Polycom 8 manual Highest Common Mechanism

Chapter 7 - Conference Types

•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.

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