Chapter 7 - Conference Types
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• Continuous Presence (CP) - A conference in which several participants
can be viewed simultaneously. In this type of session, each connected
endpoint uses its own highest video, audio and data capabilities. This
option also enables special video layouts to be selected for viewing the
conference participants. The following video layout options are
available: Classic, Quad Views and Software.
In Classic Continuous Presence conference, each participant uses a
different video port on the video card. This method enables such features
as full Transcoding per participant, Personal Layout (customized
Continuous Presence layout per participant) and maintenance of overall
video and audio quality for the conference - even when participants with
lower capabilities connect. However, in the Continuous Presence-Classic
video session, the number of participants is limited by the total number
of ports on the video cards installed in the MCU.
In Continuous Presence-Quad Views session, additional layouts intended
for large conferences (10+ participants) are available for selection. This
mode is available only with the Video+ card.
In Software Continuous Presence conferences, only two types of video
layout formats are available for selection: 2x1 and 2x2. If the conference
includes fewer than 5 participants, one of the layout windows is grayed
out. Software CP is a software solution for IP only conference that uses
fewer video card resource by combining four incoming QCIF streams
with fixed video bitrate from four different participants into one outgoing
CIF stream.
For a detailed description of CP conferences, see the MGC Manager
User’s Guide Volume II, Chapter 1, “Advanced Settings”.
Highest Common Mechanism
In Video Switching conferences, the Highest Common mechanism enables
the MCU to select the optimal video parameters for the conference according
to the highest video capabilities that are common to all the endpoints
participating in the conference.
The selected common video is dynamically adjusted with each participant
connection to and disconnection from the conference. Highest Common
mechanism is available with both H.320 and H.323 endpoints.
The Highest Common mechanism improves the connectivity between
endpoints, eliminate Secondary connections, and facilitates Entry Queue
Access and participant’s moves during conferences.