HOMEWORK 1
Assigned: Sept.14,
1999
Due: Sept 28, 1999 (before class)
All questions can be answered if you
closely read the book, review notes, and follow assigned links. If you
deem it is necessary to support your arguments by citing other sources, please
do. Make sure, however, that you list your source.
Note: Please hand in printed
versions of the homework assignment on the due date.
1.
The word "OCT" is to be transmitted using asynchronous
transmission. Characters are to be represented in an 8-bit format starting with
7-bit ASCII representation of the character with least significant bit first,
and followed by a parity bit. Even parity is used.0 is the start bit and 1 is
the end bit. In other words, ASCII character “v” would be represented as:
0011011111. Refer to Chapter 5 in your book for more information and then answer
the following questions:
a.
What is the sequence of bits that will be used to transmit the word
"OCT"?
Clearly label start bits, end bits, and parity bits. Remember that words
are usually transmitted as sequences of characters. (2)
b.
What is the overhead of signaling and error detection bits in percent per
each character transmitted?(2)
c.
Bearing previous answer in mind, why is it recommended that synchronous
transmission (e.g. HDLC) be used for larger data transfers?(2)
2. Name the common
techniques on which error control is based on and explain how they are
actually implemented.
- Identification of
techniques (2)
- Explanation of implementation.(ARQ) (8)
3. a. How do SMTP, IMAP
and POP fit into the e-mail system of an organization (use outside sources
if necessary)?
- Identification of
roles of the 3 protocols (3)
- Difference between
IMAP & POP (2)
b.
How does 100BASE-T4 differ from traditional Ethernet. Explain.
- Difference (2)
- Explanation (3)
4. Workstations
W1 and W2 are nodes on the same 100Base-T LAN utilizing CSMA/CD.Each workstation
is a part of a different collision domain. If both workstations start
transmitting data at the same time will a collision occur? Why or why not?(4)
5. In class we discussed different types of servers.
List all types, describe their functions, and find a vendor that produces
it. (5)
6. Case Study : http://amp.com/networking/case-studies/cobb.asp
Enumerate all the
technologies/strategies mentioned and describe how they proved to be advantageous
to the district.
(10)
(Hint : I expect some form of a table enumerating the technology/strategy and
the specific benefit(s))
7. Visit http://www.citrix.com
and take a look at their WinFrame product.
- Explain what
is server-based computing? (5)
- What are some of the benefits of
the product as listed in the site? Explain their significance in an
organizational setting. (5)
- What are some of the concerns you
might have about this product? (5)
(20)
8. You have
just started your career as an IT consultant for iConsultant Inc. Your first
client, a major stock exchange, is asking your firm to implement a wireless LAN
in their new building in downtown New York City.
The company has very mobile workforce and is hoping to add flexibility to
traders on the trading floor, as well as the staff supporting the operations of
traders.
You have been asked to give
expert opinion on this project because the partner who hired you knows that you
graduated from Carnegie Mellon University, the home of “Wireless Andrew”.
The partner has heard that “Wireless Andrew”, project that
implemented a wireless LAN across the CMU campus, has been a great success and
wants to hear your first hand experience.
To
begin with, the partner needs to provide the client with an overview of
“Wireless Andrew” and technologies that it involved.
She does not feel comfortable in doing that, so she asks you to help her
out. She has read a couple of
papers on “Wireless Andrew”, but she feels you could shed some light on the
terminology used. You agree readily
even though you have no clear idea of what “Wireless Andrew” is all about.
“This could mean a great start and iConsultant Inc. and a hefty bonus
at the end of the year!” you say to yourself.
The
partner provides you with a sheet with several questions:
1.
a.
What is CDPD?
b.
What is the range (coverage radius) of CDPD technology?
c.
When is CDPD used in “Wireless Andrew” (locality)?
d.
What is CDPD’s maximum theoretical speed (raw transmission data
bandwidth)?
e.
What is its typical “throughput” i.e. its effective speed?
f.
How does that speed compare to standard modem speeds available today?
2.
a.
What is WaveLAN?
b.
What is its theoretical range? What kind of objects can significantly
reduce WaveLAN’s range?
c.
What is it’s range (coverage radius)?
d.
What is WaveLAN’s maximum theoretical speed (raw transmission data
bandwidth)?
e.
What is its typical “throughput” i.e. its effective speed?
f.
How does that speed compare to 10BASE-T speeds?
g.
What are the frequencies at which WaveLAN operates?
Why?
3.
How do CDPD and WaveLAN fit together in the “Wireless Andrew” picture
i.e. which is used when?
4.
Describe the OSI model. Name
every layer and briefly describe its functions. On which layer(s) does CDPD
operate?
5.
What is “roaming” in the context of “Wireless Andrew”?
6.
What is a peer-to-peer network? Can
users of “Wireless Andrew” set-up peer-to-peer networks?
Luckily, an
analyst working under you did some very good research and has located almost all
material you need to answer the questions.
Here is the list of what he discovered:
·
Wireless Data Network Infrastructure at Carnegie Mellon University [ http://www.monarch.cs.cmu.edu/monarch-papers/pcs-andrew.ps
] - A paper written in 1996 that talks about “Wireless Andrew” in detail.
The analyst thinks this might be one of your best sources.
·
Case Study in Wireless LAN Technology [ http://www.dma.org/~moulderpa/case-s.htm
] - A case study on “Wireless Andrew”. Great source of information and
definitions. Many concepts
explained in the first paper are defined very crisply in this case study.
·
Book Business Data Communications, 3rd Edition – Description
of the OSI model and other network concepts.
·
Introduction to Wireless LANs [http://www.wlana.com/intro/introduction/index.html
] – Additional information on wireless LAN technology.
The partner expects your work to be professional, on the level of the prestige
for iConsultant Inc. You are
assured that good work will be rewarded nicely.
