Today with so many different models and brands of home routers it is difficult for many reading this course to appreciate that there is more to configuring a network device than putting a SSID (which is the name of the wireless network) and a WPA2 security code into a wireless router.
Professionally, Network Engineers who manage the networks for your school, university or workplace do a considerably more complex task with an extensive range of networking devices.
What many also discover is that networking is a world of jargon, you read an earlier paragraph and may already wondered what SSID and WPA2 meant. We will explain these soon.
Figure 1: A Network Engineer installing a router.
To become a Network Engineer, you will discover on your journey that many technologies interact. As you get your head around ‘how one works’ you will discover that there are other complex technologies that all equally interact with each other. Don’t let this put you off, in fact the greatest part of the fascination in networking is that there is often something new to learn no matter how expert you become. As different technologies are being developed all of the time.
So back to the jargon, SSID stands for ‘service set identifier’, quite a dull term, but when you are in your favourite cafe, the chances are when you are using the free WiFi, your mobile device (or this tablet) is looking for an SSID which contains the name of the WiFi network.
Figure 2: A list of wireless network SSIDs.
In Figure 2, you can see the SSID of the laptop belonging to someone who helped create this course, you can also see if you look carefully that they have a sense of humour when creating one of the SSID’s for their home network.
WPA2, is short for WiFi Protected Access (version 2), a method of security used on Wireless Networks around the world. You may have been asked for a WPA2 key (a key is a type of password) by your wireless router. There are more secure protocols, you can learn more from an equally useful guide from the BBC.
On completing this chapter you should understand the following:
When it comes to introducing large networks, space is limited on some screens such as an iPad. Some commercial systems, especially those offered by your internet service provider will have 100’s of devices. Too many for the visual space available. What you will see and become familiar with this course is a simulated network using PT Anywhere.
PT Anywhere offers a network simulation environment via a web interface that can be accessed from any web browser or as a widget inside an interactive eBook. PT Anywhere is based on the Packet Tracer network simulator for Windows and Linux developed by the Cisco Networking Academy.
As a simulator, Packet Tracer allows you to ‘pretend’ that you are configuring a real networking device. There is always an argument about how real is real when it comes to simulation, commercial flight simulators are not real, but civil aviation pilots are still expected to practice in them.
Like a flight simulator, Packet Tracer allows you to complete tasks and gain experiences that you would never be allowed to try out on a live system. Passengers tend to become quite emotional if the pilot decides that it's time to practice their barrel roll skills during take off. Network users tend to have similar feelings when the network engineer starts fiddling around with the system when we are all trying to download online movies.
Packet Tracer pretends to be different types of network servers, routers, switches, cables and workstations. We shall now introduce each of these and explore their purpose. In this course, you will be able to access Packet Tracer via the PT-Anywhere widget, giving you access to a remote instance of Packet Tracer.
Later in this course, you will be able to configure the simple network via PT-Anywhere, shown in Figure 3. You will discover that the cloud icon on the left hand side, will hide multiple routers a switch and some servers. You will be able to configure one router, one switch and two workstations (or personal computers).
Figure 3: A Packet Tracer network consisting of two PC’s one switch, router and cloud.
Clouds are funny things, over the last few years a common misconception is that the world of technology has become totally cloud based. For SciFi fans, clouds tend to hold cities in Star Wars or Flash Gordon as well as rain, hail and snow for the rest of us.
Cloud icons have been used for a very long time to represent large networks. Normally as a way of saying “there is something out there, but you cannot see it from here”. Behind this cloud icon, we have hidden some network technology. This may be on a remote server or locked away inside this course.
Figure 4: Representation of a network server in Packet Tracer.
Learning about servers are an entire course in their own right; as are each of the other technologies in this section. We will give you a very brief introduction, to help you understand a little more about your simulator and network technology.
The google definition of server is “a computer or computer program which manages access to a centralised resource or service in a network”. For the purposes of this course, we will agree with this description, but you will discover Network Engineers and geeks that will tell you that there is much more to this technology.
Often servers have been used to help us with email or the storing of files. Somewhere on the internet, there are servers holding copies of this course that you downloaded. In reality every time you visit a web page, a web site or use a social media service. You are interacting remotely with a server.
We also use servers for to support the many services that keep our networks running. Domain Name Services (or DNS) is used to link the names of web sites to the IP (internet protocol) addresses of these servers. Don’t panic, during the practical activity later in this course we will give you a little bit more information on IP addresses.
If you look at Figure 5, you can see some of the protocols used in Packet Tracer. Why not use a search engine to discover what FTP, TFTP, DHCP, NTP and HTTP all do.
Servers come in different shapes and sizes, as you can see in the server room demonstration of Movie 1. In this video, Andrew Smith from the Faculty of Mathematics, Computing and Technology of the Open University and Ben Hawkridge from the Knowledge Media Institute of the Open University show the equipment typically found in a server room and discuss its usage.