Computer Networks Questions & Answers – Access Networks

 TECH PKPRAJAPAT

TECH PKPRAJAPAT

Computer Networks Questions & Answers – Access Networks

 

1. Which of this is not a constituent of residential telephone line?

a) A high-speed downstream channel

b) A medium-speed downstream channel

c) A low-speed downstream channel

d) An ultra-high speed downstream channel

View Answer

 

Answer: c

Explanation: A low-speed downstream channel is not a constituent of a residential telephone line. But it might be just a two-way telephone channel. Internet can be provided through a high-speed downstream channel in a residential telephone line.

 

2. DSL telcos provide which of the following services?

a) Wired phone access

b) ISP

c) Wired phone access and ISP

d) Network routing and ISP

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Answer: c

Explanation: DSL stands for Digital Subscriber Line and ISP stands for Internet Service Provider. In a Digital Subscriber Line system, the same company which provides phone connection is also an ISP. The internet is provided through the pre-installed telephone lines.

 

3. The function of DSLAM is to __________

a) Convert analog signals into digital signals

b) Convert digital signals into analog signals

c) Amplify digital signals

d) De-amplify digital signals

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Answer: a

Explanation: DSLAM stands for Digital Subscriber Line Access Multiplexer and it’s used by Telcos to convert the analog signals to digital signals for the purpose of providing internet. The DSLAM located in a telco’s Central Office does this function.

 

4. Which of the following terms is not associated with DSL?

a) DSLAM

b) CO

c) Splitter

d) CMTS

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Answer: d

Explanation: CMTS stands for Cable modem termination system. It is used in cable internet access. In cable internet access, internet is not provided through telephone lines and the companies that provide such connections don’t necessarily provide telephone access.

 

5. HFC contains _______

a) Fibre cable

b) Coaxial cable

c) A combination of Fibre cable and Coaxial cable

d) Twisted Pair Cable

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Answer: c

Explanation: Hybrid fiber-coaxial (HFC) is a telecommunications industry term for a broadband network that combines optical fiber and coaxial cable. It has been popularly used since the early 1990s. It is stronger than the optical fiber cables and faster than the co-axial cables.

6. Which of the following statements is not applicable for cable internet access?

a) It is a shared broadcast medium

b) It includes HFCs

c) Cable modem connects home PC to Ethernet port

d) Analog signal is converted to digital signal in DSLAM

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Answer: d

Explanation: CMTS stands for Cable modem termination system. In cable access analog signal is converted to digital signal by CMTS. In cable internet access, internet is not provided through telephone lines. DSLAM is used by Telecom companies.

7. Among the optical-distribution architectures that are essentially switched ethernet is __________

a) AON

b) PON

c) NON

d) MON

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Answer:a

Explanation: AON stands for Active optical networks which are essentially switched Ethernets. Each user has his/her own dedicated optical fiber line connecting to the ISP in an AON.

8. StarBand provides __________

a) FTTH internet access

b) Cable access

c) Telephone access

d) Satellite access

View Answer

 

Answer: d

Explanation: StarBand was a two-way satellite broadband Internet service available in the U.S. from 2000–2015. It was discontinued from September 30 2015 due to increasing competition from other ISPs.

9. Home Access is provided by __________

a) DSL

b) FTTP

c) Cable

d) All of the mentioned

View Answer

 

Answer: d

Explanation: Home Internet Access is provided by DSL, FTTP, and Cable. FTTP provides the fastest speeds followed by the cable connections and then the DSLs. FTTP is popularly used in modern connections.

10. ONT is connected to splitter using _________

a) High speed fibre cable

b) HFC

c) Optical cable

d) Twisted pair cable

 

Answer: c

Explanation: ONT stands for Optical Network Terminal. The ONT connects to the Termination Point (TP) with an optical fibre cable. It translates light signals from the fibre optic line to electric signals that the router can read.

 

11. Which of the following factors affect transmission rate in DSL?

a) The gauge of the twisted-pair line

b) Degree of electrical interfernece

c) Shadow fading

d) The gauge of the twisted-pair line and degree of electrical interference

 

Answer: d

Explanation: Because DSL is made of twisted wire copper pair, the gauge of twisted pair line i.e. the protection and electrical interference would affect the transmission rate in DSL. Unlike DSL, FTTP is not really affected by these factors.