Deck 8: Wide Area Networks

Question 1

The original Integrated Services Digital Network (ISDN)is also known as mediumband ISDN.

Answer 1

False

Question 2

Today,a common carrier that provides long distance services is typically called a local exchange carrier.

Answer 2

False

Question 3

In building Wide Area Networks,many organizations do not build their own long distance communication circuits

Answer 3

True

Question 4

Common carriers sell or lease communication services and facilities to the public.

Question 5

A WAN with a ring topology can use full or half duplex circuits

Question 6

POTS always uses the came circuit paths each time a number is dialed so that quality and maximum data rate is always the same.

Question 7

Full mesh networks are inexpensive.

Question 8

WANs can connect BNs across distances that can span up to thousands of miles.

Question 9

Full mesh design networks are more common than partial mesh design networks.

Question 10

T carrier circuits can only be used to transmit voice.

Question 11

Broadband ISDN (B-ISDN)uses X.25 to move packets through the network.

Question 12

Circuit switched networks run over the public switched telephone networks operated by the common carriers.

Question 13

A disadvantage of a star architecture is that the failure of one circuit will disrupt the entire network.

Question 14

One type of ISDN is BRI (basic rate interface).

Question 15

SONET is made up of very high speed dedicated circuits that incorporate inverse multiplexing (IMUX)for all levels above the OC-1 level.

Question 16

An ISDN BRI circuit provides more bandwidth than an ISDN PRI circuit.

Question 17

A T1 circuit provides a data rate of 1.544Mbps.

Question 18

Cloud (as in cloud architecture)means that the design for the common carrier's network comes from satellite networks above the clouds.

Question 19

A dedicated circuit is usually not available late at nights or on weekends.

Question 20

Another way to refer to dialed services is by the term,plain vanilla telephone service (PVTS).

Question 21

Frame relay is a reliable packet service.

Question 22

The _________________ is a Canadian government agency that regulates voice and data communication.

A) PSTN
B) FCC
C) CRTC
D) CSU
E) POTS

Question 23

An intranet VPN connects different organizations over the Internet.

Question 24

An OC-1 circuit provides a data rate of 155 Mbps.

Question 25

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

Question 26

Virtual private networks permit users to create permanent virtual circuits,or tunnels,through the Internet.

Question 27

A ____________ identifies each device connected to an ISDN network terminator.

A) NIC
B) MAC address
C) SPID
D) PRI
E) BRI

Question 28

________ 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

Question 29

ATM can be scaled into faster ATM circuits

Question 30

VPNs offer high security because they operate through the Internet.

Question 31

To connect into a packet switched network,a network terminator is generally used.

Question 32

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

Question 33

Packet switched networks enable packets from separate messages or separate organizations to be interleaved for transmission.

Question 34

MPLS operate at layer 4.

Question 35

Datagrams are connection-oriented.

Question 36

Ethernet/IP packet networks are not provided by common carriers such as AT&T.

Question 37

The committed information rate (CIR)in a permanent virtual circuit is the maximum allowable rate that the network will attempt to provide.

Question 38

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

Question 39

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.

Question 40

____________ 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

Question 41

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

Question 42

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.

Question 43

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

Question 44

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

Question 45

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

Question 46

Which of the following is not a basic architecture for dedicated circuit networks?

A) ring
B) partial mesh
C) bus
D) star
E) full mesh

Question 47

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

Question 48

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

Question 49

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

Question 50

_____ 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

Question 51

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

Question 52

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) mesh design

Question 53

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

Question 54

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-to-point connection directly between each sender and each receiver
E) messages always take one second to travel between sender and receiver

Question 55

In North America,a T1 circuit has ______ 64Kbps channels.

A) 2
B) 30
C) 24
D) 12
E) 36

Question 56

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

Question 57

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

Question 58

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

Question 59

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

Question 60

About ______% of the US population today uses dial-up services.

A) 1
B) 3
C) 5
D) 10
E) 15

Question 61

__________ 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

Question 62

______________ are sometimes called private line services.

A) WANs
B) LANs
C) Circuit-switched networks
D) Dedicated-circuit networks
E) Routed-backbone networks

Question 63

A _______________ is a 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

Question 64

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

Question 65

_____________ is a common standard for use by layer 2 access VPNs for encapsulation.

A) L2TP
B) VPN2
C) Encapsule2
D) TCP/IP
E) PPP

Question 66

_____________ is sometimes called a Layer 2.5 technology.

A) ATM
B) MPLS
C) Ethernet
D) TCP
E) IP

Question 67

With a virtual private network,users create permanent virtual circuits through the Internet called:

A) bursts
B) cells
C) tunnels
D) rings
E) clouds

Question 68

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

Question 69

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

Question 70

The performance of 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

Question 71

Draw a diagram of packet switched service,and describe packet switching concepts.

Question 72

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

Question 73

Using a chart format,list,define and briefly describe two dialed circuit services,three dedicated circuit services,and two packet switched services.

Question 74

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

Question 75

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

Question 76

Which of the following is a primary advantage of a VPN?

A) low cost
B) inflexibility
C) unpredictable traffic congestion
D) security
E) complexity to the user

Question 77

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

Question 78

OC-3072 has a data rate of

A) 159.25 Gbps
B) 39.813 Gbps
C) 1.544 Mbps
D) 100 Mbps
E) 1.244 Gbps

Question 79

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.

Question 80

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