Cabling has been always an important issue in every building but in Data Centres is quite a decition that could force a new investment in few years if it is not the proper one. Lets take TIA 942 as the reference for the cabling; there you can find that the cabling architecture is quite simple (the same as a Telecomunication Rooms in a Building); so the key is to lay those cables that will be from the racks battery where the routers, switches, modems are deployed to such cabinets where the servers or SAN will be set. This cabling will remain with no MACs (movements, additions and changes) and could be copper or fiber; so if we have planned that the cabling will be useful for at least five to seven years; we MUST choose the late generation in cooper systems (Category 6A or CLASS F -ISO designation) But what kind of category 6A F/UTP or just UTP? There are a bunch of manufactures that offer both kind of types and some that only have the UTP. You can revise the technical issues that grant one or other as the best for the job, trasmitting 10 gps - Fibre Channel will use this ethernet option quite soon- Other point to be consider is the pathways. As the new SCS going to Cat 6A or Class F those trays or ladders have to be as wide as the raised floor support pedestal grid permit; so the elevation of those grid became an issue to take in consideration when are you designing the data centre cabling. Cabling Performace is the main concern whe you chosse the SCS nowdays the 40 and 100 gps trasmitting equipments are knocking the door, so the cabling should be prepare for. Most of us could think , "when in heaven are we going to have such transfer speed as a need? well when I started in this industry ARCnet was the LAN protocol that hit the market (1985) and Token RING (4 Mps) was the new wave with IBMs PCs. So what can I figure is that 100 Gps could catch us in 4 to 5 years. If we have to design a DATA CENTRE´s infrastructure to be ready for such speeds ; I can suggest that we have to observe those SCS that can give us the chance to switch in few weeks from one speed to the higher one. Observe class F and of course Fiber Optics is "other tale..."
roberto sanchez, RCDD