Mitel Inter-Tel 5000, Installation And Maintenance Manual

Page: 363 / 468

Chapter 6: Reference
Glossary
Inter-Tel
®
5000 Installation Manual – Issue 2.4, May 2008
Page 6-41
Glossary
Table 6-26 defines terms used in this manual to describe networking and related Inter-Tel
applications.
Table 6-26. Networking Terminology
Term Definition
2B+D A circuit divided into two 64 kbps B-channels that can carry voice, video, or data. It also
has a 16 kbps D-channel for low-speed data and signaling. There are two types of 2B+D
interfaces that use different wiring: the “U” interface uses a single twisted pair and the “S/
T” interface uses two twisted pairs. This circuit is also known as Basic Rate Interface
(BRI).
23B+D A circuit divided into 23 B-channels (64 kbps each) that can carry voice, data, and video
simultaneously. It also has a 64 kbps D-channel for out-of-band signaling, call control,
and packet data. This interface connects with two twisted-pairs of wire. This circuit is also
known as Primary Rate Interface (PRI).
The Inter-Tel system does not support use of the D-channel for packet data.
30B+D The standard European ISDN interface. A 30B+D circuit is divided into 30 B-channels
(64 kbps) that can carry voice, data, and video simultaneously. It also has a 64 kbps D-
channel for out-of-band signaling and call control, and one framing channel. This
interface uses two twisted-pairs of wire.
Automatic Call Number
Identification (ANI) Identifies the caller’s telephone number. The system receives a specified number of
digits. *ANI* is another type of ANI that does not require a specified number of digits.
The system receives a star (*) before the ANI digits to signal the beginning of the caller’s
telephone number. Then there is another star after the digits to signal the end of the ANI
information.
B-Channel The B-channel, or “bearer” channel, is the basic component of ISDN interfaces. A
B-channel can transmit or receive voice or data at up to 64,000 bits per second (64
kbps).
B-Channel
Negotiation
(Currently not
supported on Inter-Tel
5000 platforms.)
This allows the system to request the channel that will be used for each call. When the
system requests a specific B-channel for an outgoing call, the network decides which
channel will be used. However, if the channel selected by the network is not the
requested-channel, the system will release that channel (if seized) and attempt to re-
initiate the call using the channel specified by the network. (For an incoming call, the
system does need to request a channel.)
Bandwidth The bandwidth of a device determines the frequency range it can handle. Different types
of communications use different bandwidths. For example, telephone communication
requires a relatively narrow bandwidth, while video requires a wide bandwidth.
Basic Rate Interface
(BRI) Also called 2B+D, BRI provides two 64 kbps B-channels that can carry voice or data and
a 16 kbps D-channel for low-speed data and signaling. This can be used for homes and
Centrex sites that do not require PRI.
Calling Party Number
Service Provides the calling party’s line number (not billing number) to the called party.
D-Channel The data channel, or D-channel, carries the signaling information at 64 kbps for the
B-channels in a Primary Rate Interface or at 16 kbps in a Basic Rate Interface.
D-Channel Backup
(Currently not
supported on Inter-Tel
5000 platforms.)
Because the D-channel supports the other channels in the ISDN network, loss of the
D-channel would cause loss of access to the ISDN circuits. D-channels can be backed
up to provide protection in the event of D-channel loss. D-channel backup is especially
important in Non-Facility Associated Signaling (NFAS), because the D-channel supports
all of the B-channels in the
entire network.