1. How many digits of the DNIC (Data Network Identification Code) identify the country?
A. first three
B. first four
C. first five
D. first six
E. None of the above
Answer: A
2. A station in a network forwards incoming packets by placing them on its shortest output queue. What routing algorithm is being used?
A. hot potato routing
B. flooding
C. static routing
D. delta routing
E. None of the above
Answer: A
3. The probability that a single bit will be in error on a typical public telephone line using 4800 bps modem is 10 to the power -3. If no error detection mechanism is used, the residual error rate for a communication line using 9-bit frames is approximately equal to
A. 0.003
B. 0.009
C. 0.991
D. 0.999
E. None of the above
Answer: B
4. Frames from one LAN can be transmitted to another LAN via the device
A. Router
B. Bridge
C. Repeater
D. Modem
Answer: B
5. Which of the following condition is used to transmit two packets over a medium at the same time?
A. Contention
B. Collision
C. Synchronous
D. Asynchronous
E. None of the above
Answer: B
6. You have a class A network address 10.0.0.0 with 40 subnets, but are required to add 60 new subnets very soon. You would like to still allow for the largest possible number of host IDs per subnet. Which subnet mask should you assign?
A. 255.240.0.0
B. 255.248.0.0
C. 255.252.0.0
D. 255.254.0.0
E. 255.255.255.255
Answer: D
7. What are the most commonly used transmission speeds in BPS used in data communication?
A. 300
B. 1200
C. 2400
D. 9600
E. None of the above
Answer: D
8. What is the default subnet mask for a class C network?
A. 127.0.0.1
B. 255.0.0.0
C. 255.255.0.0
D. 255.255.255.0
E. None of the above
Answer: D
9. Which of the following is used for modulation and demodulation?
A. modem
B. protocols
C. gateway
D. multiplexer
E. None of the above
Answer: A
10. Which of the following is not a disadvantage of wireless LAN?
A. Slower data transmission
B. higher error rate
C. interference of transmissions from different computers
D. All of the above
Answer: D
11. The Internet Control Message Protocol (ICMP)
A. allows gateways to send error a control messages to other gateways or hosts
B. provides communication between the Internet Protocol Software on one machine and the Internet Protocol Software on another
C. reports error conditions to the original source, the source must relate errors to individual application programs and take action to correct the problem
D. All of the above
E. None of the above
Answer: D
12. Your company has a LAN in its downtown office and has now set up a LAN in the manufacturing plant in the suburbs. To enable everyone to share data and resources between the two LANs, what type of device(s) are needed to connect them? Choose the most correct answer.
A. Modem
B. Cable
C. Hub
D. Router
Answer: D
13. The term 'duplex' refers to the ability of the data receiving stations to echo back a confirming message to the sender. In full duplex data transmission, both the sender and the receiver
A. cannot talk at once
B. can receive and send data simultaneously
C. can send or receive data one at a time
D. can do one way data transmission only
E. None of the above
Answer: B
14. How many hosts are attached to each of the local area networks at your site?
A. 128
B. 254
C. 256
D. 64
E. None of the above
Answer: B
15. Which of the following technique is used for fragment?
A. a technique used in best-effort delivery systems to avoid endlessly looping packets
B. a technique used by protocols in which a lower level protocol accepts a message from a higher level protocol and places it in the data portion of the low level frame
C. one of the pieces that results when an IP gateway divides an IP datagram into smaller pieces for transmission across a network that cannot handle the original datagram size
D. All of the above
E. None of the above
Answer: C
16. Contention is
A. One or more conductors that serve as a common connection for a related group of devices
B. a continuous frequency capable of being modulated or impressed with a second signal
C. the condition when two or more stations attempt to use the same channel at the same time
D. a collection of interconnected functional units that provides a data communications service among stations attached to the network
E. None of the above
Answer: C
17. Avalanche photodiode receivers can detect hits of transmitted data by receiving
A. 100 photons
B. 200 photons
C. 300 photons
D. 400 photons
E. None of the above
Answer: B
18. Satellite-Switched Time-Division Multiple Access (SS/TDMA) is
A. the method of determining which device has access to the transmission medium at any time.
B. a medium access control technique for multiple access transmission media
C. a form of TDMA in which circuit switching is used to dynamically change the channel assignments
D. All of the above
E. None of the above
Answer: C
19. When you ping the loopback address, a packet is sent where?
A. On the network
B. Down through the layers of the IP architecture and then up the layers again
C. Across the wire
D. through the loopback dongle
E. None of the above
Answer: B
20. Which of the following TCP/IP protocol is used for transferring electronic mail messages from one machine to another?
A. FTP
B. SNMP
C. SMTP
D. RPC
E. None of the above
Answer: C
21. Which of the following device is used to connect two systems, especially if the systems use different protocols?
A. hub
B. bridge
C. gateway
D. repeater
E. None of the above
Answer: C
22. The synchronous modems are more costly than the asynchronous modems because
A. they produce large volume of data
B. they contain clock recovery circuits
C. they transmit the data with stop and start bits.
D. they operate with a larger bandwidth
E. None of the above
Answer: B
23. A distributed network configuration in which all data/information pass through a central computer is
A. bus network
B. star network
C. ring network
D. Point-to-point network
E. None of the above
Answer: B
24. Which of the following TCP/IP protocol allows an application program on one machine to send a datagram to an application program on another machine?
A. UDP
B. VMTP
C. X.25
D. SMTP
E. None of the above
Answer: A
25. A remote batch-processing operation in which data is solely input to a central computer would require a:
A. telegraph line
B. simplex lines
C. mixed-band channel
D. All the above
E. None of the above
Answer: B
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