Polycom DOC2230A - Manual (Page 79)

Chapter 4 - About Conferences
4-3
Video Conference Attributes
There are four general types of video conferences:
• Video Switching - A conference in which all participants use the same
video and audio formats. Whenever a participant starts to speak, the
participant appears on all endpoints in full screen display as the
conference is a voice activated video switching conference.
• Transcoding (requires Video card) - A conference in which participants
use different video, audio and data formats, while maintaining the
highest video and audio capability each participant can achieve with his
or her codec. Like video switching, the current speaker is displayed on
all endpoints in full screen.
• Continuous Presence (requires Video card) - A conference in which
several participants can be viewed simultaneously. In this type of
conference, the highest video, audio and data quality for each participant
depends on the participants endpoint capabilities.
In a traditional 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 Layouts (individualized
Continuous Presence layouts per participant) and maintenance of overall
video and audio quality for the conference—even when participants with
lower capabilities connect. However, this method limits the number of
Continuous Presence participants to the number of ports on the Video
card, which is six.
• Conference On Port (requires Video card) - A conferencing method
suitable for large Continuous Presence conferences or when several
Continuous Presence conferences are running on the MCU.
In Conference On Port, all conference participants use a single video
port. This method allows for more than six participants to join a
Continuous Presence conference and allows for up to six Continuous
Presence conferences to be run on the MCU.
In a Conference on Port conference, a video layout can be selected for
the conference, but all the participants, including the speaker, view the
same layout and the same participants. The Personal layout selection is
not available in Conference on Port and the video quality is determined
by the highest common video parameters and by the video line rate.