Video Conference Attributes; Video Session Types - Polycom MGC-100 Getting Started Manual

Video Conference Attributes

Video Conferences can include both Video and Audio as well as Audio Only
participants. In a video session, participants can connect to the conference
using different network connections: ISDN, IP (H.323 and SIP) and MPI
(serial connection). A conference is defined for all the interface types.

Video Session Types

The video session type determines the video display options (full screen or
split screen with all participant viewed simultaneously) and the method in
which the video session is processed by the MCU (whether all participants
connect using the same line rate and video parameters without using video
resources, or each one uses the endpoint's capabilities).
Video Switching - A conference in which all participants see the same
•
picture (video). The current speaker is displayed in full screen on all the
participants' endpoints, while the speaker sees the previous speaker. The
feature enabling Switching between participants is voice-activated.
Whenever participants start to speak, they become the conference
speaker and are viewed on all screens. Since this conference type does
not use video card resources, all participants in the conference must use
the same line rate and video parameters such as Video Protocol, Frame
Rate, Annexes and Interlaced Video mode.
In Video Switching conferences, the Highest Common Mechanism can
be enabled for the video parameters. This allows the system to select the
best video parameters that can be supported by all the endpoints
currently connected to the system, and to dynamically change them when
a new endpoint joins or leaves the conference. (see also MGC Manager
User's Guide, Volume II, Chapter 1, "Setting Large Video Switching
Conferences").
Transcoding - A conference in which participants can use different line
•
rates and video, audio and data formats while maintaining the highest
video and audio capabilities that they can achieve with their endpoints.
As in Video Switching sessions, the current speaker is displayed in full
screen on all the participants' endpoints. Switching between participants
is voice-activated. Because each video participant is connected using the
highest possible video quality, this conference type requires appropriate
Video+ card resources for processing inputs from the different endpoints.
Chapter 4 - About Conferences
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