“Each of the network switches we use in a rack has at least 48 ports,” writes Kevin Hazard at the SoftLayer blog. “Now consider that each rack has two public network switches, two private network switches and one out-of-band management network switch that need to be connected to every SoftLayer server in the rack. That’s 240 pre-measured network cables that need to be labeled and routed to specific heights in each rack … without getting tangled and knotted up (see: behind your TV or under your computer desk). The cabling process is so precise that if a single cable is out of place, the zip-tie on an entire bundle will be cut, and the process is started from scratch.”
Here’s a video of the rack cabling process, which runs about 4 minutes.