Best of RAH:
Take Us to the Promised LAN
by Dave Bealer
This commentary first appeared in the January 1993 issue of Random
Access Humor. The version you are about to read, which was edited for
brevity, was published in the September 1994 issue of Network News.
Copyright © 1993-94 Dave Bealer, All Rights Reserved.
Every year since 1985 has been touted by industry pundits as "The
Year of the Network." Now, networks are everywhere. Calling 1994 "The
Year of the Network" is kind of like calling it "The Year of the Automobile."
You've either got one or you wish you did.
Everyone today knows that LANs are the solution to everything from payroll
to the common cold. What most people don't know is how all this network
The OSI from ISO
Way back in the 1970s the International Sadists Organization (ISO),
located in Paris, France, noticed that it had an image problem. For years
people had gazed in awe at the mighty computing machines run by serious men
in white laboratory coats. But suddenly, some upstarts were actually building
"personal computers" in their basements and garages. In response to this
threat to their technical sovereignty, the ISO formulated the Operational
Sadistic Interface (OSI). Obviously the ISO had a lot to learn about
Basically, the OSI was about networks. The theory was that if some twerp
was going to make computers themselves easy to use, a good way to make
computers impossible to understand was to make it necessary to hook all the
computers together. Cleverly avoiding the more simple single-level networks,
the ISO adopted the layer principle, which has worked so well for Betty
The layers of the OSI are as follows: Physical, Data-link, Transport,
Hysterical, Devonian, Triassic and Application. Geologists search
through the layers of network sediment to find the fossils buried
within: Acoustically coupled modems, S-100 computers, CP/M, Ethernet
(Oops! Sorry...that one is still alive and kicking), the Timex Sinclair
and the Apple Lisa.
All of these creatures of the computing world failed at networking in
one way or another. All of them except ethernet, which has been
successful as a species for a long time, even if it hasn't changed
much. Ethernet is the horseshoe crab of network technology.
Three major types of LAN exist: Ethernet, Arcnet and Token Ring.
Ethernet. This one almost never got off the ground because users kept
passing out from ether fumes until a reliable method of sealing the cables
was found. Ethernet has the advantage of having been around forever, so it
has been made to work, however unwillingly, with a wide range of computing
Arcnet. This type of network, which is inexpensive and quite
serviceable for small workgroups, is especially preferred by welders.
Token Ring. Token Ring was created by J.R.R. Token, the celebrated
"Lord of the Ring." A little known, interesting fact is that J.R.R. Token is
the husband of Madeline Token, the Secretary of Vaporware Corp. Token Ring
is popular with large installations because response time is not significantly
degraded when more stations are added. Of course it couldn't get much slower.
Let's Get Physical
The signals generated by all logical LAN formats must travel between stations
on the the network by way of cables. Four major types of cabling are used in
LANs, each designed for a specific audience:
Coaxial Cable. Coax is familiar to most people as the same kind of
cable which brings Cable TV into their homes. Coaxial cable creates some
unique opportunities for the future, such as a single coaxial link which
could bring both a network connection and "The Brady Bunch" to a single
high definition monitor. Coax allows fast data transfer and sports shielding,
which reduces interference from other signal sources like coffee makers, sun
lamps, Game Boys, and other common office equipment.
Unshielded Twisted-pair (UTP). Often mistaken for plain telephone wire
by repair people and for Twizzlers by children, UTP is cheaper than coax but
offers nearly the same data transfer rates. Because it lacks shielding, UTP
appeals to networkers who like to live dangerously.
Shielded Twisted-pair (STP). Similar to UTP but with shielding, STP
is preferred by organizations that practice safe networking.
Fiber-optic Cable. The fastest of all cable alternatives, fiber-optic
cable is sealed so squeamish users won't see the unspeakable things being done
to the light within.
The cables which carry the signals in a LAN cannot be randomly laid
out as the network is built, even though that is inevitably the way
it will appear. A lot of agonizing goes into the design of the logical
layout, or topology, of a new network. Some of this agonizing is even
There are three major network cabling topologies: Star, Daisy-chain
and Bit Bucket. No matter which topology is planned, the network almost
always ends up with a Bit Bucket topology.
Network Operating Systems
Every LAN requires a network operating system (NOS) in order to
function. Operating systems (OSs) such as MS-DOS and OS/2 (which rarely
operates) are not able to access devices on another machine in a network --
although they do have the advantage of occasionally accessing data which has
no origin on Earth.
This is where the NOS comes in. By collaborating with the device drivers for
the Network Interface Card (NIC) in the user's computer, the NOS tricks the OS
into thinking that the hard disk in Fred's PC down the hall is really the
Q: drive in the user's machine. Of course, PC operating systems are among the
more gullible pieces of software you will ever encounter. They are quite
forgetful as well, even to the point of misplacing disk drives that really
are connected to the machine in which they "operate."
A LAN in Every Pot
So what does the future of networking hold? Will Ethernet survive into the
true Cyberage? Perhaps one day mankind will network itself into one gigantic,
communal intelligence. When that happens, we may finally solve one of the
ancient riddles that has plagued the great thinkers since Socrates: how many
system administrators can fit on the head of a 24-pin dot matrix printer?
Dave Bealer is a fifty-something mainframe systems programmer who
works with CICS, z/OS and all manner of nasty acronyms at one of the
largest heavy metal shops on the East Coast. He shares a waterfront
townhome in Pasadena, MD. with a cat who annoys him endlessly as he
assiduously avoids writing for and publishing Random Access Humor.
Dave can be reached via e-mail at:
I'm at the corner of Walk and Don't Walk.