Polycom RMX 2000/4000 Administrator’s Guide

Conferencing Modes

Standard Conferencing

When defining a new video Profile, you select the parameters that determine the video display on the participant’s endpoint and the quality of the video. When defining a new conference Profile, the system uses default values for standard conferencing. Standard conferencing enable several participants to be viewed simultaneously and each connected endpoint uses its highest video, audio and data capabilities up to the maximum bit rate set for the conference.

The main parameters that define the quality of a video conference are:

Bit Rate - The transfer rate of video and audio streams. The higher the bit rate, the better the video quality.

Audio Algorithm - The audio compression algorithm determines the quality of the conference audio.

Video protocol, video format, frame rate, annexes, and interlaced video mode - These parameters define the quality of the video images. The RMX will send video at the best possible resolution supported by endpoints regardless of the resolution received from the endpoints.

When Sharpness is selected as the Video Quality setting in the conference Profile, the RMX will send 4CIF (H.263) at 15fps instead of CIF (H.264) at 30fps.

H.264 protocol provides better compression of video images in bit rates lower than 384 Kbps and it will be automatically selected for the endpoint if it supports H.264.

When working with RMXs at low bit rates (128, 256, or 384Kbps), HDX endpoints will transmit SD15 resolution instead of 2CIF resolution.

When using 1x1 conference layout, the RMX transmits the same resolution it receives from the endpoint.

Lost Packet Recovery (LPR) - LPR creates additional packets that contain recovery information used to reconstruct packets that are lost during transmission.

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Polycom 2000/4000 manual Conferencing Modes, Standard Conferencing