COSC 450: Computer Networks
Homework Assignment #1
Due: 1/29/2009
- Give three advantages of using a layered architecture (instead of
a monolithic architecture) as a model for networking. What are the
advantages of having more layers as opposed to fewer layers? What are
the disadvantages? Why does the TCP/IP model have fewer layers that
the OSI model?
- What was the exact number of hosts on the Internet on January 1st,
2009 at midnight? What authority would have this information?
- Between cable, DSL, and FIOS services, which Internet provider has
the best download speed/cost ratio? Compare the speeds and prices for
the offerings in Pittsburgh (if available) of Comcast Cable, Verizon
DSL for the home, and Verizon FIOS for the home. Choose the best
speed/cost plan for each provider, and use the actual, not the
introductory price. Look at the costs just for Internet service, i.e.,
not bundled with phone or cable service. Give the best speed/price
ratios for each Internet provider.
- Do Questions 2-5 of Practice Set 3.7 of the book.
- The IP address of server3.mathcs.duq.edu is 165.190.114.169. What
class of network is this? What is the netid? What is the hostid? What
is the (default) netmask? How many computers can be on the same
network?
- Do Question 10 of Practice Set 5.6 of the book.
- Bonus Trivia Question: Class A networks are now referred to as /8
blocks (as the default netmask has eight bits set to 1). Give the name
of an organization that has a /7 block of IP addresses.
Last modified: Jan. 21, 2009
Dr. Donald L. Simon,
simon@mathcs.duq.edu