Polycom RMX 2000 Administrator's Manual page 78

Chapter 6-Additional Conferencing Information
6-8
Simple cascade links do not declare H.239 capabilities. Content can only
be shared in the local conference.
The highest common Content bit rate is calculated for the conference each
time an endpoint connects. Therefore, if an endpoint connects to an
ongoing conference at a lower bit rate than the current bit rate, the
Content bit rate for the current conference is re-calculated and decreased.
Content Resolution and Bit Rate
The Content algorithm is H.263 Annex T, supporting the following
resolutions:
QCIF, CIF, 4CIF, VGA, SVGA, XGA and SD.
The Content channel can transmit one of the following modes:
• Graphics – default mode, for standard graphics
• Hi-res Graphics – requiring a higher bit rate, for high quality display
or highly detailed graphics
• Live Video – highest bit rate, for video clips or live video display
Bit rate allocation is dynamic during the conference and when the Content
channel closes, the video bit rate of the People conference is restored to its
maximum.
An endpoint cannot increase its bit rate but it can change its Content
resolution during a conference. The RMX can decrease the allocated
Content bit rate during a conference.
The following table shows the bit rate allocated to the Content channel
from the video channel in each of the three Content modes:
Table 6-3 Bit Rate Allocation to Content Channel
Conf Kbps
64/96
/ Mode
Graphics 0
Hi-res 0
Graphics
Live Video 0
128 256 384 512
64 64 128 128
64 128 192 256
64 128 256 384
768 1024 1472
256 256 256
384 384 512
512 768 768
1920
256
512
768