How is bandwidth used in KVM-over-IP systems?

Dominion KX III offers totally new video processing that provides flexible, high performance video, efficient use of bandwidth and anytime/anywhere access via LAN, WAN or Internet.

The Dominion KX III digitizes, compresses and encrypts the keyboard, video and mouse signals from the target server and transmits IP packets over the IP network to the remote client to create the remote session to the user. The KX III provides an at-the-rack experience based on its industry-leading video processing algorithms.

Screen changes, i.e., video accounts for the majority of the bandwidth used – and keyboard and mouse activity are significantly less.

It is important to note that bandwidth is only used when the user is active. The amount of bandwidth used is based on the amount of change to the server’s video display screen.

If there are no changes to the video – the user is not interacting with the server – there is generally little to no bandwidth used. If the user moves the mouse or types a character, then there is a small amount of bandwidth used. If the display is running a complex screen saver or playing a video, then there can be a larger amount of bandwidth used.

How does bandwidth affect KVM-over-IP performance?

In general, there is a trade-off between bandwidth and performance. The more bandwidth available, the better performance can be. In limited bandwidth environments, performance can degrade. The Dominion KX III has been optimized to provide strong performance in a wide variety of environments.

What factors affect bandwidth?

There are many factors that determine how much bandwidth will be used. The primary factor, noted above, is the amount of change in the target server’s video display. This is dependent on the user’s task and actions.

Other factors include the server’s video resolution, networking speed and characteristics, the KVM Client Connection Properties, client PC resources and video card noise.

How much bandwidth does KX III use for common tasks?

Bandwidth primarily depends on the user’s task and actions. The more the server’s video screen changes, the more bandwidth is utilized.

How do I optimize performance and bandwidth?

KX III provides a variety of settings in our remote clients for the user to optimize bandwidth and performance. The default settings will provide an at-the-rack level of performance in standard LAN/WAN environments with economical use of bandwidth.

Optimize For. Use this setting to configure the video engine for standard IT/computer applications or for video/broadcast applications.

Compression. Move the slider to the left for the highest possible video quality and to the right for the least amount of bandwidth.

Noise Filter. In most cases, the default setting will work best, however you can move to the left for more responsive video and to the right for lower bandwidth.

Other tips to decrease bandwidth include:

• Use a solid desktop background instead of a complex image
• Disable screensavers
• Use a lower video resolution on the target server
• Uncheck the "Show window contents while dragging" option in Windows
• Use simple images, themes and desktops (e.g., Windows Classic)

I want to connect over the Internet. What type of performance should I expect?

It depends on the bandwidth and latency of the Internet connection between your remote client and the KX III. With a cable modem or high speed DSL connection, your performance can be very similar to a LAN/WAN connection. For lower speed links, use the suggestions above to improve performance.

I have a high bandwidth environment. How can I optimize performance?

The default settings will work well. You can move the Connection Properties settings to the left for increased video performance.

What is the maximum remote (over IP) video resolution supported?

The Dominion KX III is the first and only KVM-over-IP switch to support full high definition (HD) remote video resolution – 1920x1080 at frame rates up to 30 frames per second with digital audio.

In addition, popular widescreen formats are supported, including 1600x1200, 1680x1050 and 1440x900, so remote users can work with today’s higher resolution monitors.

How much bandwidth is used for audio?

It depends on the type of audio format used, but to listen to CD quality audio, approximately 1.5 Mbps is used.

What about servers with DVI ports?

Servers with DVI ports that support DVI-A (analog) and DVI-I (integrated analog and digital) can use Raritan’s ADVI-VGA inexpensive, passive adapter to convert the server’s DVI port to a VGA plug that can be connected to a KX III CIM’s VGA plug.

Servers with DVI ports that support DVI-I or DVI-D (digital) can use the new D2CIM-DVUSB-DVI CIM.