The traditional method of accessing individual computers in a large server room was the “crash cart”. When a server went down or needed updates, the crash cart was rolled out to the physical location of the server. The keyboard, mouse and monitor on the cart were then connected to the server and the required maintenance was done. This was obviously a time consuming way of managing a large server farm, even when a technician was on site. This changed with the use of large capacity single user KVM switching systems that allowed for daisy-chain style expansion, but in the long run, the required rack space and massive cable requirements of these KVM systems prompted the need for more elegant solutions.
Along comes KVM via IP, KVM over IP, “remote KVM” or “remote access”. This advance incorporated the existing network connections on each computer to be used as a “window” into the server from which one could have keyboard, mouse and video access via LAN or internet. In the beginning, such solutions were slow and buggy in that the bandwidth required to transmit the video from the remote computer was huge. This caused very slow refresh rates and difficulty tracking the mouse accurately. The load on a network could be substantial and in some cases required a separate network just for the remote access, mainly in multi-user environments. Manufacturers began to address this issue by using video compression technologies (for example Dambrackas Video Compression™ - DVC) similar to those used to compress video on the computer. Areas of the screen that are not changing are left static, while only that which is changing is transmitted. The latest models have a very responsive feel and high reliability.
Many different variations of the remote access concept are available. Some are console based units that simply hook onto an existing KVM system, translating the analog keyboard, video and mouse data into packetized network protocols. Others combine the console with the traditional KVM switch into a single chassis. Still others interface with the computer directly via a remote access PCI card that essentially places a hardware webserver within the computer for control of all aspects of the system including boot-up and power management. Combined with a virtual drive, these units can even reinstall an operating system via IP. Powerful indeed!
In the mean time the traditional KVM switching also underwent some changes. The use of individual cables for each keyboard, video and mouse port on each computer changed to a now standard 3-in-one style of cable. Each manufacturer has their own implementation, but the basic design is essentially the same. Still, even with low profile connectors and unified cables, there was still a bulk factor that many found cumbersome. Enter KVM via Cat 5.
