In a perfect world, network engineers and people who design and manage networks should focus on what they want the network to achieve instead of the device-level interactions. In my first job as an intern for a local ISP, wide-eyed and excited, I received my first assignment to install a router on a customer's site to turn up their fractional frame relay link (remember those?). How would I do that? I asked. I was handed a standard operating procedure for turning up frame relay links. I went to the customer site, blindly typed in the commands and looked at the green lights flash, and then I happily packed my bag and patted myself on the back for a job well done. As exciting as that first assignment was, I ...