A transmission control character used as a request for a response from the station with which a connection has been set up.
Note: The response may include station identification, the type of equipment in service, and the status of the remote station.

The OSI term for a layered-protocol machine.

The entrance to a building for both public and private network service cables (including antenna transmission lines, where applicable), including the entrance point at the building wall or floor, and continuing to the entrance room or entrance space. [After ANSI/TIA/EIA-568A]

In a building, the point of emergence of telecommunications service cables through an exterior wall, floor slab, or from a rigid metal conduit or intermediate metal conduit. [After ANSI/TIA/EIA-568A]

In a building, a space in which the joining of inter- and/or intrabuilding telecommunications backbone facilities takes place.
Note: An entrance room may serve also as an equipment room. [After ANSI/TIA/EIA-568A]

1. In cryptosystems, the deliberate planting of apparent flaws in a data processing system for the purpose of detecting attempted penetrations or for confusing an intruder about which flaws to exploit. [2382-pt.8]
2. [The] deliberate planting of apparent flaws in an information system (IS) for the purpose of detecting attempted penetrations. [INFOSEC-99]

E.164 NUmber Mapping

The boundary of the family of curves obtained by varying a parameter of a wave. See figure under amplitude modulation.

Signal distortion that results when the rate of change of phase shift with frequency over the necessary bandwidth of the signal is not constant.
Note: Envelope delay distortion is usually expressed as one-half the difference between the delays of the two extremes of the necessary bandwidth.

See air-conditioning.