keyboard, video, mouse (KVM)
A KVM switch is a switch that allows multiple computers to be managed from one or more workstations. The KVM switch switches the keyboard (K), monitor (V) and computer mouse (M) together from one personal computer( PC) or server to another.
All input functions are performed by the keyboard and computer mouse; display is performed on the monitor, which is switched to the respective personal computer simultaneously with the keyboard and mouse. The control indicators located on the KVM switch show the active connection. Switching from one personal computer to another can be done by a key combination or automatically.
To meet modern security requirements, KVM switches must have built-in security features and be controllable over long distances. The length restrictions of the various interfaces must be taken into account. KVM extenders can be used to extend these length restrictions. Distances of up to 30 m can be bridged via Cat-5 cables, and even up to 10 km via fiber optic cables. If the cable quality is not sufficient, TP cables of the higher categories 6 and 7 can also be used. The runtime differences of the twisted wires, which lead to color distortions on the displays, can have a disadvantage at long distances. KVM extenders can compensate for these skew effects. FOC extenders work with multimode fibers up to 500 m, and with single- mode fibers for longer distances up to 10 km.
Cascading of several KVM switches can be considered if several personal computers (PCs) or servers are to be managed from one console.
The advantage of the KVM switch is the elimination of superfluous screen workstations and the greater clarity. Depending on the design, up to 16 computers can be managed from one KVM switch. These can be deployed locally or remotely and connected via data networks or as KVM-over- IP( KVMoIP).