Download Ch 9 Ques

Name: __________________________ Date: _____________
1. ____________ are companies that build a data and telecommunications infrastructure
from which other companies can lease services for WANs and MANs.
A) Common carriers
B) Router manufacturers
C) Standards organizations
D) CSUs
E) PUCs
2. Each state or Canadian province has its own ___________ to regulate communications
within its borders.
A) CRTC
B) Federal Communications Commission
C) common carriers
D) public utilities commission
E) PTT
3. The _________________ is a Canadian government agency that regulates voice and
data communication.
A) PSTN
B) FCC
C) CRTC
D) CSU
E) POTS
4. Which of the following is not one of the large interexchange carriers operating in North
America today?
A) Sprint
B) DSU
C) MCI Worldcom
D) AT&T
E) none of the above is an IEC
5. ________ is a type of WAN connection that uses the normal voice telephone network.
A) ATM
B) Dial-up service
C) T-Carrier services
D) Digital Subscriber Line
E) X.25
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6. When a person uses a regular modem to make a connection to an Internet service
provider through POTS, the data travels over a:
A) dedicated circuit
B) dialed circuit
C) ISDN circuit
D) VPN circuit
E) T-1 carrier circuit
7. Special rate services that allow dialed circuit calls for both voice communications and
data transmission to be purchased in large quantities are known as __________
A) DSL
B) RBOC
C) ATM
D) WATS
E) X.25
8. Which of the following is not a problem with dialed circuits?
A) Data transmission rates on dialed circuits are relatively low.
B) Dialed circuits may vary in quality.
C) Transmission rates for dialed circuits can vary with each call.
D) It is hard to predict if a given connection will be clear or noisy.
E) Use of these circuits is very simple.
9. Adoption of narrowband ISDN in North America has been:
A) fast
B) slow
C) rapid
D) non existent, since it is not offered in North America
E) none of the above
10. A ____________ identifies each device connected to an ISDN network terminator.
A) NIC
B) MAC address
C) SPID
D) PRI
E) BRI
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11. Basic rate interface:
A) is typically offered only to commercial customers
B) provides a communications circuit with two 64 Kbps B channels, plus one D
channel
C) is defined exactly the same way in Europe
D) has an upper capacity of 1.544 Mbps
E) is comprised of analog circuits only
12. Primary rate interface:
A) is typically offered only to commercial customers
B) provides a communications circuit with two 64 Kbps B channels, plus one D
channel
C) is defined exactly the same way in Europe
D) has an upper capacity of 128Kbps
E) is comprised of analog circuits only
13. One type of Broadband ISDN service is intended to be used for digital broadcast
television:
A) analog service
B) asymmetrical service with two simplex channels
C) one full duplex channel operating at 155.52 Mbps
D) packet-switched service
E) one full duplex channel operating at 622.08 Mbps
14. A ___________ is/are devices that permit a user to connect to a digital T-carrier service.
A) modem
B) codec
C) CSU/DSU
D) NIC
E) ATM
15. Which of the following is not a basic architecture for dedicated circuit networks?
A) ring
B) partial mesh
C) bus
D) star
E) fully interconnected mesh
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16. A ________ geometric layout connects all computers in a closed loop, with each
computer linked to the next usually with a series of point-to-point dedicated circuits.
A) bus design
B) star design
C) full mesh design
D) ring design
E) partial mesh design
17. In a ring design WAN,
A) messages can take a long time to travel from the sender to the receiver
B) a message arrives at all computers on the network simultaneously
C) messages always arrive faster than in other types of layouts
D) messages are delivered directly from sender to receiver because there is a point-topoint connection directly between each sender and each receiver
E) messages always take one second to travel between sender and receiver
18. In a ring design WAN,
A) failure in one circuit means that the network can most likely continue to function
B) failure in one circuit always means that the network will cease to function
C) failure in one computer always means that the network will cease to function
D) failure in one circuit means that there will not be any increased traffic delays in the
network
E) failure in one computer always means that messages will stop at that computer since
it would be impossible to re-route traffic
19. A star architecture:
A) connects all computers in a closed loop
B) connects all computers off a backbone circuit
C) connects all computers to one central computer that routes messages to the
appropriate computer
D) all of the above
E) none of the above
20. A _______ geometric layout for a WAN connects all computers to one central computer
that routes messages to the appropriate computer, usually via a series of point-to-point
dedicated circuits.
A) ring design
B) mesh design
C) bus design
D) star design
E) the circular design
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21. A star topology is:
A) difficult to manage because the central computer receives and routes all messages in
the network
B) dependent upon the capacity of the central computer for its performance
C) always slower than a ring network
D) less susceptible to traffic problems than other architectures
E) not affected if the central computer fails
22. In ______ geometric layout for a network, every computer is connected to every other
computer often by point-to-point dedicated circuits.
A) full mesh design
B) ring design
C) star design
D) bus design
E) partial mesh design
23. Mesh networks:
A) usually provide relatively long routes through the network (compared to ring
networks)
B) require more processing by each computer in the network than in star or ring
networks
C) do not use decentralized routing
D) do not have much capacity wasted by network status information
E) do not have many possible routes through the network to prevent one circuit from
becoming overloaded
24. _____ are dedicated digital circuits that are the most commonly used form of dedicated
circuit services in North America today.
A) Wideband analog services
B) SMDS
C) ATM
D) T-carrier services
E) ISDN
25. The data rate for a T-1 circuit in North America is:
A) 1.544 Mbps
B) 6.312 Mbps
C) 44.376 Mbps
D) 274.176 Mbps
E) 1.544 Gbps
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26. In North America, a T1 circuit has ______ 64Kbps channels.
A) 2
B) 30
C) 24
D) 12
E) 36
27. The data rate for a T-3 circuit in North America is:
A) 1.544 Mbps
B) 6.312 Mbps
C) 44.376 Mbps
D) 274.176 Mbps
E) 1.544 Gbps
28. SONET:
A) is a standard for optical transmission that currently operates at Terabit per second
speeds
B) is very similar to the ITU-T standard, synchronous digital hierarchy
C) uses inverse multiplexing above the OC-1 level
D) refers to Sprint Overall Network
E) is not currently available, even in large cities
29. Which of the following is not a benefit of packet switched services?
A) The data transmission rates tend to be lower than dial-up or dedicated circuits.
B) You don't have to set up dedicated circuits between each end point from and to
which you wish to transmit data and/or voice.
C) You have the flexibility to send data through a temporary circuit between two
connections that will be disconnected as soon as the digital transmission is
completed.
D) All circuits are less susceptible to a great deal of noise because they are digital.
E) You don't have to specify all the interconnecting services you need for your WAN
when you buy the service.
30. A _____________ is a user's connection into a packet switched service.
A) packet analog/digital device
B) packet asynchronous/discrete device
C) packet asymmetric/data transmission device
D) packet assembly/disassembly device
E) packet analyzer/decoder device
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31. Which of the following type of networks permit packets from separate messages to be
interleaved?
A) circuit switched network
B) dedicated circuit network
C) dial up circuit network
D) packet switched network
E) Fractional T-1 network
32. A _______ is a connectionless method of sending data packets on a packet switched
service.
A) bursty packet
B) virtual circuit
C) datagram
D) histogram
E) permanent virtual circuit
33. A _________ is a connection-oriented approach to sending packets on a packet switched
service.
A) permanent virtual circuit
B) datagram
C) histogram
D) bursty packet
E) fractional T-1 network
34. In a packet switched network, permanent virtual circuits that look very similar to a
_____________ (for hardware-based dedicated circuits) move packets through the
network.
A) cloud-based ring design
B) cloak-based mesh design
C) cloud-based mesh design
D) common carrier ring design
E) common carrier bus design
35. Which of the following is not true about X.25?
A) It is the oldest type of packet switched service.
B) It offers datagram, switched virtual circuit, and permanent virtual circuit services.
C) It uses the LAPB data link layer protocol.
D) It is a type of circuit switched service.
E) It is not used widely in North America, except by multinational companies.
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36. ____________ is a newer type of packet switching technology.
A) ATM
B) SONET
C) ISDN
D) ADSL
E) X.25
37. Which of the following is not a difference between ATM and X.25?
A) ATM networks do not perform error control at each node, or computer, in the
network.
B) ATM provides packet switched service.
C) ATM is scalable.
D) ATM provides quality of service information used for setting different priorities for
packet transmission
E) ATM has cells that are 53 bytes long.
38. Which of the following is a difference between ATM and frame relay?
A) Frame relay encapsulates packets.
B) Frame relay is an unreliable packet service.
C) Frame relay has a maximum CIR speed of up to 45 Mbps.
D) Frame relay does not perform error control at each node in the network.
E) Frame relay provides packet switched service.
39. SMDS:
A) is not yet a widely accepted standard
B) refers to Subscriber Mainframe Digital Subscriber
C) performs error checking, unlike frame relay and ATM
D) does not encapsulate packets
E) is a reliable packet service
40. Ethernet/IP packet networks:
A) are supported with gigabit fiber optic networks in large cities
B) are offered only by the common carriers
C) use token ring layer 2 media access control
D) use IPX/SPX protocols
E) provide CIR up to a maximum of 1.544 Mbps
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41. A _______________ is particular type of network that uses circuits that run over the
Internet but that appears to the user to be a private network.
A) local carrier network
B) virtual private network
C) integrated service digital network
D) software defined network
E) SONET network
42. With a virtual private network, users create permanent virtual circuits through the
Internet called:
A) bursts
B) cells
C) tunnels
D) rings
E) clouds
43. Which of the following is an advantage of a VPN?
A) low cost
B) inflexibility
C) unpredictable traffic congestion
D) security
E) complexity to the user
44. _____________ is an emerging standard for use by layer 2 access VPNs for
encapsulation.
A) L2TP
B) VPN2
C) Encapsule2
D) TCP/IP
E) PPP
45. Which of the following is not a type of VPN?
A) intranet VPN
B) extranet VPN
C) access VPN
D) T-1 VPN
E) a VPN that enables employees to access an organization's network from a remote
location
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46. __________ is a term that refers to the speed in converting input packets to output
packets.
A) Transfer mode
B) Latency
C) Burstiness
D) Cell relay
E) Frame relay
47. The performance of MANs and WANs can be improved by:
A) upgrading the circuits between the computers
B) increasing the demand placed on the network
C) downgrading the circuits between the computers
D) downgrading the devices that provide access to the circuits
E) increasing network traffic
48. Dynamic routing:
A) imposes an overhead cost by increasing network traffic
B) decreases performance in networks which have many possible routes
C) decreases performance in networks with “bursty” traffic
D) should be used in 80 to 90 percent of total networks' capacity
E) is another term for static routing in WANs
49. Which of the following is not a way to reduce network demand?
A) shifting network usage from high cost times to lower cost times
B) using data compression techniques for all data in the network
C) requiring a network impact statement for all application software developed by the
organization
D) moving data further from the applications and people who use them
E) shifting network usage from peak to lower demand times
50. Which of the following is not a key issue to be considered when selecting a WAN
service?
A) prestige value of using a particular common carrier
B) flexibility
C) capacity
D) control
E) reliability
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51. If you have a low volume of message traffic on a small WAN or MAN, _________
service is recommended, but if you have a high traffic, large WAN or MAN,
__________ service would be more cost effective.
A) dedicated, dial-up
B) packet, dial-up
C) inward, outward
D) outward, inward
E) dial-up, packet
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