At its core, Cisco collaboration device’s bandwidth management technology is designed to automatically adjust the amount of data that is sent between devices based on the available bandwidth. This means that if your network is experiencing congestion or other bandwidth constraints, the device automatically adjust its transmission settings to ensure that the media quality is optimized within the available bandwidth.

This is accomplished through several different mechanisms, including dynamic adjustment of video resolution, frame rate, and audio quality. For example, if network bandwidth is limited, the device may automatically reduce the resolution of the video being sent or decrease the number of frames per second to reduce the amount of data being sent.

In addition to these automatic adjustments, Cisco collaboration devices also include several manual bandwidth management settings that can be configured through xAPI or Control Hub. These settings allow you to specify minimum and maximum bandwidth thresholds, which limit the amount of bandwidth that can be used by specific devices.

Recommended configuration

While Cisco Webex's bandwidth management technology is designed to optimize media quality within available bandwidth, it's important to note that higher bandwidth availability can result in better media quality even in challenging network environments. We recommend that you configure the maximum allowable bandwidth for Webex devices whenever possible.

By configuring the maximum allowable bandwidth, you allow the device to fully leverage the available network resources, which can result in higher resolution video and audio, faster transmission rates, and overall better performance. This can be important in scenarios where high-quality media performance is critical to the success of a meeting or collaboration session.

The following settings are found under the Conference section of a device’s configuration page in Control Hub.

• In cases where a call is subject to multiple configured bandwidth constraints, the lower is always applied.

• Newer devices¹ have a higher maximum value for Max Transmit Rate and Receive Call Rate.

• Call rate includes the bandwidth that is used for audio, video, and content sharing in a meeting.

For configuration descriptions, visit roomos.cisco.com.

With RoomOS 11 February 2023 release, the upper bound on the value space for these settings were increased 6000–20000 kb/s. To prevent side effects on the networks of existing deployments, the default value has been kept at 6000 kb/s. Despite this, we recommend setting the value to its maximum of 20000 kb/s for nearly all use cases, including those where the physically available bandwidth is less.

Low bandwidth scenarios

Cisco collaboration devices are designed to work seamlessly across a range of network conditions, including low bandwidth or high latency connections, meaning media quality adjusts automatically to maintain an optimal user experience. If you wish to manually configure the maximum allowable bandwidth consumption for Cisco collaboration devices, note that there's a recommended minimum bandwidth of 4000 kb/s, to ensure good quality for main video and content video use cases.

This threshold is important because it represents the minimum bandwidth that is required to support high-quality Full-HD video (1080p) streams with a frame rate of 30 frames per second for the main video and content streams. While Cisco collaboration devices support video conferencing at lower bandwidths, the end-user experience is improved for a large proportion of use cases around this threshold.