question

false

answer

(T/F) 1. In a star topology, a single connection failure will halt all traffic between all sites.

question

true

answer

(T/F) 2. Dial-up ISDN does not convert a computer's digital signals to analog before transmitting them over the PSTN.

question

true

answer

(T/F) 3. ATM is a WAN technology that functions in the Data Link layer.

question

true

answer

(T/F) 4. SONET specifies framing and multiplexing techniques at the Physical layer.

question

false

answer

(T/F) 5. After SONET, BPL has the best maximum throughput available.

question

publicly

answer

1. WANs typically send data over ____ available communications networks.

question

WAN sites

answer

2. The individual geographic locations connected by a WAN are known as ____.

question

nonroutable

answer

3. Because WAN connections require routers or other Layer 3 devices to connect locations, their links are not capable of carrying ____ protocols.

question

redundant

answer

4. On most modern WANs, a ring topology relies on ____ rings to carry data.

question

mesh

answer

5. ____ WANs are the most fault-tolerant type of WAN because they provide multiple routes for data to follow between any two points.

question

PSTN (public switched telephone network)

answer

6. The ____ encompasses the entire telephone system, from the wires that enter homes and businesses to the network centers that connect different regions of a country.

question

CO (central office)

answer

7. A(n) ____ is the place where a telephone company terminates lines and switches calls between different locations.

question

dial-up

answer

8. A ____ connection is one in which a user connects her computer, via a modem, to a distant network and stays connected for a finite period of time.

question

local loop/last mile

answer

9. The portion of the PSTN that connects any residence or business to the nearest CO is known as the ____.

question

FTTH (fiber to the home)

answer

10. ____ means that a telephone company connects residential users to its network with fiber-optic cable.

question

frame relay

answer

11. ____ is an updated, digital version of X.25 that also relies on packet switching.

question

bonding

answer

12. In a process called ____, two 64-Kbps ISDN B channels can be combined to achieve an effective throughput of 128 Kbps.

question

(TA) terminal adapter

answer

13. A ____ converts digital signals into analog signals for use with ISDN phones and other analog devices.

question

23

answer

14. ISDN PRI uses ____ B channels and one 64-Kbps D channel.

question

signal

answer

15. The speed of a T-carrier depends on its ____ level.

question

smart jack

answer

16. At the customer's demarcation point, either inside or outside the building, RJ-48 connectors terminate in a ____.

question

DSLAM (DSL access multiplexer)

answer

17. A ____ aggregates multiple DSL subscriber lines and connects them to the carrier's CO.

question

security

answer

18. Broadband cable requires many subscribers to share the same local line, thus raising concerns about ____ and actual (versus theoretical) throughput.

question

fixed packet

answer

19. What sets ATM apart from Ethernet is its ____ size.

question

fault tolerant

answer

20. SONET's extraordinary ____ results from its use of a double-ring topology over fiber-optic cable.

question

OC (optical carrier)

answer

21. The data rate of a particular SONET ring is indicated by its ____, a rating that is internationally recognized by networking professionals and standards organizations.

question

virtual circuits

answer

1. ____________________ are connections between network nodes that, although based on potentially disparate physical links, logically appear to be direct, dedicated links between those nodes.

question

T-carrier

answer

2. A(n) ____________________ uses TDM (time division multiplexing) over two wire to divide a single channel into multiple channels.

question

receiving

answer

3. A(n) ____________________ node in synchronous communications recognizes that it should be receiving data by looking at the time on the clock.

question

multiplexer

answer

4. A(n) ____________________ combines individual SONET signals on the transmitting end, and another multiplexer separates combined signals on the receiving end.

question

LANE (LAN emulation)

answer

5. ____________________ encapsulates incoming Ethernet or token ring frames, then converts them into ATM cells for transmission over an ATM network.

question

tiered topology

answer

1. Contain sites that are connected in star or ring formations are interconnected at different levels, with the interconnection points being organized into layers to form hierarchical groupings.

question

downstream

answer

2. Occurs when data travels from the carrier's switching facility to the customer.

question

star topology

answer

3. Contains a single site acting as the central connection point for several other points.

question

asymmetrical communications

answer

4. Occurs when downstream throughput is higher than upstream throughput.

question

signal level

answer

5. Refers to the T-carrier's Physical layer electrical signaling characteristics as defined by ANSI standards in the early 1980s.

question

upstream

answer

6. Occurs when data travels from the customer to the carrier's switching facility.

question

bus topology

answer

7. Occurs when each site is directly connected to no more than two other sites in a serial fashion.

question

symmetrical technology

answer

8. Provides equal capacity for data traveling both upstream and downstream.

question

mesh topology

answer

9. Incorporates many directly interconnected sites.

question

--enable communication between clients and hosts for resource sharing. --same protocols from Layers 3 and higher --carry digitized data via packet-switched connections.

answer

1. Describe the fundamental properties WANs and LANs have in common.

question

The network of lines and carrier equipment that provides telephone service to most homes and businesses with digital transmission.

answer

2. Define and describe a PSTN.

question

X.25 is analog and frame relay is digital.

answer

3. Describe an important difference between frame relay and X.25.

question

An arrangement that allows a customer to lease only some of the channels on a T1 line. They may expect their traffic to grow and that may require a full T1 eventually, but can't currently justify leasing a full T1.

answer

4. Define a fractional T1 and explain why an organization might implement it.

question

The term xDSL refers to all DSL varieties. -ADSL -G.Lite -HDSL -SHDSL -SDSL -VDSL

answer

5. Define the term xDSL and name the better known DSL varieties.

question

modulates and demodulates signals via cable. operate at physical and data link layer. connects to PC via RJ-45/USB/wireless or a switch/router.

answer

6. Explain how a cable modem is utilized in broadband cable connections.

question

it helps ATM maintain point-to-point connection-oriented transmissions

answer

7. Explain how ATM relies on virtual circuits.

question

-can integrate other WAN technologies // can work with different signal types and standards -offers fast data transfer rates //fiber-optics, determined by OC level -allows for simple link additions/removals //multiplexer -provides high degree of fault tolerance //double-ring topology over fiber-optic cable

answer

8. List and describe the key strengths of SONET.

question

interoperability between different signal types and standards

answer

9. Describe the most important advantage of SONET.

question

high cost

answer

10. Why is SONET technology typically not implemented by small or medium-size businesses?

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