Group Videoconferencing - AT&T MERLIN LEGEND Release 3.1 System Planning Manual

About Data and Video Communications

Group Videoconferencing

A group videoconferencing system consists of a video camera, an audio unit,
and a display screen (such as a television) that connect to a CODEC. The
CODEC converts the analog voice and video signals into digital form for
transmission, and converts the digital signals received back into analog form.
The CODEC may use either a BRI interface to connect directly to an available
MLX port on a 408 MLX or 008 MLX module, or a v.35 interface to connect to an
ISDN terminal adapter (such as the ExpressRoute 1000 or 7500B data module)
which in turn connects to an MLX port.
NOTE:
When using the 008 MLX or 408 GS/LS-MLX module for data or video, you must
use Version 28 of the module.
When the group videoconferencing system uses a BRI interface, or an ISDN
terminal adapter that supports 2B Data, the video system may be connected to
a single MLX port that has been configured as a 2B Data port. This allows the
video system to use both B-Channels assigned to the MLX port, thereby
achieving the high-speed data connection necessary to support full-motion
video.
If the group videoconferencing system uses a v.35 interface to connect to an
ISDN terminal adapter that does not support 2B Data, then two ISDN terminal
adapters are required (each connecting to a separate MLX port that has been
configured as a 1B Data port) in order to achieve a 2B Data connection.
NOTE:
Do not connect equipment, such as an ISDN terminal adapter or G4 FAX
machine, that does not support 2B Data to an MLX port that has been
configured as a 2B Data port. This wastes system resources and may cause
other system errors.
The network facilities used by the endpoint connected to the MLX port may be
any combination of PRI, T1 Switched 56 (both provided by the 100D module),
and/or NI-1 BRI (provided by the 800 NI-BRI module) facilities, however it is
recommended that you use two B-channels of the same type to ensure the best
possible connection. See Figure 5-6 for a sample connection diagram.
Data Communications
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