Chapter 12 - Wide Area Networks

Question 1

WANs connect nodes, such as workstations, servers, printers, and other devices, in a small geographical area on a single network

Answer 1

False

Question 2

In a frame relay WAN, the ISP typically has the data circuit terminating equipment (DCE)

Answer 2

True

Question 3

An 802.11ac signal can travel for approximately 2 miles from the source

Answer 3

False

Question 4

In a public switched telephone network, lines are terminated at the central office.

Answer 4

True

Question 5

DSL signals travel over telephone lines using the 300 to 3300 Hz frequency range.

Answer 5

False

Question 6

DSL services require many subscribers to share the same local line, causing potential security concerns

Answer 6

False

Question 7

Although MPLS can operate over Ethernet frames, it is more often used with other Layer 2 protocols, like those designed for WANs.

Answer 7

True

Question 8

Most satellites circle the Earth 22,300 miles above the equator in a geosynchronous orbit

Answer 8

True

Question 9

CDMA (Code Division Multiple Access) is an open standard that is accepted and used worldwide

Answer 9

False

Question 10

The word “synchronous” as used in the name of Synchronous Optical Network means that data being transmitted and received by nodes must conform to a timing scheme.

Answer 10

True

Question 11

What is the maximum throughput of a DS3 connection?

Answer 11

44.736 Mbps

Question 12

Multiplexing enables a single T1 circuit to carry how many channels?

Answer 12

24

Question 13

In an ISDN connection, what amount of throughput did a single B channel provide?

Answer 13

64 Kbps

Question 14

What is the size of an ATM cell, including the header?

Answer 14

53 bytes

Question 15

Which of the following is an advantage of leasing a frame relay circuit over leasing a dedicated circuit?

Answer 15

You pay only for the bandwidth you require.

Question 16

Of all the DSL standards, which is the most commonly in use today?

Answer 16

ADSL

Question 17

The DTE or endpoint device for a leased line is known as which device below?

Answer 17

CSU/DSU

Question 18

What OC level is primarily used as a regional ISP backbone, and occasionally by very large hospitals, universities, or other major enterprises?

Answer 18

OC-48

Question 19

The C-Band utilized by satellites consists of what frequency range?

Answer 19

3.4 - 6.7 GHz

Question 20

In metro settings, end-to-end, carrier-grade Ethernet networks can be established via what protocol?

Answer 20

Carrier Ethernet Transport

Question 21

Which statement regarding the use of cable modems is NOT accurate?

Answer 21

Cable modems only operate at the Physical layer of the OSI model.

Question 22

The T-carrier standards, also called T-CXR standards, utilize what type of multiplexing over two wire pairs to create multiple channels?

Answer 22

time division multiplexing (TDM)

Question 23

On an ATM network, how is the path that data will take determined?

Answer 23

Switches determine the optimal path between sender and receiver, and then establish the path before transmission.

Question 24

What type of virtual circuit allows connections to be established when parties need to transmit, then terminated after the transmission is complete?

Answer 24

switched virtual circuit (SVC)

Question 25

Which of the following Layer 1 WAN technologies is not normally used as last mile service, but rather traverses multiple ISP networks, connecting these networks to the Internet backbone?

Answer 25

SONET (Synchronous Optical Network)

Question 26

Where are MPLS labels placed within a frame?

Answer 26

between the layer 2 header and the layer 3 header

Question 27

What is a data-link connection identifier (DLCI) utilized for?

Answer 27

It is used by routers to determine which circuit to forward a frame to in a frame relay network.

Question 28

Which statement regarding the Asynchronous Transfer Mode (ATM) technology is accurate?

Answer 28

ATM can provide 4 levels of QoS, from best effort delivery to guaranteed, real-time transmission.

Question 29

The Global System for Mobile Communications (GSM) utilizes what technology to create timeslots on a channel?

Answer 29

time division multiple access (TDMA)

Question 30

When using satellite services for your WAN connection, what statement is accurate?

Answer 30

Satellite services suffer more latency and jitter issues.

Question 31

Considering that multiple users occupy the same channel when using CDMA, how are various calls using this technology kept separate?

Answer 31

The packets are coded such that individual calls can be distinguished.

Question 32

Which SONET OC level is a popular choice for large businesses, and is equivalent to 100 T1s?

Answer 32

OC-3

Question 33

With a SIP trunk, what is the only limitation on the number of calls that can run at any one time?

Answer 33

The amount of available bandwidth.

Question 34

In North America, what ISDN connection type used two B channels and one D channel?

Answer 34

Basic Rate Interface (BRI)

Question 35

In a public switched telephone network, what portion of the network is known as the local loop?

Answer 35

It is the portion that connects any residence or business to the nearest central office.

Question 36

Which type of DSL technology has equal download and upload speeds maxing out at around 2 Mbps?

Answer 36

SDSL

Question 37

When using DOCSIS 3.0, what is the minimum number of channels that can be used?

Answer 37

4

Question 38

A fractional T1’s bandwidth can be leased multiples of what data rate?

Answer 38

64 Kbps

Question 39

In a cellular network, where does each wireless base station connect to?

Answer 39

They connect to a mobile switching center.

Question 40

How many transponders are contained within a typical satellite?

Answer 40

24 to 32