Data and Computer Communications –
ST
10th Edition
SOLUTIONS
UV
MANUAL
IA
_A
William Stallings
PP
RO
Comprehensive Solutions Manual for
Instructors and Students
VE
D?
© William Stallings
All rights reserved. Reproduction or distribution without permission is prohibited.
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©STUDYSTREAM
, TABLE OF CONTENTS
ST
Chapter 2 Protocol Architecture .................................................. 5
Chapter 3 Data Transmission ................................................... 10
Chapter 4 Transmission Media ................................................. 15
UV
Chapter 5 Signal Encoding Techniques ...................................... 20
Chapter 6 Error Detection and Correction .................................. 30
Chapter 7 Data Link Control Protocols ....................................... 37
Chapter 8 Multiplexing ............................................................ 45
Chapter 9 WAN Technology and Protocols.................................. 52
IA
Chapter 10 Cellular Wireless Networks ...................................... 63
Chapter 11 Local Area Network Overview .................................. 67
Chapter 12 Ethernet ............................................................... 75
Chapter 13 Wireless LANs ....................................................... 81
_A
PP
RO
VE
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-4-
, CHAPTER 2 PROTOCOL ARCHITECTURE
ST
ANSWERS TO QUESTIONS
UV
2.1 The network access layer is concerned with the exchange of data
between a computer and the network to which it is attached.
2.2 The transport layer is concerned with data reliability and correct
IA
sequencing.
2.3 A protocol is the set of rules or conventions governing the way in which
_A
two entities cooperate to exchange data.
2.4 A PDU is the combination of data from the next higher communications
layer and control information.
PP
2.5 The software structure that implements the communications function.
Typically, the protocol architecture consists of a layered set of protocols,
with one or more protocols at each layer.
2.6 Transmission Control Protocol/Internet Protocol (TCP/IP) are two
RO
protocols originally designed to provide low level support for
internetworking. The term is also used generically to refer to a more
comprehensive collection of protocols developed by the U.S.
Department of Defense and the Internet community.
VE
2.7 Layering decomposes the overall communications problem into a
number of more manageable subproblems.
2.8 A router is a device that operates at the Network layer of the OSI model
to connect dissimilar networks.
D?
2.9 IPv4.
2.10 No, other transport layer protocols, such as UDP, are also used. Some
traffic uses no transport protocol, such as ICMP.
??
2.11 IPv4 - 32 bits; IPv6 - 128 bits
-5-
, ANSWERS TO PROBLEMS
2.1 The guest effectively places the order with the cook. The host
ST
communicates this order to the clerk, who places the order with the
cook. The phone system provides the physical means for the order to be
transported from host to clerk. The cook gives the pizza to the clerk
with the order form (acting as a "header" to the pizza). The clerk boxes
the pizza with the delivery address, and the delivery van encloses all of
UV
the orders to be delivered. The road provides the physical path for
delivery.
2.2 a.
French PM Chinese PM
IA
Translator (F → E) Translator (E → C)
Telephone Telephone
Telephone line
_A
The PMs speak as if they are speaking directly to each other. For
example, when the French PM speaks, he addresses his remarks directly
to the Chinese PM. However, the message is actually passed through
two translators via the phone system. The French PM's translator
PP
translates his remarks into English and telephones these to the Chinese
PM's translator, who translates these remarks into Chinese.
b.
French PM Chinese PM
RO
Tr (F → G) Tr (G → J) Tr (J → C)
Phone Phone Phone Phone
Telephone line
VE
An intermediate node serves to translate the message before passing it
on. Note that the intermediate node handles the message only up to the
second level; a minister's level is not needed.
2.3 Perhaps the major disadvantage is the processing and data overhead.
D?
There is processing overhead because as many as seven modules (OSI
model) are invoked to move data from the application through the
communications software. There is data overhead because of the
appending of multiple headers to the data. Another possible
disadvantage is that there must be at least one protocol standard per
??
layer. With so many layers, it takes a long time to develop and
promulgate the standards.
-6-
ST
10th Edition
SOLUTIONS
UV
MANUAL
IA
_A
William Stallings
PP
RO
Comprehensive Solutions Manual for
Instructors and Students
VE
D?
© William Stallings
All rights reserved. Reproduction or distribution without permission is prohibited.
??
©STUDYSTREAM
, TABLE OF CONTENTS
ST
Chapter 2 Protocol Architecture .................................................. 5
Chapter 3 Data Transmission ................................................... 10
Chapter 4 Transmission Media ................................................. 15
UV
Chapter 5 Signal Encoding Techniques ...................................... 20
Chapter 6 Error Detection and Correction .................................. 30
Chapter 7 Data Link Control Protocols ....................................... 37
Chapter 8 Multiplexing ............................................................ 45
Chapter 9 WAN Technology and Protocols.................................. 52
IA
Chapter 10 Cellular Wireless Networks ...................................... 63
Chapter 11 Local Area Network Overview .................................. 67
Chapter 12 Ethernet ............................................................... 75
Chapter 13 Wireless LANs ....................................................... 81
_A
PP
RO
VE
D?
??
-4-
, CHAPTER 2 PROTOCOL ARCHITECTURE
ST
ANSWERS TO QUESTIONS
UV
2.1 The network access layer is concerned with the exchange of data
between a computer and the network to which it is attached.
2.2 The transport layer is concerned with data reliability and correct
IA
sequencing.
2.3 A protocol is the set of rules or conventions governing the way in which
_A
two entities cooperate to exchange data.
2.4 A PDU is the combination of data from the next higher communications
layer and control information.
PP
2.5 The software structure that implements the communications function.
Typically, the protocol architecture consists of a layered set of protocols,
with one or more protocols at each layer.
2.6 Transmission Control Protocol/Internet Protocol (TCP/IP) are two
RO
protocols originally designed to provide low level support for
internetworking. The term is also used generically to refer to a more
comprehensive collection of protocols developed by the U.S.
Department of Defense and the Internet community.
VE
2.7 Layering decomposes the overall communications problem into a
number of more manageable subproblems.
2.8 A router is a device that operates at the Network layer of the OSI model
to connect dissimilar networks.
D?
2.9 IPv4.
2.10 No, other transport layer protocols, such as UDP, are also used. Some
traffic uses no transport protocol, such as ICMP.
??
2.11 IPv4 - 32 bits; IPv6 - 128 bits
-5-
, ANSWERS TO PROBLEMS
2.1 The guest effectively places the order with the cook. The host
ST
communicates this order to the clerk, who places the order with the
cook. The phone system provides the physical means for the order to be
transported from host to clerk. The cook gives the pizza to the clerk
with the order form (acting as a "header" to the pizza). The clerk boxes
the pizza with the delivery address, and the delivery van encloses all of
UV
the orders to be delivered. The road provides the physical path for
delivery.
2.2 a.
French PM Chinese PM
IA
Translator (F → E) Translator (E → C)
Telephone Telephone
Telephone line
_A
The PMs speak as if they are speaking directly to each other. For
example, when the French PM speaks, he addresses his remarks directly
to the Chinese PM. However, the message is actually passed through
two translators via the phone system. The French PM's translator
PP
translates his remarks into English and telephones these to the Chinese
PM's translator, who translates these remarks into Chinese.
b.
French PM Chinese PM
RO
Tr (F → G) Tr (G → J) Tr (J → C)
Phone Phone Phone Phone
Telephone line
VE
An intermediate node serves to translate the message before passing it
on. Note that the intermediate node handles the message only up to the
second level; a minister's level is not needed.
2.3 Perhaps the major disadvantage is the processing and data overhead.
D?
There is processing overhead because as many as seven modules (OSI
model) are invoked to move data from the application through the
communications software. There is data overhead because of the
appending of multiple headers to the data. Another possible
disadvantage is that there must be at least one protocol standard per
??
layer. With so many layers, it takes a long time to develop and
promulgate the standards.
-6-
