Networking 101: Understanding Layers Aug 13, 2008, 22 :04 UTC (0 Talkback[s]) (4058 reads) (Other stories by Charlie Schluting)
"The physical layer, layer 1, is too often ignored in a classroom setting. It may seem simple, but there are aspects of the first layer that oftentimes demand significant attention. Layer one is simply wiring, fiber, network cards, and anything else that is used to make two network devices communicate. Even a carrier pigeon would be considered layer one gear (see RFC 1149). Network troubleshooting will often lead to a layer one issue. We can't forget the legendary story of CAT5 strung across the floor, and an office chair periodically rolling over it leading to spotty network connectivity. Sadly, this type of problem is quite common, and takes the longest to troubleshoot."
