Polycom® RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator’s Guide
2-14 Polycom, Inc.
The video streams displayed in the conference layout on each endpoint is obtained from the
different streams received from each of the endpoints displayed in the layout. Depending on
the size of the video cell in the configured layout, the endpoint requests the video stream in
the required resolution from the RealPresence Collaboration Server. The higher the display
quality and size, the higher the requested resolution will be sent to the endpoint. The
endpoint creates the displayed layout from the different video streams it receives.
For instance, an SVC endpoint might want to receive three video streams at different frame
rates and resolutions, and create a conference layout with the received video streams. Each
SVC-enabled endpoint sends encoded SVC bit streams to the MCU to relay to the other
SVC-enabled endpoints in the conference.
The endpoints encode the video in multiple resolutions and decodes the multiple video
input streams.
For example:
RealPresence mobile client (2) will transmit two resolutions; one that is suited for
RealPresence Desktop client (3) and a second that is suited for two other endpoints:
RealPresence Desktop client (4) and (1).
RealPresence Desktop client (1) transmits two resolutions; one that is suited for
RealPresence Mobile client (2) and a second that is suited for RealPresence Desktop
client(4).
The MCU determines which of the incoming resolutions to send to each endpoint. It does
not perform any SVC encoding and decoding, or any transcoding of the video streams. The
RealPresence Collaboration Server functions as the multipoint media relay to the endpoints.
For voice activated selection of the video streams, the RealPresence Collaboration Server
determines which of the incoming bit streams to send to each endpoint.
Advantages of SVC Conferencing
SVC increases the scalability of video networks and enables mass desktop video
deployments. Some of the advantages of SVC conferencing are:
• Offers high-resolution video conferencing with low end-to-end latency, improved error
resiliency and higher system capacities.
• Allows the SVC-enabled video endpoints to manage display layouts, supporting
multiple line rates, resolutions and frame rates.
• The RealPresence Collaboration Server functions as a media relay server providing low
cost production benefits. The RealPresence Collaboration Server reduces bandwidth
usage by only selecting the necessary video stream to be sent to the endpoints.
Guidelines
• SVC conferences are supported only with the following:
—RMX systems with MPMx card
—CP Licensing
—SIP over UDP signaling
—SIP over TLS Signaling
Although SVC Conferencing Mode options are available in Conference Profiles, it is advised that
they not be used with Version 8.1.4.J.