in-use lamp
Issue 1.0 May 2003
411
Integrated Services
Digital Network Basic
Rate Interface (ISDN-
BRI)
The interface between a communications system and terminal that includes two 64-
kbps B-channels for transmitting voice or data and one 16-kbps D-channel for
transmitting associated B-channel call control and out-of-band signaling information.
ISDN-BRI also includes 48 kbps for transmitting framing and D-channel contention
information, for a total interface speed of 192 kbps. ISDN-BRI serves ISDN terminals
and digital terminals fitted with ISDN terminal adapters. See also
Integrated Services
Digital Network (ISDN)
on page 410 and
Integrated Services Digital Network Primary
Rate Interface (ISDN-PRI)
on page 411.
Integrated Services
Digital Network Primary
Rate Interface (ISDN-PRI)
The interface between multiple communications systems that in North America
includes 24 64-kbps channels, corresponding to the North American digital signal
level-1 (DS1) standard rate of 1.544 Mbps. The most common arrangement of
channels in ISDN-PRI is 23 64-kbps B-channels for transmitting voice and data and
1 64-kbps D-channel for transmitting associated B-channel call control and out-of-
band signaling information. With nonfacility-associated signaling (NFAS), ISDN-PRI
can include 24 B-channels and no D-channel. See also
Integrated Services Digital
Network (ISDN)
on page 410 and
Integrated Services Digital Network Basic Rate
Interface (ISDN-BRI)
on page 411.
intercept tone
An tone that indicates a dialing error or denial of the service requested.
interface
A common boundary between two systems or pieces of equipment.
internal call
A connection between two users within a system.
International
Telecommunications
Union (ITU)
Formerly known as International Telegraph and Telephone Consultative Committee
(CCITT), ITU is an international organization that sets universal standards for data
communications, including ISDN. ITU members are from telecommunications
companies and organizations around the world. See also
BX.25
on page 393.
International Telegraph
and Telephone
Consultative Committee
See
International Telecommunications Union (ITU)
on page 411.
interflow
The ability for calls to forward to other splits on the same PBX or a different PBX
using the Call Forward All Calls feature.
intraflow
The ability for calls to redirect to other splits on the same PBX on a conditional or
unconditional basis using call coverage busy, don’t answer, or all criteria.
internal measurements
BCMS measurements that are made by the system. ACD measurements that are
made external to the system (via External CMS) are referred to as external
measurements.
in-use lamp
A red light on a multiappearance voice terminal that lights to show which call
appearance will be selected when the handset is lifted or which call appearance is
active when a user is off-hook.
