# It 321 Final Exam Study Guide

Topics: Ethernet, MAC address, Modulation Pages: 7 (1270 words) Published: February 6, 2013
IT321 Final Exam Review Guide

A review guide is just that, a guide. It is not a blueprint of what you will be tested on. This guide will consist of key points that have a very high probability of being on the quiz/test/exam that you will see. I feel review guides are important because students new to the topic may waste time and study the wrong materials. This normally leads to frustration and concepts not covered that are deemed important in not only passing this course, but what would/could be asked of the student in a real world situation.

1. How many channels can a DS-3 circuit carry?

Twenty-eight 1,544 Mbps time slots

2. What are the common rates used in both the North American Hierarchy and SONET? (Please research three.)
DS-0
DS-1
DS-3

3. What is the purpose of the North American Hierarchy? (two reasons)
To define the circuit bit-per-second rate (standard transmission rate) A standard for the amount of information a digital circuit can carry
4. How long will it take for a two-mega-bit file to transmit across a DS-0 circuit?
Roughly 32 seconds

5. When is a block check character used?

When you want to check for errors in a block of data

6. The capacity of T-1 circuits can be sub-divided into how many bits per second?
64,000 bps

7. (T or F) Full duplex transmission can occur on a two-wire circuit.
True

8. (T or F) Distortion on a digital circuit is easier to correct than on an analog circuit.
True

9. (T or F) A T-3 circuit has the same capacity as three T-1 circuits.
False

10. (T or F) A punchdown block can be used as a security device by blocking the signals on a pair of wires.
False

11. (T or F) A concentrator combines several low-speed circuits onto one high-speed circuit.
True

12. What is the most common medium used for telecommunications circuits?
A wire

13. (T or F) SONET is a standard for transmitting data on optical fibers.
False

14. When a Network Address Translation (NAT) router receives an incoming message, what information in the message is used to determine the final host destination?

15. What routing protocol is used to manage Internet routing based on both number of hops and link weights?
On-demand distance vector routing protocol (AODV) – Quality of Service routing protocol (QoS)
16. Why is fiber-optic cable a good choice when security is a consideration in choosing the medium?
It is less vulnerable to signal interference and eavesdropping
17. What is the primary limitation of microwave transmission?
The transmitter and receiver must be in a direct line of sight with each other
18. What is being used when a message is multiplexed and sent with extra bits for a terminal address in a random time slot?
Statistical Time Division Multiplexing (STDM)

19. What is the property of electrical signals that causes them to weaken over a distance called?
Attenuation

20. What analog modulation method allows for the greatest number of data bits per baud during data transmission?
Phase modulation

21. (T or F) Point-to-point protocol (PPP) is primarily used by PC workstations to dial in to a TCP/IP-based network.
False

22. (T or F) An Ethernet switch can determine whether to forward or drop a packet depending on the packets destination MAC address.
True

23. What is the way circuits are connected together to form a network called?Topology

24. The media access control (MAC) address is defined at what layer of the open system interconnect (OSI) model?

25. (T or F) The access method used on an Ethernet network can allow collisions to occur during data transmission.
True

26. What is a defining characteristic of a ring topology network?
It has no master station

27. What is the term that describes the unevenness of packet delays within a packet stream?
Jitter

28 What is the term that is...