Content Transmission Methods - Polycom realpresence 1800 Administrator's Manual

Content Transmission Methods

There are two methods used for content transmission:
● Content Video Switching
● Multiple Content Resolutions - Content Transcoding
Content Transcoding is not supported by Collaboration Server (RMX) 1800 with no DSP cards.
Note: Content in RealConnect Environments
In conferences using Polycom® RealConnect™ technology between remotes premises, content is
shared using Polycom® ContentConnect for Microsoft environments.
In this scenario, content sharing requires one of the following:
• Content transmission method is set to Multiple Content Resolutions, with the H.263 check-box
selected.
• H.264 Cascade Optimized (see
• H.264 HD (likewise)
Content Video Switching
When using this method, content sent by endpoints is transmitted as-is to all content-capable participants.
The content rate is determined using one of the following methods:
● Highest Common
● Fixed Rate
LPR has no effect on content rate, though due to the increased number of frames, video rate is
decreased.
Highest Common
This method is applied for single MCU conferences.
The Highest Common method is applied in a few levels:
● Within the same protocol - The highest common content rate
● Between protocols - H.263 and H.264
● In H.264 - Base and high profile
In this method, the content rate is negotiated to highest common capabilities supported by the endpoints
connected to the conference. Therefore, if the conference includes participants supporting both lower and
higher content capabilities, the content is sent to all endpoints using the lowest endpoint capabilities.
Note, that for H.263 content, the MCU negotiates the content rate, and the endpoint sharing the content
determines the resolution and frame rate. However, for H.264 content, the MCU negotiates profile type,
content rate, resolution and frame rate, and the endpoint sharing the content may use lower content
parameters.
Polycom®, Inc.
MCU Usage Modes of Content
Sharing Content During Conferences
Protocols)
128