Lucent Technologies MERLIN LEGEND 6 - Manual (Page 124)

MERLIN LEGEND Communications System Release 6.0
System Manager’s Guide
555-660-118
Issue 1
February 1998
System Components
Page 3-42 Adjuncts
3
In Release 4.0 and later systems, you can program (see System Programming for
more information) an MLX extension jack for 2B data. This allows some
communications equipment, such as desktop videoconferencing systems and the
Ascend Pipeline 25-Px or Ascend Pipeline 50, to use both B-channels of an MLX
extension jack to make and/or receive 2B calls. To use 2B data, the MLX port
must be programmed for this capability. Extensions for MFMs or data
communications equipment not supporting 2B data, such as ISDN terminal
adapters, should not be programmed for 2B data.
Videoconferencing Systems 3
The system supports videoconferencing systems with these types of interfaces
and built-in DCE or data communications adjuncts:
■ ISDN/BRI. Beginning with Release 4.0, the system supports desktop and
group videoconferencing systems that connect to a single MLX port and
support speeds of 56 kbps or 64 kbps over digital facilities. Using the
system’s 2B Data feature described later in this topic, both B-channels of
the MLX port are used to support 2B data calls, at speeds of 112 or 128
kbps (not all video systems support all speeds). These installations do not
require separate data communications equipment (DCE).
■ V.35. Older group video systems with a V.35 use either an inverse
multiplexor (IMUX) or two ISDN terminal adapters as their DCE. Some
systems include the DCE, and some require separate data
communications equipment. With a V.35 interface, a video system must be
connected to two MLX extension jacks; it uses the adjunct extensions of
each jack to send and receive video calls over two B-channels at speeds of
112 or 128 kbps, depending on the video system and digital facility.
Passive Bus 3
Some desktop videoconferencing systems allow the extension to include an MLX
telephone connected directly to the desktop video system. In this configuration,
the desktop video system can use both B-channels for 2B data video calls, as
long as the MLX telephone is not making or receiving a call.
If the desktop video system supports 1B data, it can make or receive a call using
only one B-channel while the MLX telephone is on a call. One B-channel is not
generally adequate for video, but some desktop video applications can switch to
two channels once the MLX telephone is not on a call.
NOTE:
See “Desktop Videoconferencing” on page 5–22 and “Group
Videoconferencing” on page 5–23 for more information about
videoconferencing applications.