Chapter 16 - Wide Area Networks

Question 1

Which of the following is not a WAN protocol or technology?

A. ATM

B. ISDN

C. MPLS

D. RIP

Answer 1

1. D. Routing Information Protocol (RIP) is not a WAN protocol but a routing protocol used in internetworks.

Question 2

What OSI model layers do WAN protocols operate in?

A. Layer 6, Layer 4, Layer 2

B. Transport, Data Link, Network

C. Physical, Data Link, Network

D. Application, Data Link, Network

Answer 2

2. C. These different protocols and technologies all occupy the lower three layers of the OSI model: the Physical layer, the Data Link layer, and sometimes the Network layer. Most WAN protocols work only at the Physical layer and Data Link layer.

Question 3

If you have a device in a telecommunications closet owned and installed by the telecommunications company (telco) and it’s your responsibility to cable from this box to the CPE, which term should you use to refer to the device?

A. Customer premises equipment

B. Demarcation point

C. Toll network

D. Central office

Answer 3

3. B. The demarcation point is the precise spot where the service provider’s responsibility ends and the CPE begins.

Question 4

You have an E1. How many DS0s are used in this point-to-point connection?

A. 24

B. 25

C. 30

D. 32

Answer 4

4. D. The European version of the T1 is the E1, which operates at 2.048 Mbps and uses 30 64 Kbps channels (30 DS0s), and two channels are used for D channels, which makes 32total DS0s.

Question 5

Where does the local exchange carrier responsibility end and your responsibility begin on a WAN link?

A. POP

B. Central office

C. Demarc

D. Smart jack

Answer 5

5. C. The demarc is the precise spot where the service provider’s (local exchange carrier’s) responsibility ends and the CPE begins. It’s generally a device in a telecommunications closet owned and installed by the telecommunications company (telco).

Question 6

You have a small office, home office environment. What WAN technology would most likely be used?

A. T1

B. T3

C. Frame Relay

D. Cable modem

Answer 6

6. D. Cable is a great cost-effective connection for a small office or home office (SOHO).

Question 7

Which type of communication has a line speed of 1.544 Mbps (millions of bits per second)?

A. T3

B. T1C

C. T1

D. T4

Answer 7

7. C. A T1 has a line speed of 1.544 Mbps. This 1.544 Mbps connection uses Digital Signal 1 (DS1) and aggregates 24 discrete 64 Kbps channels that use Digital Signal 0 (DS0). Other T-series connections have greater maximum connection speeds.

Question 8

Which cellular WAN technology has the best data rate?

A. HSPA

B. HSPA+

C. LTE

D. WiMAX

Answer 8

8. C. LTE is true 4G and has the best data rates.

Question 9

Which is not a common optical carrier level (OC-x)?

A. OC-1

B. OC-4

C. OC-12

D. OC-192

Answer 9

9. B. OC-1, OC-3, OC-12, OC-48, and OC-192 are the normal service offerings. OC-1 has the lowest data rate at 51.84 Mbps, and OC-192 is the highest at 9.953 Gbps.

Question 10

Which wireless protocol utilizes a short-range communications technology facilitating data transmission from fixed and/or mobile devices, creating wireless personal area networks (PANs)?

A. Bluetooth

B. Microwave radio relay

C. Comsat

D. Point-to-multipoint

Answer 10

10. A. Bluetooth uses a radio technology called Frequency Hopping Spread Spectrum. It chops up the data being sent and transmits chunks of it through the air on up to 75 different frequencies.

Question 11

What does the x in xDSL represent?

A. Wire type

B. Transmission speed

C. DSL type

D. Download speed

Answer 11

11. C. The x in xDSL represents the different letters that refer to the DSL flavors. xDSLs use high-frequency signals, whereas regular phone calls use low-frequency signals over the same lines.

Question 12

Which is not a type of xDSL?

A. ADSL

B. HDSL

C. SONET

D. SDSL

Answer 12

12. C. ADSL, HDSL, SDSL, VDSL or VHDSL, and VDSL2 are all common xDSL types. Synchronous Optical Network (SONET) is the standard for synchronous data transmission on optical fiber.

Question 13

What does the acronym DOCSIS stand for?

A. Data over cable service interface spectrum

B. Data over cable systems Internet specification

C. Data over cable service Internet specification

D. Data over cable service interface specifications

Answer 13

13. D. DOCSIS stands for data over cable service Interface Specifications. All cable modems and like devices have to measure up to this standard.

Question 14

What is the bandwidth for OC-12?

A. 1.544 Mbps

B. 45 Mbps

C. 622 Mbps

D. 1000 Mbps

Answer 14

14. C. Optical carrier 12 has speeds up to 622 Mbps.

Question 15

Which WAN protocol utilizes cell-switching technology?

A. Frame Relay

B. ISDN

C. ATM

D. RIP

Answer 15

15. C. ATM uses a high-speed cell-switching technology that can handle data as well as real-time voice and video. The ATM protocol breaks up transmitted data into 53-byte cells.

Question 16

Which WAN protocol utilizes packet-switched technology?

A. Frame Relay

B. ISDN

C. ATM

D. RIP

Answer 16

16. A. Frame Relay is the frame WAN technology in which variable-length packets are transmitted by switching.

Question 17

What is the CIR in Frame Relay?

A. Virtual circuit that is established when data needs to be transmitted

B. Maximum speed at which the Frame Relay interface can transmit

C. Rate at which the Frame Relay switch guarantees to transfer data

D. Rate at which the Frame Relay switch agrees to receive data

Answer 17

17. C. The committed information rate (CIR) is the rate, in bits per second, at which the Frame Relay switch guarantees to transfer data.

Question 18

You are having DSL Internet connection issues and time-outs. You check the interface on your router and notice a lot of input errors. What could the problem be?

A. CSU/DSU

B. Demarc

C. Duplex configuration

D. Clocking is down

Answer 18

18. C. We’re thinking in terms of a DSL, so a CSU/DSU is not used, nor is a demarc. If clocking was down, your Internet would be completely down. Input errors could be indicative of a duplex issue.

Question 19

Which part of a SIP trunk is the responsibility of the provider?

A. Private domain

B. Community domain

C. Public domain

D. External domain

Answer 19

19. C. The public domain (responsibility of the provider) is the part of the network that allows access into the PSTN (Public Switched Telephone Network) or PLMN (Public Land Mobile Network).

Question 20

Which technology can eliminate VPN traffic between remote sites traversing the hub?

A. DMVPN

B. SIP trunk

C. DMDW

D. DNSSEC

Answer 20

20. A. Benefits of Dynamic Multipoint VPN include elimination of traffic between remote sites traversing the hub, elimination of additional bandwidth requirements at the hub, elimination of additional network delays, conservation of WAN bandwidth, lower costs for VPN circuits, and increased resiliency and redundancy.

Question 21

Passive Optical Network (PON), also called fiber to the premises, is a new option for connecting homes and business to the Internet.

Answer 21

Common optical carrier levels (OC-x)
Level Data rate
OC-1 51.84 Mbps
OC-3 155.52 Mbps
OC-12 622.08 Mbps
OC-48 2.488 Gbps
OC-192 9.953 Gbps
OC-768 39.813 Gbps