This is the Multiple Choice Questions in Chapter 11: Wide-Area Networks and the Internet from the book Electronic Communication Systems by Roy Blake
Start Practice Exam Test Questions
Choose the letter of the best answer in each questions.
MULTIPLE CHOICE
1. MAN stands for:
- a. Manchester Access Network
- b. Multiple-Area Network
- c. Metropolitan-Area Network
- d. Multiple Access Network
ANS: C
2. Packet switching is based on:
- a. store-and-forward
- b. switched circuits
- c. real-time delivery
- d. all of the above
ANS: A
3. SNA stands for:
- a. Standard Network Access
- b. Small Network Access
- c. Standard Network Architecture
- d. Systems Network Architecture
ANS: D
4. The number of layers in ISO OSI is:
- a. 3
- b. 5
- c. 7
- d. 8
ANS: C
5. The lowest-level layer in ISO OSI is called the:
- a. physical layer
- b. link layer
- c. cable layer
- d. transport layer
ANS: A
6. Bad frames are usually detected by the:
- a. frame layer
- b. physical layer
- c. error-check layer
- d. link layer
ANS: D
7. A virtual circuit is set up by the:
- a. user
- b. link layer
- c. network
- d. frame
ANS: C
8. Frame Relay:
- a. is faster than X.25
- b. does less error checking than X.25
- c. allows for variable length packets
- d. all of the above
ANS: D
9. ATM stands for:
- a. Asynchronous Transfer Mode
- b. Asynchronous Transmission Mode
- c. Asynchronous Transmission Model
- d. Automatic Test Mode
ANS: A
10. A bridge:
- a. separates a network into "collision domains"
- b. looks at the address of each packet
- c. operate at the data-link level
- d. all of the above
ANS: D
11. IP stands for:
- a. Internet Process
- b. Internet Protocol
- c. Interconnect Protocol
- d. Interconnect Procedure
ANS: B
12. TCP stands for:
- a. Transmission Control Process
- b. Transmission Control Protocol
- c. Transfer Connection Protocol
- d. none of the above
ANS: B
13. Together, TCP/IP consists of:
- a. 5 layers
- b. 7 layers
- c. an application and a process
- d. datagrams
ANS: A
14. IP is a:
- a. connection-oriented protocol
- b. virtual circuit
- c. connectionless protocol
- d. non-robust protocol
ANS: C
15. The "lifetime" of a packet in an IP network:
- a. is essentially forever
- b. depends on elapsed time since transmission
- c. depends on number of "hops" between nodes
- d. is approximately 200 milliseconds
ANS: C
16. UDP stands for:
- a. User Datagram Protocol
- b. User Data Protocol
- c. User Data Packet
- d. Universal Data Packet
ANS: A
17. HTTP stands for:
- a. High-speed Transmission Test Procedure
- b. High-Level Transfer Test Procedure
- c. Hypertext Transmission and Transport Procedure
- d. Hypertext Transport Protocol
ANS: D
18. HTTP allows the use of:
- a. dumb terminals
- b. file transport
- c. browsers
- d. none of the above
ANS: C
19. HTML stands for:
- a. Hypertext Markup Language
- b. Hypertext Transfer-Mode Level
- c. Hypertext Transfer-Mode Layer
- d. High-speed Transfer-Mode Language
ANS: A
20. HTML allows:
- a. telneting
- b. high-speed file transfer
- c. web page layout
- d. all of the above
ANS: C
21. FTP stands for:
- a. File Transfer Protocol
- b. File Transport Protocol
- c. File Test Procedure
- d. Fast Transport Packet
ANS: A
22. FTP is used to:
- a. transfer files between a server on the network and a user
- b. test files to see if their data has been "corrupted"
- c. transport packets at maximum speed through the network
- d. none of the above
ANS: A
23. SMTP stands for:
- a. Short Message Transport Protocol
- b. Simple Message Transport Protocol
- c. Simple Mail Transport Protocol
- d. Secondary Mail Transfer Procedure
ANS: C
24. ISP stands for:
- a. Internet Service Protocol
- b. Internet Service Provider
- c. Internet Service Procedure
- d. none of the above
ANS: B
25. The standard Internet address (or URL) is:
- a. a 32-bit binary number
- b. four groups of base-ten numbers
- c. running out of available values
- d. all of the above
ANS: D
26. DNS stands for:
- a. Domain Name Server
- b. Domain Name System
- c. Domain Numbering System
- d. Domain Naming System
ANS: A
27. A DNS:
- a. has become obsolete on the Internet
- b. translates words to numbers
- c. stores all domain addresses
- d. describes the Internet address-naming procedure
ANS: B
28. An intranet connected to the Internet is often protected by:
- a. a DNS
- b. a "brick wall"
- c. a "firewall"
- d. the use of "spoofing" protocols
ANS: C
29. OSI stands for:
- a. Open Systems Interconnection
- b. Open Standard Interconnection
- c. Open Systems Internet
- d. none of the above
ANS: A
COMPLETION
1. A ____________________-Area Network would extend typically across a city.
ANS: Metropolitan
2. A ____________________-Area Network could extend across a nation.
ANS: Wide
3. A dedicated telephone line can be ____________________ on a monthly basis.
ANS: leased
4. The use of digital circuit-____________________ lines is cheaper than dedicated lines.
ANS: switched
5. Packet switching is done on a store-and-____________________ network.
ANS: forward
6. A ____________________ is a hierarchy of procedures for implementing digital communications.
ANS: protocol
7. Voltage levels on a cable are specified at the ____________________ layer.
ANS: physical
8. Bad frames are usually detected at the ____________________ layer.
ANS: data-link
9. Setting up a path through the network is done by the ____________________ layer.
ANS: network
10. The X.25 protocol was developed by the ____________________.
ANS: CCITT
11. In X.25, the data-link layer is called the ____________________ layer.
ANS: frame
12. In X.25, the network layer is called the ____________________ layer.
ANS: packet
13. The physical route of a ____________________ circuit changes each time it is used.
ANS: virtual
14. Frame Relay requires channels with low ____________________ rates.
ANS: bit-error
15. Compared to X.25, Frame Relay does ____________________ error checking.
ANS: less
16. All ATM frames contain just ____________________ bytes.
ANS: 53
17. Small frame size and a high-speed channel allow ____________________-time communications.
ANS: real
18. ____________________ simply regenerate and retransmit packets in a network.
ANS: Repeaters
19. ____________________ look at the address inside a packet to decide whether or not to retransmit it.
ANS: Bridges
20. ____________________ decide the best network path on which to forward a packet.
ANS: Routers
21. TCP/IP goes back to the ____________________ of the 1970s.
ANS:
ARPANET
DARPANET
22. Between ISO OSI and TCP/IP, ____________________ was used first.
ANS: TCP/IP
23. A ____________________ protocol does not track packets after they are sent.
ANS: connectionless
24. HTTP allows the use of ____________________ that jump to other pages on the web.
ANS: hyperlinks
25. The Internet "backbone" mostly uses high-speed ____________________ cables.
ANS: fiber-optic
26. A ____________________ translates words in an Internet address to numbers.
ANS: DNS
27. Intranets usually connect to the Internet through a ____________________ for security.
ANS: firewall
28. Voice over ____________________ is telephony done over the Internet.
ANS: IP
29. "____________________" is another term for real-time transmission over the Internet.
ANS: Streaming
30. Most people gain access to the Internet by subscribing to an ____________________.
ANS: ISP
SHORT ANSWER
1. Name the three parts of an IP address as used on the Internet.
ANS:
Network number, Subnet number, Host number
2. Why is a logical channel called a "virtual" circuit?
ANS:
A logical channel is a way of keeping track of which two nodes on the network have messages for each other. The actual physical path can change while packets are being sent. Virtual means it behaves like direct circuit between 'A' and 'B', but it is not a direct circuit.
3. Why is it faster to send packets of a fixed size compared to packets of variable size?
ANS:
The processing required to store and forward packets of different lengths is greater than that required for packets of a fixed length. More processing implies more time per packet, which implies fewer packets per second through the network.
4. Why are the tasks involved in digital communications divided into layers in a protocol stack? Why not just have one layer that does it all?
ANS:
Divide and conquer: it reduces complexity to a manageable job. One big layer could not be adapted to newer media etc as easily as a system of independent layers. Think of subroutines in a computer program.
5. What is a "hop"?
ANS:
Every time a packet is forwarded on to the next store-and-forward node in the network, it is considered to be one "hop".
6. What does it mean to say a packet has a lifetime measured in hops?
ANS:
Each packet contains a number representing the maximum number of allowed hops. At each hop, this number is reduced by one. When it gets to zero, the packet is deleted from the network.
7. Why should packets have a lifetime?
ANS:
If they didn't, then the number of "lost" packets traveling around the network would continuously increase. At some point, there would be no bandwidth left to carry real traffic.
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