Running head: UNIT 2 ASSIGNMENT 1

Unit 2 Assignment

[ Student Name ]

Kaplan University

1. Describe the series of connections that would be made, equipment and protocol changes, if you connected your laptop to a wireless hotspot and opened your email program and sent an email to someone. Think of all the layers and the round trip the information will likely make.

When you connect to a wireless hotspot, the data will be transmitted over the air through the physical layer of the OSI model. This layer also determines the technique that will be used for encoding and modulation on the network. Most likely, the architecture that is being used for the network is the TCP/IP protocol, since it is the most commonly used. The application layer is responsible for supporting the software that runs the network (White, n.d.).

When you send an email, the presentation layer of the OSI model may be used, if you are sending encrypted emails or for ASCII to non-ASCII character conversions. The session layer is primarily responsible for establishing sessions between the server and various computers. It is also responsible for establishing backup points which are used to prevent data from being lost. The transport layer ensures that the packets that are being sent are the same as the ones being received by the final destination (White, n.d.).

The network layer will help transport the data packets from one router to another, while the data link layer takes information that is on the network layer and converts it into a frame. All of these layers play an important part in the transfer of data between devices, including the ability to send emails from one person to another (White, n.d.).

1. How are signals clocked and how does that affect data transmission? What does it mean when a signal is self-clocking? How does baud rate differ from bits per second? Explain the relationship between frequency and Baud Rate_._

Digital data can be transmitted using square wave digital signals. These signals have to first be converted to a proper physical form that can be transmitted. In order to do this, a positive or 0 voltage can be transmitted on the medium. Signal clocking is a way for the signal receiver to determine when one signal bit ends and the next signal bit begins. The signal receiver attempts to synchronize its own reading of the data with the real data pattern that is being transmitted by looking for changes in the signal (White, n.d.).

When a signal is self-clocking it means that a Manchester encoding scheme has a signal transition that is timed almost exactly the same as the seconds on a clock. The baud rate is the number of times that a signal changes value per second, whereas bits per second is simply the number of bits transmitted per second. The relationship between baud rate and frequency is that they are both methods of determining how often a signal changes in one second (White, n.d.).

1. The addition of control information to a packet as it moves through the layers is called encapsulation. Provide a brief overview of the process as requested pieces of data (packets) undergoes as it is sent over the Internet. What are the sizes of the packets? What is the likelihood that a message sent over the Internet will go through at least 1 router. Why?

The encapsulation process starts with layer 7 of the OSI model and ends with layer 1.

Packets are basically small pieces of information that, all together, make up one or more files. The encapsulation process uses packets called Protocol Data Units (PDUs) which are passed from one layer to another in the OSI model. These packets contain information regarding each layer of the OSI model. When the PDU passes from one layer to another, each layer adds information to the packet by adding a header to it (CCI Learning Solutions, n.d.).

This information allows each of the layers to communicate with each other. Information that is passed down to a layer from a higher layer in the OSI model is called a data payload.

Once the entire process is completed, a frame is created. The sizes of data packets can vary since different amounts of data are sent at different times. A lot of this will have to do with the type of connection being used. The likelihood of a message going through at least 1 router is pretty high because a lot of users and organizations use Wi-Fi technology to access the internet. This Wi-Fi technology relies on routers to provide a wireless access point for the internet (CCI Learning

Solutions, n.d.).

4 . Provide the results of these calculations • What is the frequency, in Hertz, of a signal that repeats 60,000 times within one minute? What is its period (the length of one complete cycle)? • What is the bandwidth of a signal composed of frequencies from 60 Hz to 600 Hz? Frequency in hertz = 1,000 Hz

Period = 1/1000 = .001

Bandwidth = 600 – 60 = 540 Hz

References

White, C. M. (2016). Data communications and computer networks: A business user’s approach.

(8^th, Ed.). Retrieved from https://kaplan.vitalsource.com/#/ books/ 9781305465244 /cfi/0

CCI Learning Solutions. (n.d.). The data encapsulation process. Retrieved from http://strata.ccilearning.com/Lesson3NetworkingandInternetworking/TheDataEncapsulati onProcess/tabid/733/language/en-CA/Default.aspx