Chapter 3-Video Protocols and Resolution Configuration for CP Conferencing
Polycom, Inc. 3-23
* It is recommend to set the endpoint to Motion to ensure the transmission of the higher frame rates of
25fps/30fps to the RMX.
‡ MXP 990/3000 endpoints transmit 576x448 pixels. Other MXP endpoints may transmit other
resolutions eg. CIF.

Content

Sharing and receiving Content is supported.
Bandwidth allocated to the Content channel during Content sharing may cause the video
resolution to be decreased as from w448p to w288p.
When Content sharing stops and the full bandwidth becomes available, video resumes at the
previous w448p resolution.
For more information see "H.239” on page 4-2.

Packet Loss Compensation

If there is Packet Loss in the network and Dynamic Bandwidth Allocation (DBA) is activated,
allocating bandwidth for Lost Packet Recovery, video resolution decreases from w448p
to w288p.
When Packet Loss ceases and DBA no longer needs to allocate bandwidth for Lost Packet
Recovery, the full bandwidth becomes available and video resumes at the previous w448p
resolution.
For more information see "Packet Loss Compensation (LPR and DBA)” on page 4-50.

Enabling Support of the w448p Resolution

w448p resolution support for Tandberg endpoints requires setting of the following entities:
•Tandberg endpoint
• RMX flags
•RMX Conference Profile

RMX System Flag Settings

•The System Flag USE_INTERMEDIATE_SD_ RESOLUTION must be manually added
to system.cfg with its value set to YES.
• The value of the PAL_NTSC_VIDEO_OUTPUT System Flag must be set to PAL.
If the System Flag is not defined as PAL, and if the current speaker is sending NTSC
video stream, the frame rate will decrease to 15fps. Setting the flag to PAL will ensure
that a frame rate of 25fps is maintained.
For more information about modifying System Flags, see "Modifying System Flags” on
page 22-1.
SIP and ISDN endpoints
The System Flag only affects endpoints that support SD resolution and for which the RMX
would have selected a transmission frame rate of 15 fps. Higher resolution endpoints are not
affected by this flag.
All SIP and ISDN endpoints (not only Tandberg MXP) are connected as if they are Tandberg
MXP causing the RMX to select w448p, because endpoint-type information from these
endpoints is not guaranteed during capabilities exchange.
For flag changes (including deletion) to take effect, the RMX must be reset. For more information,
see the "Resetting the RMX” on page 21-69.