Chapter 4-Additional Conferencing Information
Polycom, Inc. 4-9
• Endpoints that do not have at least H.263 capability can connect to the conference but
cannot share Content.
• This option is not available in SVC Conferencing Mode.

H.263 (AVC Only Conferences)

Select this option when most of the endpoints support H.263 and some endpoints support
H.264. In such a case, all endpoints will share content using the H.263 protocol, and this
protocol will not change throughout the conference (fix mode).
Bit rate allocation to the Content channel by the RMX is dynamic according to the conference
line rate and Content Settings selected for the conference. For more information see "Content
Settings” on page 4-7.
This option is not available in SVC Conferencing Mode.

H.264 HD (AVC Only Conferences)

The H.264 HD option should be selected only if most endpoints in the conference support
H.264 to ensure high quality Content.
When this protocol option is selected, endpoints must connect at Content bit rates above a
minimum as specified by specific System Flags to ensure high quality Content for all
participants. For more information about System Flags see "Setting the Minimum Content Rate
for Each Content Quality Setting for H.264 HD” on page 4-9.
Bit rate allocation to the Content channel by the RMX is dynamic according to the conference
line rate and Content Setting selected for the conference. For more information see "Content
Settings” on page 4-7.
Endpoints that do not support H.264, or these that do not meet the minimum line rate
threshold for the Content Setting along with ISDN endpoints, are connected as Legacy
Endpoints and receive content through their video channel. If the Send Content to Legacy
Endpoints selection is disabled these endpoints will not receive content.
Guidelines
• Only endpoints that support H.264 capability at a resolutions of HD720p5 or higher will
be able to receive and send Content.
• This option is not available in SVC Conferencing Mode.
• When H.264 HD is selected, the Send Content to Legacy Endpoints selection is enabled by
default in the Conference Profile – Video Settings tab.
•In MPM+ Card Configuration Mode, maximum supported content resolution is HD 720p.
• Once an endpoint is categorized as a Legacy Endpoint and receives the content over the
video channel, it remains in this mode without the ability to upgrade to H.264 HD
content and receive content over the Content channel.
• The minimum Content Rate required for allowing a participant to share Content is the
lower valued parameter when comparing the System Flag setting (Table 4-5) and the
content bit rate allocation derived from the conference line rate (Table 4-3).
When the flag settings enable an endpoint to share Content at a content rate that is
lower than the conference content rate (Table 4-3), the content rate of the entire
conference is reduced to the content rate supported by that endpoint.
Setting the Minimum Content Rate for Each Content Quality Setting for H.264 HD
The following System Flags determine the minimum content rate required for endpoints to
share H.264 high quality content via the Content channel.