Week 26 Module

The Objectives for the lesson will be as follows:

1) Identify the components of a wide area network.

2) Compare methods that corporations use to connect to the point of presence. 

3) Compare and contrast packet switching networks and circuit switching networks.

4) Describe 3 types of WANs.

A wide area network  connects computers together in a large geographical area.  WANs are ideal network when there are many offices located in many locations in the same city. They can also connect offices in different cities or even states. In some cases, WANs are used globally, as in the case of multinational corporations. Much like a local area network, the purpose of a WAN is to share files and information.  A local area network is group of computers that are connected together in an office. Wide area networks, on the other hand,  are often employed by large organizations.  A WAN consists of many local area networks (offices) in different cities or states that are connected together through a backbone, a fast internet connection. A point of presence is usually a server or router  that connects  the local area networks (offices) in the WAN to the internet. "Users gain access to the information on the network with proper permissions (Wexiel, 2017).

A WAN is managed through a network operating system. The purpose of the network operating system is to help manage the traffic of the network and its resources.  

One of the first steps in creating a WAN is determining what internet connections to use. There are digital subscriber lines, leased lines, T1 lines, and permanent virtual circuits.  WANs that use DSL lines use regular telephone lines (Wexiel, 2017).  Since computers only communicate in 0's and 1's, a modem has to convert the information to analog signals, so that they can travel through the telephone lines. Once the message reaches its destination, the signal is converted back to digital through the receiver's modem. This process is called demodulation.  This process allows the computer to process the information into text, video, or images. 

When an organization leases a line, it rents a line from a telecommunications company to create its wide area network.  The lease line becomes a dedicated line with the sole purpose of connecting different locations together. No other users, for example, can use the lease line other than the company.  

"T1 lines can be copper or fiber optic" (Weixel, 2017).  "They  allow data to be sent at more than 1.5 million bps"(Wexiel, 2017). 

There are several types of wide area networks.  They are public data networks, private data networks, virtual private networks, and  metropolitan area networks. 

An example of a public data network would be the World Wide Web. Public data networks are accessible by anyone. 

A private data network only allows certain users access to a company's network (Wexiel, 2017). Many corporations, for example, restrict access to their servers to only employees of an organization. They do this by requiring their employees to login using their user ids and passwords.  An example of an organization that uses this type of network could be a governmental agency, like the Social Security Administration. Only employees, in this example, would have  access to information on the agency's server. Radio Shack would be another example of a company restricting access to its employee portal, where profit margins and whole-sale prices of inventory are listed. 

A virtual private network, is a "private network that is set up through a public network" (Wexiel, 2017) Information sent through this network is encrypted and cannot be intercepted or viewed as it travels to its destination.  

When public networks are used, however, the information sent through the internet can be seen or intercepted as it makes its way to its destination.

 A metropolitan area network is not as extensive as a wide area network. It is often used when a company has different offices in a single city (Wexiel, 2017).  

So, how is information sent over long distances? Files are broken down into small packets. Each packet has the address of the computer that the file is being sent to.  The small packets then travel through the telephone lines or radio waves to their destination. Once they reach their destination or receiving computer, the small packets are reassembled into files. This is how files are transferred over the internet. 

References: Weixel, S. (2017). Principles of Information Technology: Preparing for IC³ certification. Pearson.