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Embed code for: Fundamentals of Networking Unit two Discussion Board
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Fundamentals of Networking
Instructor Stephen Osborne
By: Wesley Millikin
August 26, 2015
Networks are an integral part of life today all over the world. They help us conduct business, connect with family and friends, and even help us go to college. In the not so distant past though, networks were uncommon in homes and other places. Probably the very first network was the DARPA (Defense Advanced Research Projects Agency) network in the early 1960’s. But since then networks have spanned the globe and connect household devices making networks very popular.
Networks need a way to connect each device and this is called network media. Media falls into two categories: wired and wireless. Wired media include coaxial cables, shielded twisted-pair wires, and fiber-optic cables. Wireless media include infrared and microwave. Traditionally, wire-based media is more popular in local area networks (LANs), while wireless media is popular in wide area networks (WANs). In newer networks, however, infrared and low-power radio media are becoming important in LANs (2013 M.U.S.E.).
With wired and wireless media, computers need a Network Interface Card (NIC) to be able to translate signals that are transmitted to it from another computer, or to transmit signals to a computer. The signals are then translated so the computer can understand what is being transmitted. The NIC used depends on what type of wired or wireless setup is used for the network. For instance if you have twisted pair wiring you would use an Ethernet NIC, if you use wireless technology then you would have a wireless NIC.
There are three different kinds of wired media that are used in networking. The first and probably the oldest is the coaxial cable. This cable is hardly implemented any longer but there are still older networks that are still in use today. Coaxial cable consists of a center core that is usually made of tin coated with copper which is just a very stiff and thick wire. Then it has a PVC sheath that protects it from the next layer which is a metal mesh alloy of one kind or another that is used for grounding to keep interference down. Then it has a final plastic sheath to protect it. It can have two styles of connectors, one will screw on like cable television and one will push in and twist to lock it in place this is known as BNC. And although there are different views on what BNC means I will just call it British Naval Connector.
The next type is twisted pair wiring called either category Cat3, Cat5, Cat5e, and Cat6. These can be unshielded twisted pair (UTP), or shielded twisted pair (STP). The UTP is more susceptible to EMI or electromagnetic interference than the STP. When it is run above the work area or below in a raised floor it must be nontoxic when burned, therefore it is known as plenum grade. All Cat3, 5, 5e, and 6 have eight wires that are twisted in pairs to reduce crosstalk and other interferences. This is the most common type of network connectivity and is used in most all networks that are setup today. It is relatively cheap and very flexible which makes it ideal for large networks. And depending on how a network is connected it is relatively easy to diagnose problems. All four categories connect with the same type of connector called an RJ-45 which looks like a phone jack but just a little bit wider.
Twisted pair can be wired two different ways. Straight through and crossover, straight through is what is used when a computer connects to a hub or a switch on a network. This allows it to communicate with the rest of the network. The crossover method is used when you want two computers to communicate with each other. This accomplished by the way the wires are positioned in the connector and if you don’t know how a system is setup all you have to do is look at where the wires are in the end of the connector.
The final wired media isn’t even a wire. It is called Fiber-optic and its core is made of glass or plastic. It then has a PVC sheath protecting it and then a plastic sheath on the outside. Fiber-optic is very expensive and not used for large networks except for the backbone and that’s only if you can afford it. Fiber-optic is immune to EMI because it is not electrical signals. It uses a laser or light pulses to send signals. The computer has to have a Fiber-optic NIC in order to be able to receive or transmit these signals. They are very expensive also and are used mostly when there is high traffic on a network. The connectors are similar to those used with coaxial and those used with twisted pair. Depending on what NIC is in the workstation.
M.U.S.E., My Unique Learning Experience (2013) retrieved from: https://class.ctuonline.edu/
er-optic cables. Wireless media include infrared and microwave. Traditionally, wire-based media is more popular in local area networks (LANs), while wireless media is popular in wide area networks (WANs). In newer networks, however, infrared and low-power radio media are becoming important in LANs (2013 M.U.S.E.).
The final wired media isn’t even a wire. It is called Fiber-optic and its core is made of glass or plastic. It then has a PVC sheath protecting it and then a plastic sheath on the outside. Fiber-optic is very exp