KVM switch
Depending on the product, the switch may present native connectors on the device where standard keyboard, monitor and mouse cables can be attached.
Another method to have a single DB25 or similar connector that aggregated connections at the switch with three independent keyboard, monitor and mouse cables to the computers.
[citation needed] Today, most KVMs are controlled through non-invasive hot-key commands (e.g. Ctrl+Ctrl, Scroll Lock+Scroll Lock and the Print Screen keys).
Enterprise-grade devices interconnected via daisy-chained and/or cascaded methods can support a total of 512 computers equally accessed by any given user console.
For analog video, resolution and refresh rate are the primary factors in determining the amount of bandwidth needed for the signal.
The method of converting these factors into bandwidth requirements is a point of ambiguity, in part because it is dependent on the analogue nature and state of the hardware.
High-resolution and High-refresh-rate monitors become standard setups for advanced high-end KVM switches (specially with Gaming PC).
Modern hardware designs use active electronics rather than physical switch contacts with the potential to control many computers on a common system backbone.
Another problem encountered with mechanical devices is the failure of one or more switch contacts to make firm, low resistance electrical connections, often necessitating some wiggling or adjustment of the knob to correct patchy colors on screen or unreliable peripheral response.
Most active (electronic rather than mechanical) KVM devices provide peripheral emulation, sending signals to the computers that are not currently selected to simulate a keyboard, mouse and monitor being connected.
Some types of active KVM switches do not emit signals that exactly match the physical keyboard, monitor, and mouse, which can result in unwanted behavior of the controlled machines.
[11] KVM switch over IP extenders use a dedicated micro-controller and potentially specialized video capture hardware to capture the video, keyboard, and mouse signals, compress and convert them into packets, and send them over an Ethernet link to a remote console application that unpacks and reconstitutes the dynamic graphical image.
KVM over IP subsystem is typically connected to a system's standby power plane so that it's available during the entire BIOS boot process.
[10] There are performance issues related with LAN/WAN hardware, standard protocols and network latency so user management is commonly referred to as "near real time".
Access to most remote or "KVM" over IP extenders today use a web browser, although many of the stand-alone viewer software applications provided by many manufacturers are also reliant on ActiveX or Java.
Newer techniques in OPMA management subsystem cards and other implementations get the video data directly using the DVI bus.
