Application Layer

Chapter 2

Application Layer

True-False Questions

The following are possible True/False questions for tests. The statement is given and the answer is provided in square brackets. The level of difficulty (easy, moderate, difficult) and the page number(s) relevant to the topic are also furnished.

An application architecture is the way in which the functions of the application layer are performed solely by the clients in the network.
Answer:False
Difficulty:Moderate
Reference: Application Architectures
The four general functions of any application program are: data storage, data access logic, application logic and presentation logic.
Answer:True
Difficulty: Easy
Reference: Application Architectures
A cluster is a group of computers that are linked together so they act as a one computer.
Answer:True
Difficulty: Easy
Reference: Technical Focus
A network computer is designed primarily to communicate using Internet based standards, but has no hard disk. It has only limited functionality.
Answer:True
Difficulty:Easy
Reference: Technical Focus
Host-based and client-based networks are similar in that the client computer performs most of the work.
Answer:False
Difficulty:Easy
Reference: Application Architectures
The earliest data communications networks were client-server networks.
Answer: False
Difficulty: Easy
Reference: Host-Based Architectures
As the demand for more and more network applications grow; host-based computing becomes thebest solution.
Answer:False
Difficulty:Moderate
Reference: Host-Based Architectures
One major drawback to a client-server network lies in the fact that client-server networks enable software and hardware from different vendors to be used together.
Answer:False
Difficulty:Moderate
Reference:Client-Server Architectures
In a client-server network, the presentation logic is the responsibility of the client computer.
Answer: True
Difficulty: Easy
Reference: Client-Server Architectures
The two functions of middleware are to: 1) provide a standard way of communicating that can translate between software from different vendors, and 2) manage the message transfer between clients and servers so that clients do not need to ‘know’ which server contains the application’s data.
Answer: True
Difficulty:Moderate
Reference: Client-Server Architectures
Middleware is the software that sits between the application software on the client and the application software on the server.
Answer:True
Difficulty:Easy
Reference: Client-Server Architectures
In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.
Answer:True
Difficulty:Moderate
Reference: Two-Tier, Three Tier, and n-Tier Architectures
A “thin client” approach places most of the application logic on the client.
Answer:False
Difficulty:Easy
Reference: Thin Clients versus Thick Clients
The application architecture called the distributed computing model uses the “thick” client approach.
Answer:False
Difficulty:Moderate
Reference: Thin Clients versus Thick Clients
Scalability refers to the ability to increase or decrease the capacity of the computing infrastructure in response to changing capacity needs.
Answer:True
Difficulty:Easy
Reference:Scalability
To use the Web, each client computer requires a data link layer software package called a Web browser.
Answer:False
Difficulty: Easy
Reference: How the Web Works
The standard protocol for communication between a Web browser and a Web server is the web protocol.
Answer:False
Difficulty:Moderate
Reference: How the Web Works
The World Wide Web was conceived at University of Utah as part of the development of the Internet.
Answer:False
Difficulty: Easy
Reference: World Wide Web
A request header for an HTTP request starts with a command, such as GET, and ends with the HTTP version number that the browser understands.
Answer:False
Difficulty:Easy
Reference: Inside an HTTP Request
All three parts (request line, request header, request body) of an HTTP request from a web browser to a web server are required when a request is made.
Answer: False
Difficulty: Moderate
Reference:Inside an HTTP Response
The Simple Mail Transfer Protocol is the least commonly used e-mail standard.
Answer:False
Difficulty: Easy
Reference: How E-Mail Works
The two-tier e-mail architecture does not require any application software on the client computer.
Answer: False
Difficulty: Easy
Reference: Two-Tier E-mail Architecture
Using the POP standard for client to server e-mail communication, the e-mail messages remain on the server computer.
Answer: False
Difficulty: Easy
Reference:Two-Tier E-mail Architecture
Web-based e-mail like Hotmail is an example of three-tier client-server architecture that provides access to e-mail messages.
Answer: True
Difficulty: Moderate
Reference: Three-Tier Client-Server Architecture
FTP and Telnet are similar applications, because they allow you to download files from a remote computer to a local computer.
Answer: False
Difficulty: Moderate
Reference: File Transfer Protocol and Telnet

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.

A(n) ______is the way in which the functions of the application layer software are spread among the clients and servers in the network.

1. anonymous FTP
2. data access logic
3. fat client
4. application architecture
5. response status architecture

Answer:D
Difficulty: Easy
Reference: Application Architectures
A ______is a very large general-purpose computer that is capable of performing very manyfunctions as if these are done simultaneously, and storing extremely large amounts of data.

1. workstation
2. transaction terminal
3. cluster
4. mainframe
5. microcomputer

Answer:D
Difficulty: Easy
Reference: Technical Focus
Which of the following is not the type of computer commonly used as aserver:

1. microcomputer
2. network computer
3. handheld
4. mainframe computer

Answer: B
Difficulty: Easy
Reference: Technical Focus
A ______is a group of computers linked together so that they act as one computer.

1. workstation
2. transaction terminal
3. cluster
4. network computer
5. transaction terminal

Answer: C
Difficulty: Easy
Reference: Technical Focus
A ______is the type of computer you use in your home and is the most common type of client today.

1. microcomputer
2. mainframe
3. handheld
4. cluster
5. transaction terminal

Answer: A
Difficulty: Easy
Reference: Technical Focus
A ______is a group of computers linked together so that they act as one computer.

1. handheld
2. mainframe
3. network computer
4. cluster
5. transaction terminal

Answer: D
Difficulty: Easy
Reference: Technical Focus
Which of the following is not true a dumb terminal:

1. it has a monitor, keyboard and no CPU
2. all the processing takes place on the host computer.
3. it does not participate in the processing of the data it displays
4. you can install your latest application software on it.
5. it is basically an input/output device.

Answer: D
Difficulty: Moderate
Reference: Technical Focus
Which of the following is not a general function by any application program?

1. data storage
2. data access logic
3. application logic
4. presentation logic
5. application access storage

Answer: E
Difficulty: Moderate
Reference: Application Architectures
______is an application program function that deals with storing and retrieving data.

1. data storage
2. data access logic
3. application logic
4. presentation logic
5. application access storage

Answer: A
Difficulty: Easy
Reference: Application Architectures
An application program function is ______, or the processing required to access data.

1. data storage
2. data access logic
3. application logic
4. presentation logic
5. application access storage

Answer: B
Difficulty: Easy
Reference:Application Architectures
______, or the algorithms or business logic programmed into the application, can be simple or complex depending on the application.

1. data storage
2. data access logic
3. application logic
4. presentation logic
5. application access storage

Answer: C
Difficulty: Easy
Reference:Application Architectures
______is the presentation of information to the user and the acceptance of the user’s commands.

1. data storage
2. data access logic
3. application logic
4. presentation logic
5. application access storage

Answer: D
Difficulty: Easy
Reference: Application Architectures
One underlying problem with a host-based network is that:

1. there are economies of scale because all computer resources are centralized
2. the server can get overloaded since it must process all messages
3. the architecture is relatively simple and works well
4. the server is the one point of control which simplifies security
5. clients (terminals) do not require sophisticated hardware/software because they do not perform most of the work in this type of architecture

Answer: B
Difficulty: Moderate
Reference: Host-Based Architectures
With a client-based network, one fundamental problem is that:

1. the clients each must store all the data
2. the server does not have any data storage capability
3. the host or server must perform presentation logic, application logic, and data access logic at the same time
4. all data on the server must travel to the client for processing
5. the clients must perform the data storage logic

Answer: D
Difficulty: Easy
Reference:Client-Based Architectures
With the two-tier client-server architecture, the client is responsible for the ______logic and the server is responsible for the ______logic.

1. Application; presentation
2. Presentation; data access
3. Data access; presentation
4. Application; data access
5. Presentation; application storage

Answer: B
Difficulty: Moderate
Reference:Two-Tier, Three-Tier, and n-Tier Architectures
Client-server architectures:

1. cannot connect computers that use different hardware
2. are one of the least used network architectures today
3. can use middleware to provide a standard way of communicating between software from more than one vendor
4. assign the responsibility for the presentation logic to the server
5. were the earliest type of network architectures

Answer: C
Difficulty: Moderate
Reference:Client-Server Architectures
How are the application architecture functions split up in a client-server network?

1. the presentation logic and data storage are on the client, while the data access logic is on the server
2. the data storage, data access, and presentation logic are on the client
3. the presentation logic is on the client, while the data storage and data access logic are on the server
4. the data storage and data access logic are on the client, while the presentation logic are on the server
5. the presentation logic and data access logic are on the client, and the data storage is on the server

Answer: C
Difficulty: Moderate
Reference: Client-Server Architectures
In a client-server network, ______gets software from different vendors to work together.

1. a front-end processor
2. serverware
3. middleware
4. centerware
5. programmer

Answer: C
Difficulty: Easy
Reference: Client-Server Architectures
______is not an important middleware standard.

1. CORBA (Common Object Request Broker Architecture
2. Distributed Computed Environment (DCE)
3. Asynchronous Transfer Mode (ATM)
4. Open Database Connectivity (ODBC)
5. none of the above is an appropriate answer

Answer: C
Difficulty: Moderate
Reference:Client-Server Architectures
A(n) ______-tiered architecture uses only two sets of computers: one set of clients and one set of servers.

1. one
2. two
3. three
4. five
5. n

Answer: B
Difficulty: Easy
Reference:Two-Tier, Three-Tier, and n-Tier Architectures
In the three tier architecture the software on the client computer is responsible for______.

1. presentation logic
2. application logic
3. data access logic
4. data storage
5. application storage

Answer: A
Difficulty: Easy
Reference:Two-Tier, Three-Tier, and n-Tier Architectures
An N-tiered architecture:

1. is generally more “scalable” than a three-tiered architecture
2. is generally less “scalable” than a three-tiered architecture
3. uses only two sets of computers in which the clients are responsible for the application and presentation logic, and the servers are responsible for the data
4. uses exactly three sets of computers in which the client is responsible for presentation, one set of servers is responsible for data access logic and data storage, and application logic is spread across two or more different sets of servers
5. puts less load on a network than a two-tiered architecture because there tends to be less communication among the servers

Answer: A
Difficulty: Easy
Reference: Two-Tier, Three-Tier, and n-Tier Architectures
One disadvantage of the ______architecture is that places a greater load on the network.

1. two-tier
2. three tier
3. one-tier
4. n-tier
5. layered

Answer: D
Difficulty: Easy
Reference: Two-Tier, Three-Tier, and n-Tier Architectures
A “thin client” architecture approach:

1. always is a two-tier network architecture
2. always is an n-tiered architecture
3. places all or almost all of the application logic on the client
4. places all or almost all of the application logic on the server
5. refers to the size of the cable connecting the clients to the network

Answer: D
Difficulty: Easy
Reference:Thin Clients versus Thick Clients
A “thickclient” architecture approach:

1. always is a two-tier network architecture
2. always is an n-tiered architecture
3. places all or almost all of the application logic on the client
4. places all or almost all of the application logic on the server
5. refers to the size of the cable connecting the clients to the network

Answer: C
Difficulty: Easy
Reference: Thin Clients versus Thick Clients
With the “thin client” architecture, when an application changes, only the ______with the application logic needs to be updated.

1. client
2. server
3. middleware
4. hardware
5. software

Answer: B
Difficulty: Moderate
Reference: Thin Clients versus Thick Clients
With respect to costs for a client-server network, which of the following is true?

1. Personal computers used as clients in a client-server network cost about the same as mainframes for the same amount of computing power.
2. More network capacity, which costs more money, is required for client-server networks than for client-based networks.
3. Experts believe that client server architectures can be complex, but that developing application software for host based architectures is usually cheaper.
4. Updating the network with new version of software tends to be less expensive in a client-server network since the software is centralized in one client.
5. None of the above

Answer: C
Difficulty: Moderate
Reference:Cost of Development
The idea for a special hypertext network, called the World Wide Web, was conceived of by:

1. Microsoft in 1994 as part of the Windows 95 project
2. Tim Berners-Lee at the European Laboratory for Particle Physics (CERN) in 1989
3. Vinton Cerf, for the U.S. Department of Defense in 1969 as a network of four computers called ARPANET
4. Howard Flieshman of IBM in 1982 as part of the development of the IBM PC
5. the University of Minnesota as an extension of Gopher

Answer: B
Difficulty: Easy
Reference:World Wide Web
Marc Andreessen led a team that developed the first graphical Web browser, which was called:

1. Internet Explorer
2. Mosaic
3. Firebird
4. Netscape Navigator
5. Mozilla

Answer: B
Difficulty: Easy
Reference:World Wide Web
To interact with the World Wide Web, a client computer needs an application layer software package called a:

1. Web browser
2. Web server
3. Telnet package
4. Uniform Resource Locator package
5. Router package

Answer: A
Difficulty: Easy
Reference:How the Web Works
Each server on a network that needs to act as a web server needs an application layer software package called a (n) ______.

1. browser
2. application web
3. web server
4. operating system
5. none of the above

Answer: C
Difficulty: Easy
Reference:How the Web Works
To get a page from the Web, a user must type in a URL, which stands for:

1. Unknown Resource Locator
2. Unknown Router Location
3. Uniform Router Location
4. Uniform Resource Locator
5. Uniform Resource Library

Answer: D
Difficulty: Easy
Reference: How the Web Works
The protocol that makes it possible for a Macintosh web browserto be able to retrieve a Web page from a Microsoft Web server is called ______.

1. Hypertext Transfer Protocol
2. File Transfer Protocol
3. Simple Mail Transfer Protocol
4. Internet Message Access Protocol
5. Hyperlink Transfer Protocol.

Answer: A
Difficulty: Moderate
Reference: How the Web Works
There are optional and required parts of an HTTP request. They are:

1. request address, request body
2. request address, request header, request body

1. request line, request header
2. request line, request body
3. request line, request header, request body

Answer: E
Difficulty: Moderate
Reference:Inside an HTTP Request
There are required and optional parts of an HTTP response. They are:

1. response status, response header, response body
2. response address, response header, response body
3. response status, response body
4. response address, response header
5. response status, response header

Answer: A
Difficulty: Moderate
Reference:Inside an HTTP Response
A response status code of 404 means:

1. the requested page was not found
2. the server is currently unavailable
3. the sever is currently busy
4. your browser is incompatible with the Web server software.
5. your browser needs to be updated to the latest version.

Answer: A
Difficulty: Easy
Reference: Inside an HTTP Response
The acronym, HTML, refers to:

1. Header Markup Language
2. Hypertext Markup Locator
3. Hypertext Markup Language
4. Hypertext Markup Library
5. Hypertext Modulating Language

Answer: C
Difficulty: Easy
Reference:Inside an HTTP Response
Which of the following is not an advantage of instant messaging?

1. It usually takes days for an IM message to be delivered to the recipient.
2. It allows real time typed messages to be exchanged.
3. Some products are ICQ and AOL Instant Messenger.
4. It is generally faster than snail-mail.
5. It helps people avoid telephone tag.

Answer: A
Difficulty: Easy
Reference:Instant Messaging
The most commonly used e-mail standard is:

1. Simple Mail Transfer Protocol
2. X.400
3. CMC
4. Post Office Protocol
5. Telnet

Answer: A
Difficulty: Easy
Reference:How E-mail Works
In a two-tier client-server architecture, a client computer needs to use an application layer software package called a ______to send e-mail:

1. message transfer agent
2. router agent
3. user agent
4. Webcast package
5. gateway agent

Answer: C
Difficulty: Moderate
Reference:Two-tier E-mail Architecture
Which of the following is not a user agent package?

1. Outlook Express
2. Microsoft Word
3. Fedora
4. Netscape Messenger
5. Microsoft Outlook

Answer: B
Difficulty: Moderate
Reference: Two-tier E-mail Architecture
Another term for a user agent is:

1. message transfer agent
2. router agent
3. e-mail client
4. Webcast package
5. Web client

Answer: C
Difficulty: Easy
Reference:Two-tier E-mail Architecture
IMAP (Internet Message Access Protocol):

1. is a set of standards that define how email is to be processed between mail servers
2. is exactly the same as SMTP
3. copies an e-mail message from the client computer’s hard disk, deletes it from the client, and stores it on the mail server
4. is exactly the same as POP
5. permits an e-mail message to remain stored on the mail server even after they have been read by a client computer

Answer: E
Difficulty: Easy
Reference: Two-tier E-mail Architecture
A ______, a mailing list of users who discuss some topic, has two parts: a processor and a mailer.

1. listserv
2. Gopher
3. TELNET
4. ADSL
5. FTP

Answer: A
Difficulty: Moderate
Reference: Listserv Discussion Groups
To send a message to every user on a listserv, type in:

1. UNSUBSCRIBE listserv-mailer your-name
2. LIST
3. HELP
4. The mailer address name of the listserv as the address for your e-mail message
5. The processor address of the listserv as the address for your e-mail message

Answer: D
Difficulty: Moderate
Reference: Listserv Discussion Groups
The acronym, MIME, refers to:

1. Multimedia Internet Mail Enterprise
2. Multiple Internet Media Extension
3. Multipurpose Internet Mail Extension
4. Media Internet Mail Extension
5. Multimedia Internet Mime Extension

Answer: C
Difficulty: Easy
Reference:Attachments in Multipurpose Internet Mail Extensions
Which of the following is not true about File Transfer Protocol (FTP)?

1. WS-FTP is a software package that uses the FTP standard.
2. FTP sites require users to have permission before they can access the site.
3. The most common type of FTP site is anopen FTP site.
4. FTP requires an application layer program on the client as well as an FTP server application program on a server.
5. FTP enables a user to send and receive files over the Internet.

Answer: C
Difficulty: Moderate
Reference: File Transfer Protocol
The fastest growing form of videoconferencing is

1. mainframe
2. Outlook
3. Telnet
4. webcasting
5. desktop

Answer: E
Difficulty: Moderate
Reference:Videoconferencing
Which of the following is not true about Telnet?

1. Telnet requires an application layer program on the client computer and an application layer program on the server or host computer.
2. Telnet poses no security threat.
3. Telnet was designed in the early days of the Internet.
4. You are using a host-based architecture with Telnet.
5. One program that conforms to the Telnet standard is EWAN.

Answer: B
Difficulty: Moderate
Reference:Telnet
______is a special type of one directional; videoconferencing in which content is sent from the server to the user.

1. broadcasting
2. instant messaging
3. webcasting
4. H.323
5. Net Meeting.

Answer: C
Difficulty: Moderate
Reference: Video Conferencing

Essay and Short Answer Questions