If that title doesn’t get you motivated to read this article nothing will! I’ve been teaching a course in LAN design and it is really theoretical so the things that you need to know always figure that the best case scenario is what you’ll get. So here’s what you absolutely need to know about network cables.
Types and speeds :
Twisted Pair Cable
First, there’s twisted pair copper wire, chances are this is the stuff that connects your computer to the web (unless your’e browsing this from work on a high speed network). Twisted pair takes it’s name from the pattern that the wires have with two wires being twisted around each other to reduce electrical interference from nearby wires. The speeds that can be achieved range from 10Mbps to 10Gbps. This is what you probably refer to as ‘network cable’.
Concentric Cable (Coaxial)
Next, there is coaxial cable, which is also made of copper wire , however, the wires run concentric ( see the image to the left ). This cable is usually used to bring you television via your cable provider, and if you get internet from them then guess what, this is your cable. One thing that always surprises people is that when you use the cable company as your internet provider you ‘share’ the bandwidth with your neighbors. This means that speeds may vary depending on the number of people that are online. Your cable modem that cost you a good deal more than say a regular router actually has to change tour digital signal from the computer into an analog signal to be sent over the shared connection. Speeds with this type of cable are in the tens of Mbps.
Finally we get to fiber optic cables, this is the new kid on the block, as copper wire dates back to the telegraph. These cables are small glass tubes where pulses of light are sent so as you can imagine speeds are very very fast. The speed of light is 3.00 x 10^8 m/s. Let’s put that into perspective, you could travel from New York to Los Angeles (2462 miles) about 75 times in one second (186,000 miles an hour). Of course your data won’t seem like it travels quite as fast but that is due to the various delays a packet encounters on the road to NY or LA depending on where you are at.
Fiber Optic Cable
Now that we got the three main types of wire down consider this …
So designing a network is like building a nascar car right? It’s all about speed, and being lightweight helps a lot in that area right. A lot of emphasis is placed on the speed of fibre optic cable but let’s not overlook the security benefits of fiber optic cable opposed to cat5 and wireless communication methods.
There are a few things that can happen between the endpoints on a network that could compromise your data. These include:
Tapping - We have all seen those old spy films where someone climbs a telephone pole and taps into the phone wires to listen in on conversations, and we have seen the films where the someone is listening in on radios to intercept messages.
Well, since fibre optic cable is comprised of a bundle of glass tubes, now imagine how hard it is to tap into those tubes without breaking the connection or causing loss that is noticeable.
I dug up this article in the Washington Post that illustrates this with a few interesting stories regarding cables that have been cut during the construction around Tyson’s Corner.
Radiation - You lose data due to interference from electromagnetic radiation, and the amount of resilience you have to this issue is based on your cable choice, fibre optic being the best and twisted pair being the worst.