CS 345 – Data Communications

Study Guide and Review Questions for Exam #1


Due:  Wednesday, March 3rd

Exam:  Friday, March 5th


DEFINITIONS: (Please define and EXPLAIN the following terms in your own words. DO NOT cut and paste from the NET)


·        De facto standards

·        De jure standards

·        Proprietary standards

·        ISO

·        ANSI

·        IEEE

·        OSI

·        TCP/IP

·        LAN

·        WAN

·        MAN

·        Encoding

·        Bit

·        Byte

·        RFC

·        Simplex

·        Half-duplex

·        Full-duplex

·        Bus

·        Star

·        Ring

·        Connectionless protocols

·        Connection-oriented protocols

·        Kilobyte

·        Megabyte

·        Analog Signal

·        Clock drift

·        Baseline Wander

·        PPM

·        PAM

·        PDM

·        PCM

·        ASK

·        PSK

·        FSK

·        QAM

·        Sampling

·        Character encoding

·        ASCII

·        EBCDIC

·        Unicode

·        RG -8 & 9

·        10Base2

·        10Base5

·        RG58





1.What are standards? Describe the three kinds of standards and give examples of each.


2.List the basic parts of a LAN.  Briefly describe the function and responsibility of each part.


3.What is the OSI model?  Why is it useful? What are the two sub-layers of the data-link layer?


4.What is TCP/IP? List the protocols within this suite’s 4 layers. How does it correspond to the OSI model?


5.Draw an Ethernet frame.


6.Identify 5 causes of analog and digital transmission errors.


7.Describe the three central network topologies and the advantages and disadvantages of each.


8.Compare and contrast connectionless transmissions to connection-oriented.


9.If I want to transmit some data from my home over a dial-up connection what device do I need?  How does it work?


10.Describe the three ways that an analog signal can be altered or modulated. Provide a diagram of each example.


11.What is a Hertz (Hz)?  A Kilohertz (KHz)?


12.What is a composite signal?


13.How do we measure digital signals?


14.What device is responsible for encoding and decoding digital signals?  What is encoding?  List the three categories of encoding schemes.


15.Be able to encode a byte using the following:

·        Unipolar

·        NRZ

·        NRZI

·        RZ

·        Manchester

·        Differential Manchester

·        4B/5B

·        AMI


16.What two problems have evolving encoding schemes tried to solve?  What causes these two problems?


17.What is sampling and why is it used?


18.What is the Nyquist theorem?


19.Which determines the bandwidth required for a transmission, bauds or bits?


20.A carrier wave between two modems can be modulated in what 4 different ways?


21What is the primary responsibility of guided and unguided media?


23.All networks can be characterized in what 3 ways?