University of Kansas

Electrical Engineering & Computer Science

EECS 563 - Homework Assignment

Homework 3

1) What layer(s) perform flow control?

2) Which layer is responsible for error detection?

3) Security is only implemented at the Transport Layer. True or False

4) Network design alternatives for communications within a geographic region:

a) Suppose all computers in a geographic region communicate using radio transmissions from a one antenna tower. Is the data link layer or network layer more appropriate for communications between computers in this region, justify your answer?

b) Now suppose the geographic region is covered by a large number of small (low power) transceivers/antennas covering smaller areas; each smaller region has a base station, the base stations are interconnected by a wireless mesh network. Which layer is more appropriate, justify your answer?

c) What resources can be reused if the geographic region is covered by a large number of small (low power) transceivers/antennas each covering a smaller area and the smaller areas are interconnected by a wireless mesh network

5) Suppose an application layer entity wants to send an L-byte message to its peer process, using an existing TCP connection. The TCP segment consists of the message plus 20 bytes of header. The segment is encapsulated into an IP packet that has an additional 20 bytes of header. The IP packet in turn goes inside an Ethernet frame that has 28 bytes of header and trailer.

What percentage of the transmitted bits in the physical layer correspond to message information, if L = 10 byte and 1500 byte?

6) What is the role of IEEE in setting network standards?

7) What is an RFC?

8) Describe encapsulation?

9) The Data Link Layer packet header must include fields for what information?

10) What is the difference between flow and congestion control?



Victor S. Frost, frost@eecs.ku.edu and some problems modified from Communication Networks: Fundamentals Concepts and
Key Architectures, A. Leon-Garcia and I. Widjaja (Second edition)