There are several vendors of IP based KVM’s. Avocent is one of the better known KVM vendors. If you can reach the KVM’s via an IP address, then you can connect to them, whether that takes place over the LAN, WAN, or even public Internet. There is not usually a client that is used, but there can be. In most implementations of IP based KVM’s that I have used, you simply connect to the KVM via a web browser. Some sort of Java plugin or something similar is used to view the console of whatever machine or machines are attached to the KVM. I love IP based KVM’s. They save a lot of time and travel and will work just fine as long as you have a decent network connection between your system and the IP based KVM.