Going the Distance
There is a catch, however, that some people don’t realize. That 100m number includes all the way from a terminating device, such as a switch, to the end device, like a PC or IP camera, including patch cables.
Essentially, what the specification actually says is that the “horizontal” distance (the actual distance of cable inside the walls and above the ceiling) is 90m, leaving 10m for patch cables at each end. Don’t think you can put that wall jack exactly 100m away from the patch panel in the MDF room. You have to account for the additional distance between that wall jack and the PC/camera, and between the patch panel and the switch.
And no, just to be clear, the EIA/TIA specifications do not allow you to just crimp an RJ45 connector on the ends of the cable and plug it right in. It must be terminated to a patch panel or punch block matching the cable’s category certification.
Following the procedures outlined here for cable installation will go a long way toward passing any certification tests your customer might require. For more information on training and certification, check out Building Industry Consulting Service Int’l (BICSI) at www.bicsi.org.
Category Cabling Standards
Cat-1: Currently unrecognized by TIA/EIA. Previously used for POTS communications, ISDN and doorbell wiring.
Cat-2: Currently unrecognized by TIA/EIA. Previously was frequently used on 4Mbps token ring networks.
Cat-3: Currently defined in TIA/EIA-568-B, used for data networks using frequencies up to 16MHz. Historically popular for 10Mbps Et
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