Workshop

Physical Maps
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Physical maps, of course, refer to the physical world—that is, how things really are. Because physical
maps are incredibly more detailed than logical maps, you’ll want to chew them off in bite-sized chunks.
Some sites can get away with just one physical map (usually fewer than 50 PCs in these cases). Most
sites usually need a physical map for each floor of the building. This is usually a good breakdown for
most sites, because it shows each and every wire running along with each and every PC, printer, switch,
and hub, and this can get rather large. Accordingly, for simpler sites, it’s really terrific to be able to lay
your hands on the architectural floor plan of your building and add the network wiring and wire closet
layout to it. A more complex site might also need more complex documentation in the form of a physical
segment map.
I refer to a network as a physical network or physical segment—a group of hubs that are connected
without a router or switch (in other words, the “party line”). Any hubs that are connected via a switch or
router are always considered separate physical segments. Large ones can need their own maps.
For example, Token-Ring (which I discuss in more detail in Hour 10, “Token-Ring Basics”) remains just
“one network” even though it can have many hubs attached to it and can span several offices without
using routers. Because the physical network is complex in this case, a separate physical segment map
would be appropriate (see Figure 2.3). No matter what type of network you have, a physical
documentation worksheet can act as a quick reference sheet for all data about that particular physical
network (see Figure 2.4).
Figure 2.3 A sample Token-Ring physical map.