Networking Page 4


	Media

	Transmission media is how you get the job done. This is where the newbies are slow and the hacks are spending the $100/month to haul butt. It's like anything else; you get what you pay for. Network Administrators worldwide would love a blank check. We wouldn't have to worry about modems and performance. We'd just install the fastest, baddest and most overkilled solution available. Last time any of us checked, money does not come without end. It is then a question of need versus cost. Cable media is the most popular media by far. There are a couple choices on cable media. There is coaxial, twisted pair and fiber-optic cabling. First, let's look at coax. Coaxial cable is the oldest of the three. It looks like TV Cable but it's not. It is sometimes referred to as RG-58. There are two classifications of coax cable: Thinnet & Thicknet. Thinnet is 6mm in diameter while Thicknet is 13mm. Thinnet is more common than Thicknet in the real world.

Page 4

Page 1 - Introduction

Page 2 - A little history

Page 3 - OSI - not 'Oh Sports Illustrated!'

Page 5 - I feel the need....the need for speed.


	Thicknet does not bend as easy as Thinnet. The Thicker core means that it can transmit data further distances (500m). It is more expensive than Thinnet due to its larger size. Electromagnetic interference (EMI) is a big problem for any copper-based wiring. This means don't run any cable over florescent lights or near nuclear power plants. Thicknet is a bit funkier than Thinnet.


	Twisted Pair cabling is the most common networking cabling you'll see. It's cheap, it's fast and it is so easy to install. It comes in two flavors: Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP). The shielding is used to reduce EMI. The shielding is an extra cost. The twisting of the wires prevents attenuation (signal loss). This is good. A great many people (including myself) will want to untwist the cable when putting the connectors on the end. Don't do this. This is bad. UTP cable is the most common of the already common twisted pair cable. It's everywhere. It comes in 5 grade categories: CAT1-5. CAT5 is very common nowadays and is very inexpensive. There's hardly ever a reason to purchase anything else, but I'm sure someone can find a reason. Fiber optic is the ideal media. It's basically a well refined plastic and glass core surrounded by light reflecting material. The sender sends single color pulses of lights and the receiver interprets those pulses. Fiber is fast. And speed is the next topic. On to Page 5.