

Identifier for the party to which the call was actually connected. This may be different from the called party if the call was diverted.