Patch panels are used to provide flexible connections between horizontal station cables and the equipment ports in the wiring closet. Patch panels have modular jacks that are connected so that they correspond to work area outlet jacks or to equipment ports. An example of patch panels is shown in above Figure. The ports on LAN equipment, such as hubs, often use 8-pin modular (RJ-style) jacks, so it is easy to connect a port to a patch panel by using a modular equipment cord (or patch cord). This provides sort of a natural LAN connecting environment, where all connections that the user makes involve familiar modular jacks and cords.
Patch panels are easy to install and are a little less confusing to the user than punchdowns, because each jack on the horizontal wiring patch corresponds to an identical jack at the workstation outlet. Patches also provide easy access, quick connections, and clear circuit marking (at least until they become covered with patch cords). Another aspect often overlooked is that adds, moves, and tests are all accomplished without using any tools. If appropriate wire management devices are used, the patched network can really be kept quite neat.
Patch Panel Specifications
A patch panel intended for LAN wiring use has an array of modular jacks that are mounted in a metal panel. The panel is generally wide enough to mount directly in a 19-in equipment rack, while its height varies with the number of jacks on the panel. Panels may be of any size, with multiples of 12 to 24 jacks being common. Patch jacks often correspond to punchdown block connections, which dictate the multiple-of-12 convention. For example, a group of twelve 4-pair circuits can be accommodated by both sides of a 66 block (50 pairs), whereas a group of twentyfour 4-pair circuits can be accommodated by a 100-pair 110 wiring block. Additionally, the number 24 is convenient to use, because a row of 24 modular jacks fits nicely across a 19-in panel width.
The connectors on a LAN patch panel are standard 8-pin modular jacks, wired either to T568A or B. The connections for station cables at the rear of the panel are usually color coded by pair number, which corresponds to the wiring pattern at the jack. It is possible to use other wiring patterns for special applications, but that isn’t covered here. The connectors are spaced according to the manufacturer’s preference, and you may find individually spaced connectors or connectors that are placed in groups of four or six adjacent jacks. The connectors are usually numbered according to their position on the panel. Optional circuit marking is described later in this section.