Cisco Cisco WebEx Meeting Center WBS30 White Paper
© 2015 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information.
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Network Adaptation
All video resolutions listed in Table 4 are the default target resolutions. They are based on the assumption of a
perfect network environment. In the video engine design, Cisco has implemented network adaptation to promote
smooth transition from lower-quality to higher-quality video, and conversely. Between the default target resolutions,
fps, and bandwidth (90p, 180p, 360p, and 720p), you can send and receive other temporary resolutions to allow
graceful adaptation of the video quality to current conditions.
Bandwidth Bottleneck Detection
One of the most common network problems is insufficient or unreliable bandwidth. Bandwidth limitation can cause
packet loss, delays, and jitters. In addition, if the required sending and receiving bit rates exceed the bandwidth
limitations of the network, network congestion will occur and eventually results in a poor video experience. During
the video session, the client software closely monitors the transmission and packet-loss rates through the Real-
Time Transport Control (RTCP) feedback protocol. When changes in network conditions are detected, the quality-
of-service (QoS) module allocates bandwidths for a voice over IP (VoIP), data, and video session. The video
session then adjusts the outgoing bit streams through encoder control. After the network condition becomes stable,
the QoS module, together with the encoder control module, upgrades the video experience if the bandwidth allows
it. This QoS prioritization is for the WebEx client software operation.
Dynamic Parameters
The bandwidth bottleneck detection is a function to probe the current bandwidth capability by sending and
receiving network test packets. The probing results are used to guide the network adaptation process as described
in the previous section. In general, bandwidth bottleneck detection is at:
●
The start of a meeting
●
When the video start or stop button is pressed
●
Before upgrading video resolution to the next level that involves a significant bandwidth gap
Collaboration Meeting Room Hybrid
Cisco TelePresence
®
integration with the Cisco WebEx Meeting Center web conferencing service can enable
transparent voice, video, and data sharing between Cisco TelePresence environments and remote Cisco WebEx
users. This integration extends the reach of a Cisco TelePresence meeting to remote participants.
Figure 8 shows a picture of the participants list with a Cisco WebEx Enabled TelePresence meeting as viewed by
the WebEx participant and meeting information screenshot.