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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
Chapter 5
Network and Transport Layers
True-False Questions
(1)
Several different protocols exist that specify how network and/or transport layer packets are
organized.
(2)
TCP/IP is a data link protocol that is used on the Internet.
(3)
The network layer sits between the application layer and the data link layer in the Internet
five-layer network model.
(4)
The network layer is responsible for end-to-end delivery of the message.
(5)
The transport layer routes messages thought the network selecting the best path from the
source to the destination station.
(6)
The network layer depends upon the data link layer for error-free delivery of messages
from one computer to the next.
(7)
The transport layer process running on the destination computer, reassembles the
fragmented application message before passing it up to the application layer
(8)
Software with multiprotocol stacks refers to the fact that the software supports several
different transport/network protocols.
(9)
Some network protocols, such as TCP/IP, are compatible with a variety of different data
link layer protocols, such as Ethernet or frame relay.
(10) TCP is the network layer protocol used on the Internet today.
(11) IP is responsible for error-free delivery of packets on a TCP/IP network.
(12) The TCP portion of TCP/IP performs a data presentation/formatting function.
(13) The source port identifier in the TCP header tells the TCP software on the destination
computer, which application on the destination it should pass the packet too.
(14) TCP includes a sequence number so that the packets can be reassembled at the destination
in the correct order.
(15) The latest version of IP is IPv7, which increases the address space from 128 bits to 256
bits.
(16) IPX/SPX is the primary network protocol uses by Microsoft networks.
(17) IPX is the transport layer process and is responsible for the error-free delivery of data on an
IPX/SPX network.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
(18) X.25 is primarily used in local area networks
(19) To help determine to which application a transmission should be delivered on a particular
computer, TCP uses the application layer port addresses to distinguish among many open
applications on a computer
(20) Source port address is the logical address generated by the application layer on the source
computer to identify the application, which is sending the data.
(21) The standard port number for Telnet is 53.
(22) Because there is a limit on the length of a frame that the data link layer can transmit from
node to node, the transport layer breaks up the message from the application layer into
several smaller packets.
(23) Connectionless routing sets up a TCP connection, or virtual circuit between a sender and
receiver.
(24) TCP/IP operates only as connection-oriented.
(25) Quality of Service routing is a special type of connection-oriented routing in which
different connections are assigned different priorities.
(26) An example of an application layer address is www.indiana.edu
(27) The network layer address for IP is ten bytes long when using IPv4.
(28) The data link layer address is generally encoded in a network card by the card’s
manufacturer.
(29) IPv4 addresses offer unlimited opportunity for expansion and growth on the Internet.
(30) Subnet masks tell computers what part of an IP address is to be used to determine whether
a destination is in the same subnet or in a different subnet.
(31) Two standards for dynamic addressing for TCP/IP networks are: Bootstrap Protocol and
Dynamic Host Control Protocol.
(32) Translating an application layer address to a network layer address and finally to a data link
layer address is called address resolution.
(33) Part of the function of address resolution is translating the application layer address of the
destination into a network layer address.
(34) Domain Name Servers provide the equivalent of directory assistance for application layer
addresses.
(35) An Address Resolution Protocol message is broadcast to all computers in a subnet to find
the data link layer address.
(36) Routing is the process of determining the path or route through the network that a particular
message will follow from the sender to the recipient
J. FitzGerald and A. Dennis. Business Data Communications and Networking, John Wiley & Sons, Inc., 9th Edition 2006.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
(37) There are four fundamental approaches to routing: centralized, static routing, dynamic
routing, and monitor routing.
(38) When using dynamic routing, routing decisions are always made by a central host or server.
(39) A hop in a routing calculation is defined as one link or circuit.
(40) An autonomous system is a network operated by one organization.
(41) A routing protocol used inside an autonomous system is called an exterior routing protocol.
(42) Enhanced Interior Gateway Routing Protocol is a dynamic link state interior routing
protocol developed by Cisco.
(43) A multicast message can be used to send a message to a maximum of two other computers.
MULTIPLE CHOICE
The following are possible multiple-choice questions for tests. The question is posed and the
answer is provided under the choices. The level of difficulty (easy, moderate, difficult) and the
page number(s) relevant to the topic is also furnished.
1.
The ____________ layer links the application layer with the network layer is responsible for
end-to-end delivery of messages.
a. physical
b. transport
c. session
d. presentation
e. data link
2.
On the destination station, the ________ layer is responsible for providing error-free
messages to the ________ layer.
a. network, data link
b. application, transport
c. data link, network
d. physical, data link
e. transport, application
3.
__________ is not an important function of the transport layer.
a. end-to-end delivery of the message
b. taking messages from the application layer
c. routing
d. breaking long messages into smaller packets
e. interfacing with the network layer
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Chapter 5 – Network and Transport Layer
4.
5.
Dr. Hussein Al-Bahadili
Network _______ are important to ensure that hardware and software from different vendors
operated by different companies can communicate.
a. protocols
b. directories
c. frequencies
d. topologies
e. directions
_______ is the dominant network protocol today.
a. SDLC
b. SNA
c. IPX/SPX
d. TCP/IP
e. X.25
6.
Transmission Control Protocol/Internet Protocol was developed for ________ in 1974.
a. ARPANET
b. IBM
c. Hewlett-Packard
d. University of Minnesota
e. Xerox
7.
TCP/IP:
a. is the least commonly used network protocol for LANs because it cannot be
combined with Ethernet
b. performs packetizing, as well as routing and addressing functions
c. is not very efficient and is prone to errors
d. is compatible with only one type of data link protocol, SDLC
e. refers to Telephone Control Procedures/Inter-exchange Procedures
8.
A typical TCP packet has a _______ header of control information.
a. 32-bit
b. 64-bit
c. 160-bit
d. 192-bit
e. 32-byte
9.
The source destination port identifier tells the destination station _____________.
a. which computer sent the TCP packet.
b. which application layer program that the packet should be sent
c. which application layer process the packet is from.
d. the IP address of the source computer.
e. the IP address of the destination computer.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
10.
TCP uses _____________ so that the destination station can reassemble the packets into the
correct order.
a. IP addresses
b. sequence numbers
c. port numbers
d. packet numbers
e. reassembly value
11.
The older version of IP has a ________ header of control information.
a. 128-bit
b. 192-bit
c. 1024-bit
d. 160-bit
e. 320-bit
12.
IP:
a.
b.
c.
d.
e.
13.
14.
15.
performs packetizing functions
does not have a header
is currently in use with only one packet form or structure
performs routing functions
performs error control functions
The newer form of IP, version 6 (Ipv6) is:
a. running out of address space to support the growth of the Internet
b. has a 20 byte header
c. has an increased address size from 32 bits to 128 bits
d. does not include version number in its header
e. does not include hop limit in its header
Difficulty: Moderate
p. 147
IPX/SPX:
a. refers to Intermodulation Protocol Exchange/Serial Protocol Exchange
b. is the primary network protocol used by Microsoft NT networks
c. is based on a routing protocol developed by IBM in the 1990s
d. is not similar to TCP/IP in function can not be used with Ethernet
e. performs packetizing, as well as addressing and routing functions
In the IPX/SPX network model, ______is the network layer protocol and performs the same
routing and addressing functions as its counterpart IP in the TCP/IP model.
a. IPX
b. SPX
c. SAP
d. NCP
e. UDP
J. FitzGerald and A. Dennis. Business Data Communications and Networking, John Wiley & Sons, Inc., 9th Edition 2006.
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Chapter 5 – Network and Transport Layer
16.
X.25:
a.
b.
c.
d.
e.
Dr. Hussein Al-Bahadili
does not perform routing functions
is a network standard used in wide area networks
is extensively used in North America by domestic (non-international) companies
is relatively new, therefore it is not used by many organizations
has one part that handles addressing and packetizing
17.
Assume that more than one application programs that are using the same communications
line on a particular computer. To be able to decide to which application program a message
should be delivered on this computer, TCP/IP relies on the:
a. data link layer address
b. port address
c. application layer address
d. network address
e. IP address
18.
The transport layer must break messages from the application layer into several _____ that
can be sent to the data link layer.
a. bits
b. bytes
c. frames
d. packets
e. strings
19.
The negotiation by the transport layer at the sender with the transport layer at the receiver to
determine what size packets should be set up is done via establishing a(n) ___________
between the sender and receiver.
a. network layer address resolution
b. one way handshake
c. SNA message
d. TCP connection
e. DNS server request
20.
A virtual circuit is established in the ___________ routing method.
a. asynchronous
b. connection-oriented
c. frequency division
d. application net
e. connectionless
21.
A special packet called a(n) _____________ packet is sent to the receiver requesting the
establishment of a connection
a. ACK
b. NAK
c. SYN
d. ARQ
e. FIN
J. FitzGerald and A. Dennis. Business Data Communications and Networking, John Wiley & Sons, Inc., 9th Edition 2006.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
22.
_____________ routing is a method of routing in which each packet makes its own way
through the network.
a. Frequency division
b. Connection-oriented
c. PCMCIA
d. Connectionless
e. Application net
23.
In connection-oriented routing, the _________ layer sets up a virtual circuit between the
sender and the receiver.
a. transport
b. network
c. physical
d. data link
e. connection
24.
Which of the following is not a protocol used at the application layer.
a. HTTP
b. SMTP
c. FTP
d. Telnet
e. UDP
25.
______________ routing is most commonly used when the application data or message can
fit into one single packet.
a. Frame-oriented
b. Connection-oriented
c. Connectionless
d. Physical-oriented
e. Byte-oriented
26.
UDP is not commonly used for:
a. network management control messages
b. RIP messages
c. DHCP addressing messages
d. HTTP requests
e. routing control messages
27.
With QoS routing different __________ are defined, each with different priorities.
a. classes of service
b. domain names
c. application layer addresses
d. data link layer addresses
e. classes of Internet addresses
J. FitzGerald and A. Dennis. Business Data Communications and Networking, John Wiley & Sons, Inc., 9th Edition 2006.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
28.
An application layer address using TCP/Ipv4 looks like:
a. 128.192.78.5
b. www.cba.uga.edu
c. [email protected]
d. 00-0F-00-81-14-00
e. Building 4, Room 2, User 3
29.
A client computer is assigned a data link layer address is by:
a. hardware manufacturers
b. software manufacturers
c. middleware manufacturers
d. network managers who configure a file in a computer’s network layer software
package
e. ISO
30.
ICANN:
a. developed the IPX/SPX network layer protocol
b. assigns data link layer addresses
c. approves which network layer addresses (usually, approved or assigned in groups or
classes) can be used by an organization for its computers that will connect to the
Internet
d. developed X.25 network layer protocol
e. refers to Interchange Computer Addressing Networks and Nodes
31.
IPv6 will be based upon _________ -byte addresses.
a. 32
b. 24
c. 4
d. 16
e. 8
32.
IPv4 uses ________ bytes per Internet address.
a. 4
b. 32
c. 8
d. 24
e. 16
33.
A(n) ________ refers to a group of computers that are logically grouped together by IP
number.
a. IPv6 group
b. subnet
c. data link group
d. TCP group
e. application net
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
34.
A subnet mask of ___________ means that all computers with only the same first two bytes
in their IPv4 addresses are on the same subnet.
a. 11111111.0.0.0
b. 255.255.255.0
c. 255.0.0.0
d. 255.255.0.0
e. 255.255.255.255
35.
Dynamic addressing:
a. assigns a permanent network layer address to a client computer in a network
b. makes network management more complicated in dial-up networks
c. has only one standard, bootp
d. is always performed for servers only
e. can solve many updating headaches for network managers who have large, growing,
changing networks
36.
___________ is the translation of application layer addresses into IP addresses.
a. Network interface card reversal
b. IPv6
c. Server name resolution
d. Subnet masking
e. Name service coding
37.
Server name resolution is done using the:
a. Address Resolution Protocol
b. Border Gateway Protocol
c. Internet Control Message Protocol
d. Routing Information Protocol
e. Domain Name Service
38.
When TCP/IP translates an application layer address into an IP address, it sends a special
__________ to the nearest DNS server.
a. broadcast message
b. DNS request packet
c. SNA packet
d. IPX message
e. X.25 packet
39.
When TCP/IP translates a network layer address into a data link layer address, it sends a
special ____________ to all computers in the subnet.
a. physical layer packet
b. multicast message
c. X.25 message
d. broadcast message
e. application layer packet
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
40.
_________ is a specially formatted request used to perform IP address to data link address
resolution.
a. Address Resolution Protocol
b. Domain Service Request
c. HTTP request
d. Link state request
e. Autonomous System Request
41.
___________ is the process of determining the path that a message will travel from sending
computer to receiving computer.
a. Routing
b. Addressing
c. Interfacing
d. Broadcasting
e. Packetizing
42.
The _____________ is used by a computer to determine how messages will travel through
the network.
a. routing table
b. configuration listing
c. linking loader
d. bus header assignment list
e. file allocation table
43.
In its simplest form, the __________ has two columns: the first column lists every computer
and device in the network, while the second column lists the computer or device to which
that computer should send messages, if they are destined for the computer in the first column.
a. linking loader
b. routing table
c. configuration listing
d. bus header assignment list
e. file allocation table
44.
The three fundamental approaches to routing are:
a. circuitous, flat, and direct routing
b. connectionless, static, and connection-oriented
c. subordinate, master, and insubordinate routing
d. host, client, and client-server routing
e. centralized, static routing, and dynamic routing
45.
An advantage of centralized routing is:
a. routing does reflect changing network conditions, such as computers that are
overloaded by many messages
b. if anything happens to the computer developing the routing table, the routing tables
cannot be changed until that computer is fixed, or until a new computer is selected to
perform the function
c. routing decisions are simple
d. the routing tables are stored at all computers in the network
e. it requires more processing by each computer or router in the network than dynamic
routing
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
46.
With ________ routing, computers or routers count the number of hops along a route and
periodically exchange information on the hop count with their neighbors.
a. circuitous
b. decentralized
c. distance vector
d. indirect
e. link state
47.
____________ refers to the type of routing in which the routing table is developed by the
network manager and modifications are made only when computers are added to or removed
from the network.
a. Adaptive routing
b. Dynamic routing
c. Static routing
d. Distance vector routing
e. Link state routing
48.
_______________ is a type of dynamic routing.
a. Static routing
b. Circuitous routing
c. Centralized routing
d. Link state
e. X.25 routing
49.
One drawback to dynamic routing is:
a. Routing usually does not reflect changing network conditions, such as computers that are
overloaded by many messages
b. It cannot be used with non-government networks
c. The transmission of status information “wastes” network capacity that could be used to
send user messages
d. It is the job of the network manager, not the computers or devices themselves, to
maintain the routing table.
e. It requires less processing by each computer than static routing.
50.
The ping command uses the most basic interior routing protocol on the Internet, which is the:
a. Border Gateway Protocol
b. Internet Control Message Protocol
c. Routing Information Protocol
d. Enhanced Interior Gateway Routing Protocol
e. Open Shortest Path First
51.
A type of message that is used when sending a message from one computer to another
computer is called a:
a. unicast message
b. multicast message
c. broadcast message
d. guided message
e. radiated message
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
52.
A special type of message that is used when sending the same message to a specific group of
computers is called a:
a. unicast message
b. multicast message
c. broadcast message
d. guided message
e. radiated message
53.
A special type of message that is used when sending the same message to all computers on a
specific LAN or subnet is called a:
a. unicast message
b. multicast message
c. broadcast message
d. guided message
e. radiated message
54.
IGMP refers to:
a. Internet Giga Memory Parameters
b. Interchange Group Management Parameters
c. Internet Guided Meta Protocol
d. Internet Group Management Protocol
e. Interchange Guided Meta Protocol
55.
Which of the following is not given to a client computer that is installed on a TCP/IP
network so that it has the appropriate routing/addressing information?
a. application layer address
b. subnet mask
c. its own IP address
d. IP address of its DNS server
e. IP address of a gateway, router, or a switch outside of its subnet
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
Short Answer and Essay Questions
(1)
What does the network layer do? Where does it sit in relationship to the other four layers of
our simplified network model?
(2)
What are the parts of TCP/IP and what do they do? Who is the primary user of TCP/IP?
(3)
What are the parts of X.25 and what do they do? Who is the primary user of X.25?
(4)
Compare and contrast the three types of addresses used in a network.
(5)
What are the different classes of Internet addresses and how are they different?
(6)
What is a subnet and why do networks need them? What is a subnet mask?
(7)
How does dynamic addressing work? What benefits and problems does dynamic
addressing provide?
(8)
What is address resolution? How does TCP/IP perform address resolution for network layer
addresses? How does TCP/IP perform address resolution for data link layer addresses?
(9)
What is routing? How does decentralized routing differ from centralized routing? How
does static routing differ from dynamic routing? When would you use static routing? When
would you use dynamic routing? How does static routing differ from dynamic routing?
When would you use static routing? When would you use dynamic routing?
(10) What are the differences between connectionless and connection-oriented routing? Discuss
this in detail and also do a schematic of this. When might UDP be used? TCP? What is a
virtual circuit? What is Quality of Service routing and why is it useful?
(11) Compare and contrast unicast, broadcast, and multicast messages. Explain how
multicasting works.
(12) Explain how the client computer in the LAN figure in the book would obtain the data link
layer address of its subnet gateway.
(13) Explain how TCP/IP works in a high level way, using a detailed diagram including the
different roles of TCP vs. IP, and the times at which each function is utilized in the process.
(14) List and describe five reasons why TCP/IP has become the predominant protocol for
Internet level transport applications. What do you think is the future market share potential
for proprietary standards? What are some limitations of TCP/IP in terms of future Internet
growth capabilities?
(15) What is a routing table? What is the simplest form of a routing table?
(16) What is a virtual circuit?
(17) Suppose a client computer wants to access a web page on a web server. Assume that it
knows all of the IP addresses and data link layer addresses in the network, except those for
J. FitzGerald and A. Dennis. Business Data Communications and Networking, John Wiley & Sons, Inc., 9th Edition 2006.
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Chapter 5 – Network and Transport Layer
Dr. Hussein Al-Bahadili
the web server itself. Describe how the client would obtain the IP address for the web
server.
(18) Suppose a client computer wants to access a web page on a web server. Assume that it
knows all of the IP addresses and data link layer addresses in the network, except those for
the web server itself. If the web server was on the same subnet as the client, how would the
client obtain the data link layer address for the web server?
(19) Under what conditions does decentralized dynamic routing provide better performance than
decentralized static routing?
(20) What is DHCP and why would network managers want to use it?
(21) Explain how multicasting works.
(22) What four pieces of information does a computer using TCP/IP need in order to send
messages using TCP/IP. Explain why each of these is required.
(23) Suppose your manager asks you to discuss how the company’s backbone network functions
in just about four paragraphs to take to senior management. How would you answer the
question? Discuss two or three major points. Your manager doesn't understand technical
terms so be sure to explain any jargon you use.
(24) What is the difference between centralized routing and decentralized routing? What is the
difference between static routing and dynamic routing? What is a distance vector
algorithm and what is a link state algorithm? What is interior routing and what is exterior
routing? Define and describe RIP, OSPF, EIGRP, BGP protocols using these terms. Draw
a schematic diagram of routing on the internet with BGP, OSPF, and RIP.
(25) Draw an example of a NAT, including an example of a “realm” with fake IP addresses, and
include the WAN and LAN side source and destination IP’s and ports in your example.
Discuss NAT. What is its purpose? How does the router know what to do with incoming
packets? What does a NAT enabled router look like to the outside world? What does NAT
have to do with IPv6?
(26) Be able to convert back and forth between binary and decimal notation for IP addresses,
v4.
(27) Draw a schematic of the Domain Name Server process. Describe how this system works
and is hierarchically organized. What happens if a URL is not in a local DNS server?
(28) What is ARP and how and why does it work? What is MAC address resolution and how
does it work?
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