KVM Switching Steps Back to Move Ahead

The simple concept of sharing keyboards, monitors, and mice with multiple CPUs has evolved into the smart way to control server farms. One vendor stays ahead of the group with new products and concepts...

 By Jim Freund
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It was a simple enough concept to begin with: Often, folk had two or more CPUs, and saw no need to buy extra keyboards, video monitors, or mice, much less waste the desktop real estate the additional peripherals would take up. Thus, the KVM (Keyboard, Video, Mouse) switch was born. Network managers took this one step further: Why not make the server headless (that is to say, without a monitor), and use the KVM switch to access it?

After that, the next step was obvious. By using remote access software to connect to the server, you didn't need to run cabling from the server to your KVM switch. This, however, presented a conundrum: If the server crashed and wouldn't reboot, the remote access software was useless. So a new kind of KVM switch was born -- one that would actually allow the network manager to view the server remotely even without its booting up. In this way, the manager could access the BIOS and change the boot order if needs be; for example, if there was a non-boot floppy in the A: drive.

As networks grew to the size where server farms became an accepted topology, it was clear that KVM switching was the most practical way to access and manage individual servers. Even though we are no longer replacing the keyboard, video or mouse, but rather employing a one-to-many method of accessing servers, the quaint name of KVM switching has remained, reminding us of the roots of this technology. (When was the last time you actually *dialed* a phone?)

Two leading vendors, Apex and Cybex, were competing to supply solutions in this space, and caused a stir in July 2000 when the two companies merged to form Avocent. The company has been garnering praise ever since. The basic premise of their technology is to capture the analog signals from the associated keyboards, monitors, and mice; convert them to digital packets; and then compress the signals (which can be otherwise unwieldy) and transmit them securely over TCP/IP using encryption.

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This article was originally published on Dec 12, 2001
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