IT folks are the umpires of the enterprise -- nobody notices them until they screw up. To stretch that metaphor further, network cabling is the playing field of the organization, and people think about network cables about as often as baseball fans consider the blades of grass in left field.
I was talking to an old friend and superb wiring guy the other day who observed that nobody talks about wiring. He's right. Yet wiring is absolutely critical to a reliable network. And wiring problems are among the most difficult to troubleshoot, due to the intermittent issues that poor wiring can cause.
So what's to be done? Plenty. For starters, if you're rewiring an existing building, take the time to pull out the old wiring. It's terrifying to pop open a ceiling tile only to find 30 years of nasty wiring all over the place. I've done that in some buildings and found bundles of thicknet, Cat 3, and coaxial that nobody could identify. It probably tripled the overall effort to troubleshoot wiring issues to the edge.
Another good idea is color coding. It makes plenty of sense at the patch panel and in the datacenter, but it also makes sense at the edge in a different way. Running bulk cable to each box is a no-brainer, but especially if you're wiring for VoIP, put a small colored sticker next to the VoIP port and another next to the data port. In environments where VoIP is handled as a trunk with the phone acting as a switch for the PC, this isn't really relevant, but for other installations it simplifies IT support calls.
In the closets and the back room, make sure to invest in proper cable management and find a wiring contractor that can show you plenty of cabling porn -- pictures of a closet cable waterfall of several hundred drops that looks like a painting, or cable management schemes in dense closets that were obviously difficult to wrangle, but resulted in an easily managed layout. These are the hallmarks of a solid contractor, and the work they do will need to stand the test of time -- it's never a good idea to skimp on this part of the overall plan.
If you need justification on why you should be very cautious and selective on wiring and wiring contractors, buy a beer for someone who's been through a wiring disaster or a contractor who sees them on a regular basis. When the wiring goes wonky, it's like a circus funhouse of problems with no apparent connection that constantly plagues an otherwise solid IT infrastructure: users who can sometimes connect, sometimes not, complaints ranging from slow network access to poorly functioning applications and intermittent network outages that cannot be explained by any hardware or software issues. It's the stuff of nightmares.
Or you can just ask me. At one point many years ago, while dealing with exactly the issues I stated above, I finally walked into the datacenter one evening with a wiring crew and ripped out every patch cable in one edge aggregation rack -- something like 256 copper ports. We rewired the entire rack that night, and every one of the bizarre problems plaguing that side of the building disappeared. It would have been cathartic to set fire to the old patch bundles in the parking lot, but we figured that wouldn't be environmentally sound, and at the time the company actually got some money back selling the cabling for scrap. Luckily this problem was in the patch cabling and not the cabling to the jacks -- that would have been a much, much bigger and more expensive problem.
The moral of this story is simple: It doesn't matter what gear you're running or how reliable and expensive it is if the connections to the network are bad. Spend a little extra time and effort on your wiring and sleep better at night.