AT&T MERLIN LEGEND Release 3.1, System Programming Manual

Page: 866 / 887

Glossary
System Programming
GL–19
N
network Configuration of communications devices and software
connected for information interchange.
network interface Hardware, software, or both that links two systems in an
interconnected group of systems, for example, between
the local telephone company and a PBX.
O
off-hook Telephone is said to be off-hook when the user has lifted
the handset, pressed the
Speaker button to turn on the
speakerphone, or used a headset to connect to the
communications system or the telephone network.
off-premises
telephone See OPT .
ones density Requirement for channelized DS1 service to the public
network that eight consecutive zeros cannot occur in a
digital data stream.
on-hook Telephone is said to be on-hook when the handset is hung
up, the speakerphone is turned off, and the user is not
using a headset to connect to the communications system
or the telephone network.
OPT (off-premises telephone) Single-line telephone or other
tip/ring device connected to the system through an 008
OPT module in the control unit. Appears as an inside
extension to the system, but may be physically located
away from the system.
OPX off-premises extension
out-of-band
signaling Signaling that uses the same path as voice-frequency
transmission and in which the signaling is outside the band
used for voice frequencies.