MERLIN LEGEND Communications System Release 5.0
Feature Reference
555-650-110
Issue 1
June 1997
Features
Page 184
Digital Data Calls
If a videoconferencing system requires two B-channels but does not have an
ISDN-BRI interface (some older group video systems have V.35 interfaces, for
example), it may need to use the adjunct extension numbers of two different MLX
extension jacks.
Primary Rate Interface (PRI)
9
The ISDN (Integrated Services Digital Network) Primary Rate Interface (PRI) is a
standard access arrangement that can be used to connect the system to a
network providing voice and digital data services.
PRI is a standard access arrangement that uses a DS1 facility (also called a
pipe)
to support twenty-three 64-kbps data connections (known as
B-channels
) and one
64-kbps connection (known as a
D-channel
) used to convey signaling information.
Some PRI service allows only voice calls and does not support data. For more
information, see
‘‘Primary Rate Interface (PRI) and T1’’ on page 441
T1 Switched 56 Lines
9
A T1 facility can be connected to the MERLIN LEGEND Communications System
to supply a number of data and voice services. Release 4.0 and later systems can
support one Switched 56 (56 kbps) data connection on each Digital Signal Level 0
(DS0) channel of the T1 facility. There are twenty-four DS0 channels on each T1
facility. For more information, see
‘‘Primary Rate Interface (PRI) and T1’’ on page
Basic Rate Interface (BRI)
9
ISDN NI-1 Basic Rate Interface (BRI) is a standard access arrangement that can
be used to connect the system to a network providing voice and digital data
services. BRI is supported in Release 4.0 and later systems only. BRI supports
two 64-kbps data connections (known as
B-channels
or
lines
) for up to 128 kbps
data throughput. For more information, see the section
2B Data
9
The combination of two data-bearing channels (
B-channels
) allows ISDN-BRI
devices (such as desktop and group video systems with ISDN-BRI interfaces) to
connect to a single MLX port and make full 128-kbps connections using ISDN
NI-1 BRI or ISDN PRI B-channels, or make 112-kbps connections when
T1 Switched 56 facilities are used.
NOTE:
For more information about 2B data, see the
Data/Video Reference
.