LANs Unbound
By Lincoln D. Stein
Until recently, building an Ethernet-based LAN meant pulling cable through
walls, setting up hubs and punchdown blocks in telephone closets, and mastering
the art of crimping RJ-45 jacks to Category 5 cable. Although effective,
cable-based Ethernet has some disadvantages. When installing Ethernet in a new
building, you have to anticipate your network needs in advance. Because each
desktop machine and server has to be within a few feet of an Ethernet wall port,
the prudent thing to do is to install as many wall ports as you might ever
realistically need. My office, for example, has a total of six Ethernet ports,
even though I'll never use more than one.
Retrofitting Ethernet into an older building can be expensive, as holes have to
be drilled through concrete slabs and cables snaked through walls. After
installation, the results may not always be satisfactory. For example, I used to
work in a picturesque wood-frame office building that had a little problem with
rodents. Rats gnawing the cables was the single most frequent cause of network
outages. Apparently, PVC insulation is quite delectable! Even if you don't have
rats, cables are subject to damage from wear and tear, moisture, and improper
installation. Finding the damage and repairing it is a hassle.
Wireless networking changes all of that. Instead of pulling cable through walls,
you drop an access point box into the telephone closet, pop a wireless Ethernet
card into every desktop machine and laptop, and you've got a network. The
wireless network acts just like a wired Ethernet except that there are no
cables.
