Connecting to a Network
While a computer on its own is a great tool, some of its greatest potential lies in the ability to network computers together. A network, simply stated, is a set of nodes (computers, routers, wireless access points, etc.) that are interconnected by communication paths (Ethernet, fiber, coax, wireless, etc.). Networks can communicate with other networks and contain sub-networks. Networks can be categorized many ways either by topology, geographical location, communication method, data type, and other various means. We will discuss these categorizations in greater detail later in the course.
Wireless Network Access
There are two primary ways in which your computer can connect to a network at NC State; either via an Ethernet cable that is plugged into a jack or wirelessly. With the advent of wireless computer communication and the IEEE (Institute of Electrical and Electronics Engineers) 802.11 group of standards, networking computers has become even easier. The 802.11 standard specifies an over-the-air interface between a wireless client and a base station or between two wireless clients.
There are several specifications in the 802.11 family: *
| Standard | Data Rate ** | Band ** | Range (Approx.) *** |
|---|---|---|---|
| 802.11 | 2 Mbit/s | 2.4 GHz | N/A |
| 802.11a | 54 Mbit/s | 5 GHz | 25 m |
| 802.11b | 11 Mbit/s | 2.4 GHz | 35 m |
| 802.11g | 20 Mbit/s | 2.4 GHz | 25 m |
| 802.11n * | 200 Mbit/s | 2.4 GHz or 5 GHz | 50 m |
*802.11n has just gone through its second draft, and has not yet been ratified as an official standard for wireless.
**All data given is listed in its minimum form; i.e. there are certain circumstances that would allow these wireless standards to have higher data rates and ranges, but we will not be considering these for the scope of this class.
***All ranges are based upon indoor estimations.
Important Network Pointers
The important thing to note about networks is that when two computers are networked with one another they are in constant contact. This means that what one computer does can have an effect on the other computer. Now let’s take this to a much larger scale. Let’s say that we have 100 computers all connected together. All of these computers have an effect on the other computers based on what and how they can communicate. While this networking can be very powerful it can also be very dangerous to the computer(s) involved. If a virus infects one computer on the network it stands a good chance to infect the others. If a malicious user gains access to one machine on the network, that user is now more likely to gain access to other machines on the network.
As you can see, many bad things can happen when computers are connected together. When you are connected to a network you are putting your computer out there for attack. That’s why it is your responsibility as the user of your computer to make sure that it is secured against possible threats.
