Specifications

System Software Diagnostics Guide — September 2006 175
Glossary
ANI: Automatic Number Identification. A telephone service that provides the telephone number of an incoming
call. ANI is also known as Caller ID.
Automatic Number Identification: See ANI.
B channel: A bearer channel that carries the main data.
bit oriented : Communications protocols in which control information may be coded in a single bit.
CAS: Channel Associated Signaling. Signaling in which the signals necessary to switch a given circuit are
transmitted via the circuit itself or via a signaling channel permanently associated with it.
called ID: A telephone service that identifies for the receiver what telephone number was dialed by the caller.
This is also known as DNIS.
caller ID: A telephone service that provides the telephone number of an incoming call. Caller ID is also known as
ANI.
channel: A path of communication, either electrical or electromagnetic, between two or more points. Also called
a circuit, facility, line, link or path.
D channel: A channel that carries control and signaling information.
Dialed Number Identification Service: See DNIS.
DNIS: Dialed Number Identification Service. A telephone service that identifies for the receiver what telephone
number was dialed by the caller. This is also known as Called ID.
Integrated Services Digital Network: See ISDN.
ISDN: Integrated Services Digital Network. An integrated digital network in which the same time-division
switches and digital transmission paths are used to establish connections for different services. ISDN services
include telephone, data, electronic mail, and facsimile. The method used to accomplish a connection is often
specified: for example, switched connection, nonswitched connection, exchange connection, ISDN connection.
line loopback: A signal used to command the far-end receiver to loop back the received line signal.
loopback: A state of a transmission facility in which the received signal is returned towards the sender; a type of
diagnostic test in which the transmitted signal is returned to the sending device after passing through a data
communications link or network, which allows the returned signal to be compared with the transmitted signal for
troubleshooting purposes.
loop start: Seizing (starting) a line by bridging through a resistance the tip and ring (both wires) of a telephone
line. In residential installations, the loop start trunk is the most common.