by Adam Kuban
A device which connects peripherals including a single keyboard, video and a mouse to multiple systems is called a KVM Switch. By eliminating clutter and saving space, these devices have made it very simple to control multiple computers with a single set of peripherals. Typically, a user can connect computers ranging in number between 2 to 32, but by daisy chaining, the switches access can be increased by up to 256 Servers. Equipped with the ability to control both PS2 and/or USB devices, these units are available in a variety of categories such as, KVM over IP and the CAT5 switches.
Form factors for the KVM switch include: 2, 4, 8, 16 and 32 port versions. This range of sizes allows them to be used in environments such as homes and small offices where a single user needs to control as few as two PCs with a 2 port KVM Switch; to large data centers where hundreds of servers may be involved and requires cascading multiple switches. Working on plug and play functionality, these devices do not have any complex installation procedures. They do not require any additional software for start up and switching between PCs can be done via front panel push buttons, keyboard commands, on- screen display or RS232. Supporting multiple platforms, they can be used with Windows Vista/2003/XP/2000, Linux and UNIX operating systems.
Depending upon the connection type, these switches can be classified into digital DVI KVM Switch or Analog, such as the VGA 4 port KVM Switch. Some variants are also available with audio and microphone options and include the ability to switch audio from each PC that is connected and transmit the sound to a set of peripheral speakers. Providing VGA video resolution up to 1600 x 1200, these switches also face the distance limitation since the placement of peripherals is restricted by the cable lengths. In order to overcome these limitations, the KVM over IP solution was introduced.
The KVM switches add greater flexibility, control and access to systems in any configuration. It is therefore used in various environments like financial, educational, recreational, business, government and commercial establishments.