by Juan van Heerden

You have probably all played some type of game via the Internet or your modem, and wished that you had a cheaper, better and faster way to accomplish the same thing. In this article, I am going to give you a a better alternative – networks. In this series, I am going to tell you about the two major types that are used today, how to set them up, the costs involved, the pros and cons and how to set up the software for peer-to-peer and client/server.

Read this part and decide which type of network you want to use. Part 2 will cover how to install a UTP network’s hardware and part 3 will cover BNC. You must read this Part 1, but you’ll only read either part 2 or part 3, depending on which type you choose. Depending on the feedback, I will make a part 4, 5 and 6 that will cover how to install the drivers and set up your OS to use the network. Also, I might want to do a part 7, which I will answer any questions you might have asked me via e-mail while I wrote this series of articles.

The Two Types
Today, there are two major types of network architectures available, UTP and BNC. In the following sections, I am going to explain what that stands for, give you more jargon to memorize, etc. UTP stands for Unshielded Twisted Pair. Not many people these days know what BNC stands for anymore, I’m not sure what the real one is myself, but one of the many names is British Naval Connector.

UTP (10BaseT)
You’ve seen telephone wires – well that’s UTP – not the type used in computer networks though… the type in computer networks are cat 4 or cat 5 (category). The type telephone systems work with is cat 3. If you take a closer look at the telephone wires, you will notice there are 4 strands of wire inside the lead. They are actually rolled up in pairs of two; that is where the name comes from. Now – if you know anything about telephone systems, you should know that only two wires out of the four are used. Don’t ask me why, but that is the way it is – I think it might be for use as a backup, but if the first pair of wires gets broken, you have to rewire the plugs at the end(cut them off and recrimp it with different wire configuration). With cat 4 or cat 5, it is the same. There is 8 strands of wire inside the lead, and only 4 are used(#1&2, #3&6).

PROS

Well understood technology
Extremely cheap wiring
Easy to manage and add workstations
If one computer goes down, rest of network not affected
Extremely reliable
CONS

Expensive support electronics(e.g. hub)
Susceptible to line-noise
Limited distance
When hub breaks, entire network goes down
I want to explain one point in the pros section. When one computer goes down, only the computer goes down, the rest of the computer will still work fine, because as you can see, the network is arranged in a star topology. Each computer can still “talk” to the hub, and thus still “see” the network and “talk” to each other.

This line-art schematic shows a UTP network with 3 workstations and one server. The server doesn’t need to be there, if you have a peer-to-peer network, you only have as many workstations as you want, or as many as the hub you bought supports (typically 8). The point I am trying to show you, is that the one workstation is not connected to the hub, its wire got disconnected by accident the night before by the janitor, while cleaning. See that all the other workstations still have a direct line to the server, and they will thus continue to work without any problems.

Now, some more facts about a UTP network.

Any line, between a PC and a hub, must be less than 100m and more than 2m.
The wire is less expensive than BNC
It uses expensive hubs(less than $100, but you don’t need one with BNC)
If you already chose UTP, I have two things to tell you: 1.) Shame on you – you didn’t even read the BNC part, how do you know this one is best… 2.) Good choice – if you have the money, go for it.

BNC (10Base2)
I’ve seen many books tell people that BNC is the type that is used for television… Sometimes it is, but not always… In fact it is usually only used with the high-quality services, like cable and satellite. The normal stuff is RG-62 (I think). That was also used for networks, but for the old Arcnet type and nobody uses that anymore. There is only one type of this that exists, that I know about, and that is RG-58 wire. BNC actually refers to the connectors at the end.

PROS

No expensive support electronics(e.g. a hub)
Soft, thin and flexible wire – easy to install
CONS

Expensive wire
Hard to change configuration or add new computers once it is installed
If one computer goes down, the whole network goes down
Hard to diagnose problems
Extremely unreliable (makes you wonder why they used it as much as they did)
Relatively immune to line noise
Now, I’ve explained the part in with UTP about why only one computer goes down and the rest will stay up – well, now I’m going to explain why if one computer goes down, the whole network goes down. I do this, because I think this is extremely important in “mission-critical” situations.

Before I go on, I think I should explain how a BNC network works… When data gets sent from a workstation to one next to him, it always send the data in one direction. The data travels along the cable, until it gets to the last computer and hits the terminator. It then rebounds and goes back, and past the PC that sent it, and to the computer that needs the data. It can also happen that the destination PC is busy, and can’t read the data. In a case like that (it happens often), the data goes to the other terminator and bounces back. It does this a couple of times, until the data just disappears. The reason it disappears, is because the data loses strength each time it bounces off the terminator. Of course, if the data goes in the right direction, and it reaches the destination computer, before it reached the terminator, the computer will read the data and “remove” it from the data bouncing around on the network.

Now, back to my original story. The reason the network won’t work when the line is cut is because inside a cable for BNC (and UTP as well), there is always a complete “circle”, like a electric cord. If it doesn’t make a circle, the data can’t move. I am not going to explain this in detail – if you are interested, you should go and do a course in networking (or electronics). Basically, the data will just “fall out of the wire”. This is an EXTREMELY basic description of how it works, and I simplified it a lot. I have also left out a lot of the less-important parts.

I also said it is hard to diagnose what is wrong if a BNC network breaks. Well, if a wire breaks, then all the computers goes down. You don’t know which wire broke, you have to test all of them. Sure – it’s easy with a small network, but when you get to about 4 workstations and up, it starts turning into a nightmare. With UTP it’s a lot easier – one computer went down, you know which wire or which network card is the culprit.

Here are some facts:

It can only be 185m between the first computer and the last.
You can only have a maximum of 30 computers on one segment like that.
You can connect two segments, up to a maximum of five, but I am not going to tell you how to do it, this is supposed to be a beginners tutorial.
The wiring is expensive
There is not support electronics, so this one is actually cheaper than UTP
Your choice now – Conclusion
Now, I gave you enough information to make an educated decision about which network type to use. Think now, and read part 2 or 3, depending on which one you chose. Do yourself a favour: don’t just get the cheapest, or the most expensive. Use the type of network that fits ALL your needs.

Lastly – wait for part 2 & 3, don’t try to install everything now, before you know about anything – you don’t even know what to buy yet. I am going to tell you in the sections that deals with the specific parts. It can become tricky, and you don’t have anyone to help you with a problem, since I am going to IGNORE any pleas for help before I have both part 2 and 3 out. Another thing… I don’t take any responsibility for any damages incurred while trying to install a network, but if you follow my steps EXACTLY, there won’t be any problems. Have fun, enjoy!!

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