KVM Switch

A KVM Switch allows the connection of a Keyboard, VDU (Video Display Unit) & mouse to multiple computers. The user determines which of various computers they require to take control of. It is a hardware tool that allows choice of individual computers or servers by means of a simple control technique using a simple dial or button.

Some KVM Switches can have the added capability to control associated USB devices & even speakers. Products utilizing Section twisted pair cable can be used to control equipment at distances up to 300 meters, often using some kind of manufacturer’s proprietary protocols.

A later innovation has been KVM over IP, where the KVM Switch conveys the control knowledge & captured keyboard, video & mouse signals by an IP over Ethernet link to a remote application. This greatly increases the range & scope of control over LAN, WAN & Serial Point-to-Point links. The common technique is to connect by a web browser using some kind of proprietary program, but security is an obvious issued. This is handled by implementing SSL (Secure Sockets Layer) with 128-bit encryption.

Organizations that have various dedicated servers may well opt to make use of KVM Switches to enable the servers to be monitored & controlled individually from a single tool. Administrators & operators can switch between physical server devices at the flick of a switch or push of a button.

Keyboard, Video & Mouse Switches comes in various formats including Desktop & Rackmounted models. These products come as Direct Connect systems, Networked systems & those that are controlled from a dedicated console. In addition to the KVM Switches most major manufacturers will normally have an extensive range of accessories such as interface modules, cable adapters & cable kits.

For some time now, VGA based switches have probably been the most popular format, but HDMI (High-Definition Multimedia Interface) & DVI (Digital Visual Interface) are quickly becoming efficient digital options to VGA.

DVI is a common digital standard that is popular for PC connections to display units & HDMI is an uncompressed digital standard for audio & video signals. It can pass both the video & audio down a single cable between such devices as DVD Players, Set-Top boxes & a digital TV.

Control connections on KVM switches are often PS/2, which was the common standard for mouse & keyboard connections for lots of years, & USB which is simpler & more flexible. Lots of Switches have the choice of either. The user has to keep in mind to buy the right cable types, unless they are supplied with the switch.