Usually, a DVI extension isn't required to connect computer to a digital projector or monitor. If the monitor is located within a few feet of the computers backend, the typical monitor cable transmits the video signal satisfactorily. The problem arises when a digital monitor is located more than a few feet from the computer. That's when a DVI over CAT5 Extender is required to transmit the digital signals.
A Cat5/6 cable consists of 3 pairs of wires connected to an RJ45 connector. It is the preferred solution for local area networks where computers communicate across the wire to printers, servers, and other office equipment connected to the network. In most cases, Cat5/6 cables are satisfactory for connecting components to the network. When components are separated by a longer distance a Cat5 DVI Extender is used to boost the signal from computer to monitor.
Signals travelling down cables longer than 300 feet suffer loss of signal strength. Because of that, the network engineer has to plan the ports, seating and server room accordingly. It's not unusual for large monitors, projectors or similar display devices to be located quite a distance from the controlling computer. Three hundred feet adds up quickly when a computer is located in a secure room, but must connect to a monitor mounted in a lobby. That's when the Cat5 DVI Extension device must be connected to increase the range over Cat5 networks.
Distance Limitations of DVI Over CAT5 - DVI over Cat5 extenders vary in how much they can increase the Cat5/6 range. Distance limits depend on the device, how it is powered and if connecting more than one monitor. Some offer ranges of up to 50 meters, while other devices provide reliable video quality up to 100 meters. If you require a greater distance, then you probably are going to need to look into a Fiber Optic DVI Extender solution which enables user to extend the video signal over a single mode or multimode fiber optic cable. This Fiber extender kit consists in pair's transmitter and receiver. The transmitter unit connects to the source and the receiver units connect to the display.