IT 331 Week 2
IT 331 Week 2
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.
The first thing you need to do is to turn on the wireless hotspot and to search for the available Wi-Fi connections. Choose the needed one and enter the required login and password; this information acts as the encryption key that transmits traffic. Then, open the email app; once you write the text and press ‘send,’ the app uses SMTP protocol to send and deliver the data. The goal of the session layer is to add headings to the sessions: the key transport layer uses TCP, helps in encryption, divides the data into several parts, and specifies the incoming point and destination point, the network layer determines IP addresses of both points and turns the data parts into packets, and the data link layer turns the packets into frames suitable for the destination point network. Finally, the physical layer encodes the bits in a transmission medium (Network layers, n. d.).
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.
Signals are clocked with a frequency that measures the number of times the signal would complete the cycle within the given time. Data transmission may be affected by noise and adverse electromagnetic and electrical energy (White, 2015, p. 31).
According to White, self-clocking signal means that regular transition occurs with a change similar to seconds on a clock, which gives the receiver an opportunity to synchronize with the incoming bit stream (White, 2015, p. 40).
Baud Rate measures the number of signal changes (clock cycles) per second. Every clock cycle allows sending various numbers of bits; thus, the measure of bits per second becomes irrelevant.
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 sent by the computer data are encapsulated in a packet, which also contains the LAN header and trailer. During the send, they become replaced with the WAN header and trailer that give the routers the packet passes on its delivery way an opportunity to read if the packet is aimed to their network or should be passed further. The header information allows determining IP address of the destination point. After getting to the destination network, the WAN header and trailer are replaced with the LAN header and trailer once again. The sizes of the packets can be different. According to Sinha et al., they vary from 40-byte to 1500-byte (Sinha et al, 2007, p. 1). At the same time, Newman highlights that the most common size is 512-byte, but 88-byte and 1518-byte packages also have their advantages (Newman, 2006).
If the message is sent over the Internet, it will definitely go through at least one router. The primary goal of routers is the connection between different networks due to the technology of a routing table, and without a router, the packet cannot leave the original network and to be delivered.
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)?
Frequency means the number of times the signal would complete the cycle within the given time. We need to find the frequency in cycles per second, thus the frequency is: 60.000/60sec=1000 Hz. (1000 Hz per sec).
The period is: 1/1000 Hz = 0.001 sec = 100 ms (milliseconds). The period means the length of one cycle.
What is the bandwidth of a signal composed of frequencies from 60 Hz to 600 Hz?
The bandwidth of a signal is equal to the difference of frequencies: 600 Hz – 60 Hz = 540 Hz
References
Network layers. (n. d.). Retrieved from https://www.d.umn.edu/~gshute/net/layers.xhtml.
Newman, D. (2006, Nov 6). Picking the ‘best’ packet size. Network World. Retrieved from http://www.networkworld.com/article/2300175/network-security/picking-the--best--packet-size.html.
Sinha, R., Papadopoulos, C., & Heidemann, J. (2007). Internet package size distributions: some observations. Retrieved from https://www.isi.edu/~johnh/PAPERS/Sinha07a.pdf.
White, C. (2015). Data Communications and Computer Networks: A Business User’s Approach. Boston, MA: Cengage Learning.
