Solution manual
Data Communications And Networking
With Tcp|Ip Protocol Suite
By Behrouz Forouzan
6th edition
about:blank 1/327
, Chapter 1
Introduction
Solutions to review questions and exercises
Review questions
1. The five components of a data communication
system are the sender, receiver,
Transmission medium, message, and protocol.
2. The advantages of distributed processing are
security, access to distributed data- bases,
collaborative processing, and faster problem
solving.
3. The three criteria are performance, reliability,
and security.
4. Advantages of a multipoint over a point-to-point
configuration (type of connec- tion) include ease
of installation and low cost.
5. Line configurations (or types of connections) are
point-to-point and multipoint.
6. We can divide line configuration in two broad
categories:
a. Point-to-point: mesh, star, and ring.
b. Multipoint: bus
7. In half-duplex transmission, only one entity
can send at a time; in a full-duplex
transmission, both entities can send at the same
time.
8. We give an advantage for each of four network
topologies:
a. Mesh: secure
b. Bus: easy installation
c. Star: robust
about:blank 2/327
, d. Ring: easy fault isolation
9. The number of cables for each type of network is:
a. Mesh: n (n – 1) / 2
b. Star: n
c. Ring: n – 1
d. Bus: one backbone and n drop lines
10. The general factors are size, distances (covered
by the network), structure, and
Ownership.
11. An internet is an interconnection of networks.
The internet is the name of a spe- cific
worldwide network
12. A protocol defines what is communicated, in
what way and when. This provides accurate and
timely transfer of information between different
devices on a net- work.
13. Standards are needed to create and maintain an
open and competitive market for manufacturers,
to coordinate protocol rules, and thus guarantee
compatibility of data communication
technologies.
Exercises
14. Unicode uses 32 bits to represent a symbol or a
character. We can define 232 differ- ent symbols
or characters.
15. With 16 bits, we can represent
up to 216 different colors. 16.
a. Cable links: n (n – 1) / 2 = (6 × 5) / 2 = 15
b. Number of ports: (n – 1) = 5 ports needed per
device
17.
about:blank 3/327
, Mesh topology: if one connection fails, the
a.
other connections will still be work- ing.
b. Star topology: the other devices will still be
able to send data through the hub; there will be
no access to the device which has the failed
connection to the hub.
c. Bus topology: all transmission stops if the
failure is in the bus. If the drop-line fails, only
the corresponding device cannot operate.
d. Ring topology: the failed connection may
disable the whole network unless it is a dual
ring or there is a by-pass mechanism.
18. This is a lan. The ethernet hub creates a lan as we
will see in chapter 13.
19. Theoretically, in a ring topology, unplugging
one station, interrupts the ring. How- ever, most
ring networks use a mechanism that bypasses the
station; the ring can continue its operation.
20. In a bus topology, no station is in the path of the
signal. Unplugging a station has no effect on the
operation of the rest of the network.
21. See figure 1.1
22. See figure 1.2.
23.
E-mail is not an interactive application. Even if
a.
it is delivered immediately, it may stay in the
mail-box of the receiver for a while. It is not
sensitive to delay.
b. We normally do not expect a file to be copied
immediately. It is not very sensi- tive to delay.
c. Surfing the internet is the an application very
sensitive to delay. We except to get access to
the site we are searching.
24. In this case, the communication is only between a
caller and the callee. A dedi- cated line is
about:blank 4/327
Data Communications And Networking
With Tcp|Ip Protocol Suite
By Behrouz Forouzan
6th edition
about:blank 1/327
, Chapter 1
Introduction
Solutions to review questions and exercises
Review questions
1. The five components of a data communication
system are the sender, receiver,
Transmission medium, message, and protocol.
2. The advantages of distributed processing are
security, access to distributed data- bases,
collaborative processing, and faster problem
solving.
3. The three criteria are performance, reliability,
and security.
4. Advantages of a multipoint over a point-to-point
configuration (type of connec- tion) include ease
of installation and low cost.
5. Line configurations (or types of connections) are
point-to-point and multipoint.
6. We can divide line configuration in two broad
categories:
a. Point-to-point: mesh, star, and ring.
b. Multipoint: bus
7. In half-duplex transmission, only one entity
can send at a time; in a full-duplex
transmission, both entities can send at the same
time.
8. We give an advantage for each of four network
topologies:
a. Mesh: secure
b. Bus: easy installation
c. Star: robust
about:blank 2/327
, d. Ring: easy fault isolation
9. The number of cables for each type of network is:
a. Mesh: n (n – 1) / 2
b. Star: n
c. Ring: n – 1
d. Bus: one backbone and n drop lines
10. The general factors are size, distances (covered
by the network), structure, and
Ownership.
11. An internet is an interconnection of networks.
The internet is the name of a spe- cific
worldwide network
12. A protocol defines what is communicated, in
what way and when. This provides accurate and
timely transfer of information between different
devices on a net- work.
13. Standards are needed to create and maintain an
open and competitive market for manufacturers,
to coordinate protocol rules, and thus guarantee
compatibility of data communication
technologies.
Exercises
14. Unicode uses 32 bits to represent a symbol or a
character. We can define 232 differ- ent symbols
or characters.
15. With 16 bits, we can represent
up to 216 different colors. 16.
a. Cable links: n (n – 1) / 2 = (6 × 5) / 2 = 15
b. Number of ports: (n – 1) = 5 ports needed per
device
17.
about:blank 3/327
, Mesh topology: if one connection fails, the
a.
other connections will still be work- ing.
b. Star topology: the other devices will still be
able to send data through the hub; there will be
no access to the device which has the failed
connection to the hub.
c. Bus topology: all transmission stops if the
failure is in the bus. If the drop-line fails, only
the corresponding device cannot operate.
d. Ring topology: the failed connection may
disable the whole network unless it is a dual
ring or there is a by-pass mechanism.
18. This is a lan. The ethernet hub creates a lan as we
will see in chapter 13.
19. Theoretically, in a ring topology, unplugging
one station, interrupts the ring. How- ever, most
ring networks use a mechanism that bypasses the
station; the ring can continue its operation.
20. In a bus topology, no station is in the path of the
signal. Unplugging a station has no effect on the
operation of the rest of the network.
21. See figure 1.1
22. See figure 1.2.
23.
E-mail is not an interactive application. Even if
a.
it is delivered immediately, it may stay in the
mail-box of the receiver for a while. It is not
sensitive to delay.
b. We normally do not expect a file to be copied
immediately. It is not very sensi- tive to delay.
c. Surfing the internet is the an application very
sensitive to delay. We except to get access to
the site we are searching.
24. In this case, the communication is only between a
caller and the callee. A dedi- cated line is
about:blank 4/327
