Final 2009 (24 Questions)
1. Which layer is immediately below the Network layer? a. Physical
b. Network c. Transport d. data link layer
Nice Hint: OSI layers 1. all-application 2. people-presentation 3. should-session 4. try-transport 5. new-network 6. Diet -data link 7. Pepsi-physical
2. The communication protocol which is used to achieve communication between agents and managers is ___________.
a. TCP b. FTP c. CCNP d. CMIP
3. For simplifying network management, the ITU standards have divided the management domain into __________ layers.
a. Two b. Three c. Four d. Five
4. ___________ is that part of a network element which provides a home within the telecommunication system for the agent that will manage the network element. a. Reference function block b. Mediation function block
c. Q adaptor function block d. Network element function block
5. The tree arrangement in the figure below shows how timing is distributed from the primary reference clock (PRC) to a series of slave clocks. This is an example of ____________.
a. Inter-station synchronization b. Intra-station synchronization c. Ultra-station synchronization d. Multi-station synchronization
6. One second period that contains 30% or more of errored blocks is called ________. a. Highly errored second b. Severely errored second
c. Large errored second d. Huge errored second
7. The main role of the ____________ is to determine whether a request from the PC’s operating system is for local or remote resource.
a. NetBIOS b. TCP/IP protocol stack
c. Server Message Block d. Redirector
8. In network environment, providing a reliable service is the main concern of _____________.
a. Internet protocol b. Transmission control protocol c. Universal datagram protocol d. Ethernet protocol
9. Which of the following is the error-detection and correction method?
a. Parity b. Hamming code c. Checksum checking d. Cyclic redundancy checking 10. Which type of error detection uses binary division?
a. Parity b. Longitudinal redundancy checking
c. Checksum checking d. Cyclic redundancy checking
11. The solution to the problem of scalability of the Internet is to break the network down into manageable parts, or domains each called ____________.
12. for a CSMA/CD network, twice the propagation time between the two most distant stations is called _________________.
a. Transfer time b.slot time c. Round trip delay time d.Both b and c 13. When a network interface has a failure in its circuitry, it sends a continuous stream of
frames causing the Ethernet LAN to enter a Collapse state. This condition is known as __________.
a. Scattering b.Jabbering c.Blocking d.Refreshing
14. In an object-oriented model, when different classes have operations with the same name but different implementation, they are having the property of ___________.
a. Inheritance b.Association c.Polymorphism d.Aggregation
15. Ethernet, point to point protocols are examples of protocols that are used in ____________________.
a. Application layer of OSI reference model b.Presentation layer of OSI reference model c. Session layer of OSI reference model d.Data link layer of OSI reference model
16. Session control, file and printer are three categories of messages which pass requests and acknowledgements in a client-server platform. They are used by __________________. a. SMB protocol b.TCP/IP protocol c.Ethernet protocol d.CSMA/CD protocol
17. ____________________ is a technique which transforms an analogue telephone circuit into a digital signal, and involves three consecutive processes: sampling, quantization and encoding.
a. Pulse Code Modulation (PCM) b.Frequency Modulation (FM) c.Amplitude Modulation (AM) d.Phase Modulation (PM)
18. The frame alignment word is a sequence of bits that allows the start of each STM-1 frame to be clearly identified within SDH network. It is contained within _________________. a. Regenerator section overhead b.Multiplex section overhead
c. Synchronous section overhead d.Sequence section overhead
19. the failure density function, f (t) is used to give the probability of failure during an interval of time. It is known as ______________.
a. Cumulative probability distribution b.Probability density distribution c. Cumulative density distribution d. Normal probability distribution
20. _______________ is one of the Telecommunication management network (TMN) functional blocks that will convert TMN information into a format that can be easily understood by the user.
a. Operations system function block b.Workstation function block c. Reference function block d..Network element function block
21. In Telecommunication management Network (TMN) system, the role of the manager is to issue commands and requests to the agent. These commands and requests are known as ________________.
a. Notifications b.Feedbacks c.Operations d.Acknowledgements
22. The sequence of the binary digits representing the outcomes of parity checks in Hamming codes is known as _________________.
a. Look-up entry b.Hamming distance c.Radix d.Syndrome 23. Rather than sending the absolute value of each sample, it is possible to achieve a smaller
transmission bit-rate by sending the difference between consecutive samples. This is known as _______________.
a.Delta modulation b.Delta–sigma modulation c.Adaptive delta modulation d.Differential PCM
24. One of the compression techniques in communication uses the fact that in most pictures, there is considerable correlation between neighboring areas that is a high degree of redundancy in the data to compress. This type of compression is known as _____________.
a. Temporal compression b. Spatial compression c. Dynamic compression d. Random compression Final 2008 (20 questions)
1. Fourier theorem states that any periodic signal can be thought of as a sum of a number of ______________ of different amplitudes, frequencies and phases.
a) square waves b)sine waves c) sawtooth waves d)triangular waves 2. The equation that represents the cosine waveform is:
a) y = 2 cos 1000 π t b) y = 2 cos 2000 π t c) y = 2 cos 3000 π t d) y = 2 cos 4000 π t
3. The routing of packets among nodes within an autonomous system is carried out by the routers using a protocol called _______________.
a) border gateway protocol (BGP) b)interior gateway protocol (IGP) b) internet protocol d )autonomous system protocol
4. In order to avoid spread data too widely across a LAN, a _________ is used in a star topology. This device directs traffic by acting intelligently upon address information contained within the header of every packet it receives.
a) bridge b)hub c)repeater d)carrier sense
5. ___________ or block-diagram equivalent circuits are used throughout engineering to represent the behavior and structure of systems.
a) Signal sequence diagrams b)State transition tables
c)State transition diagrams d)Models
6. A class is a collection of same-type objects. For example, a model of a graphical user interface will contain several different ‘window’ objects. The individual window objects are said to be ___________ of the window class.
a) subclasses b)parent classes c)super-classes d)instances
7. An object contains a collection of data items relating to a particular component of the system called ____________.
a) operations b)attributes c)services d)methods
8. The ___________ of the OSI reference model is concerned with the transmission of the raw bit-stream and will have to deal with all necessary interfacing to send and receive that bit-stream over the physical medium.
a) transport layer b)network layer c)data link layer d)physical layer
9. User datagram protocol (UDP) is a _____________ protocol for use with applications that do not need sequencing and flow control.
10. The pulse code modulation PCM is a technique which transforms an analogue telephone circuit into a digital signal, and involves three consecutive processes called
__________________.
a) sampling, quantization and justification b)sampling, quantization and encoding c) sampling, encoding and justification d)quantization, encoding and justification
11. In PDH the variation in timing, between the tributaries, is handled by a process called _____________ which can add extra bits to match the bit-rate of each tributary to the aggregate bit-rate.
a) plesiochronous b)sunchronization c)quantization d)justification
12. _______________ is a term used to describe the phase variation (in the time domain) of a digital signal from its normal, or ideal, time position
a) Wander b)Buffer c)Jitter d)Reference signal
13. The _______________ is the probability that a component will survive to time t. a) failure function b)reliability function
c)failure density function d)reliability density function
14. In managing SDH networks, all the stages that are necessary in deciding where, when and how a ring should be installed can be classed as _____________ process.
a) managing b)performance c)planning d)configuration
15. Once in service, the responsibility falls to the ___________ to monitor network elements to detect alarms and other performance indicators defined in the information model.
a) configuration manager b)accounting manager
c)Security manager d)performance manager
16. The agent is ______________ which can handle many objects in a particular network element. All functions carried out by the network element must be presented to the agent using object descriptions as defined by managed objects. The capability to manage telecommunication equipment from many different manufacturers is very important to TMN
a) a managed object b)an open system c)a manager d)a network element 17. The ___________ is a characteristic of the source, representing the average amount of
information it provides. This is independent of how symbols from the source are coded. a) efficiency b)memory c)probability d)entropy
18. A code word can be translated as soon as it arrives so we say that the code is __________________.
a) variable length code b)uniquely decodable c) instantaneously decodable d)efficient code
19. There are three main types of coding used in digital telecommunications called ________________.
a)message, channel, and error coding b)message, error, and line coding
Final 2007 (30 questions)
2. What does flow control determine?
a. When a device can transmit b. Whether a device is connection oriented or connectionless
c. Both a and b d. Neither a nor b
1. Which layer is immediately below the data link layer? a. Physical
b. Network c. Transport d. Application
Nice Hint: OSI layers 1. all-application 2. people-presentation 3. should-session 4. try-transport 5. new-network 6. Diet -data link 7. Pepsi-physical
3. Converting data into signals by transforming and encoding the information to produce electromagnetic signals is the functionality of a ___________.
a. source b.transmitter c.receiver d.destination
4. Which of the following describes stop-and-wait flow control?
a. It is simple b. It is complex
c. It is best with small frames d. It is best over long distances
5. What must a sender do before a receiver’s sliding windows buffer can expand? a. Send an acknowledgment b. Receive an acknowledgment
c. Either a or b d. Neither a nor b
6. Controlled access line discipline is used with which type of circuit?
a. Point-to-point b. Multipoint c. Either a or b d. Neither a nor b 7. Which of the following is the simplest error-detection method?
a. Parity b. Longitudinal redundancy checking
c. Checksum checking d. Cyclic redundancy checking 9. Which of the following is also called forward error correction?
a. Simplex b. Retransmission
c. Detection-error coding d. Error-correction coding
13. The IEEE 802.3 specification divides the data link layer into two sub-layers: the Logical link control sub-layer and the medium access control sub-layer. An example of one implementation of medium access control is _______________.
a. TCP protocol b.CSMA/CD protocol c.IP protocol d.UDP protocol
15. Telnet, FTP, SMTP, DNS, HTTP are examples of protocols that are used in ____________________.
a.application layer of OSI reference model b. presentation layer of OSI reference model c. session layer of OSI reference model d. data link layer of OSI reference model
Note: here are two question repeated in 2009 + 2007 with different answer. most probably Synchronous section overhead is correct.
18. The frame alignment word is a sequence of bits that allows the start of each STM-1 frame to be clearly identified within SDH network. It is contained within _________________. a.Regenerator section overhead b.Multiplex section overhead
c.Synchronous section overhead d.Sequence section overhead
18. The frame alignment word is a sequence of bits that allows the start of each STM-1 frame to be clearly identified within SDH network. It is contained within _________________. a. Regenerator section overhead b.Multiplex section overhead
19. The Star arrangement in the figure below shows how it is used to distribute the timing source within a telecommunication station in SDH network. This is an example of ___________________.
a. Intra-station synchronization b.Inter-station synchronization
c. Ultra-station synchronization d.Multi-station synchronization
20. ____________ is the standard defined by the American National Standard Authority, ANSI T1 for synchronous operation used in North America.
a.DXC b.STM-1 c.ADM d.SONET
26. The electron beam in the cathode ray tube (CRT) inside the TV set is made to scan the whole visible surface of the screen in a zigzag pattern. This is known as ____________.
a. raster b.picture line c.frame d.broadcast
27. The figure below shows an example of a modulation system used in digital communication. What is that modulation system?
a. PCM Modulation. b.Delta Modulation. c. Sigma Modulation. d.Differential Modulation.
29. Reversible or lossless coding is a type of coding for which the exact data can be recovered after decoding. This type of coding is used by _________________.
a. PCM encoding b.Huffman encoding c.Run-length encoding d.Both b and c 30. The error represented by the difference between the original and quantized signals set a
fundamental limitation to the performance of PCM systems known as __________________.
a. dynamic range b. quantization noise c. detection-error d. correction-error Final 2006 (30 questions)
1) The solution to the problem of of the Internet is to break the network down into manageable parts, or domains each called Autonomous System.
a) high cost b) scalability c) interfaces d) different protocols
2) The routing of packets among nodes within Autonomous System is carried out by the routers using a protocol called .
a)IGP b)BGP c)EGP d)PGP
3) Routing between Autonomous Systems uses a different protocol called a _.
a)IGP b) BGP c)EGP d)PGP
4) In an object-oriented model, one special type of relationship that exists between objects is when one object is part of another. This is called .
a) multiplicity b)aggregation c) containment d) both b and c 6) Source and destination port numbers, and sequence and acknowledge numbers are
main fields that are defined inside .
a) a TCP segment b) an IP segment c) an Ethernet segment d)a MAC segment 7) In an attempt to improve the email service, a new protocol has been proposed as an extension for SMTP. This protocol is known as .
a) ESMTP b) MIME c) MOME d) MITP
8) In network environment, providing a reliable service is the main concern of _. a) internet protocol b) transmission control protocol
c) universal datagram protocol D)Ethernet protocol 10) A key principle for digital transmission is _.
a) serial synchronization b) frequency synchronization c) frame synchronization d) multiplexing synchronization
11) The figure below is an example of a time division multiplexing process that is based on .
a) bit-interleaving b) byte-interleaving c)octet-interleaving d) word-interleaving 15) The reliability function, R (t), and failure function, Q (t) that give the probability of something happening up to specified time are known as .
a) probability density distribution b) cumulative probability distribution c) cumulative density distribution d) normal probability distribution
16) is that part of a network element which provides a home within the telecommunication system for the agent that will manage the network element.
a) Q adaptor function block b) Mediation function block
c) Reference function block d) Network element function block
18) In telecommunication management network (TMN) system, the agent replies to the manager commands are known as _.
a) operations b) feedbacks c) notifications d) acknowledges
20) For a communication system, the number of symbols used in the code alphabet is known as
21) The Shannon’s noiseless coding theorem is based on _.
a) Shannon’s first theorem b) Shannon’s second theorem c) Shannon’s third theorem d) Shannon’s fourth theorem
22) In a communication system, the failure of the reconstructed signal to follow the original one is known as .
a) falling construction b)falling slope c)overload failure d) slope overload 23) The main reason for adding headers in each layer of OSI model is .
a) to identify which application is used b) to identify performance and speed c) to provide control information on how to handle data/packets
d) to show the user the order of responsibility of each layer
24) is used to ensure that the sender does not overwhelm the receiver. a) Data control b) Send control c) Receive control d) Flow control
25) For a message of 50 frames using stop-and-wait flow control, acknowledgments would be returned to the sender.
a) none b) 1 c) 50 d) medium dependable
27) data link protocol uses start and stop bits.
a) Asynchronous b) Synchronous c) Full duplex d) Simplex 28) A point-to-point circuit can be .
a) half-duplex b) full-duplex c) either a or b d) neither a nor b
29) At layer, physical addressing occur.
a) physical b) data link c) network d) application
30) A sender must before a sender’s sliding windows buffer can expand. a) send an acknowledgment b) receive an acknowledgment
c) either a or b d) neither a nor
1- Which of the following is a reversible or lossless compression technique? a- Hamming encoding
b- Huffman encoding c- Run-length encoding
d- Both b and c
2- Which layer of the OSI model is responsible for the routing of packets in a network?
a- Network layer
b- Physical layer c- Transport layer d- Data link layer
3- The minimum sampling rate is called? a- Data rate
b- Symbol rate
c- Nyquist rate
4- The maximum signaling rate which can be transmitted along a channel is numerically equal to ______________.
a- Twice the channel bandwidth
b- The cchannel bit-rate
c- The channel bandwidth d- Three times channel 5- MPEG stands for _________.
a- Multi Picture Expert Group
b- Moving Picture Expert Group
c- Motion Picture Expert Group d- None of the above
6- Which of the following is not a part of the channel coding? a- Rectangular code
b- Checksum checking c- Hamming code
d- Huffman code
7- The number of digits by which any two binary sequences differ is called the _______. a- Hamming weight
b- Hamming distance
c- Hamming code d- Hamming length
8- The ___________ is concerned with the transmission of the raw bit-stream. a- Network layer of the OSI model
b- Physical layer of the OSI model
c- Session layer of the OSI model d- Date link layer of the OSI model
9- The number of symbols in the code alphabet is known as the radix of the code, so a binary code has radix __________.
a- Radix 2
b- Radix 3 c- Radix 4
d- None of the above
10- The frequency of occurrence of an event may be expressed as a fraction of the total number of events. This is called a _________.
a- Frequency reference
b- Relative frequency
c- Conditional probability d- None of the above
11- The IEEE 802.11 WLAN specification divides the data link layer, into two sub-layers; the Logical link control sub-layer and the medium access control sub-layer. An example of one implementation of medium access control is __________.
a- UDP protocol b- Ethernet protocol
c- CSMA/CA protocol
12- SDH uses ___________ to measure block errors. a- CRC
b- Rectangular code
c- Bit-interleaved parity (BIP)
d- Simple parity check 13-
The management carried out by a TMN is called ___________. a- Telecommunication management
b- Remote management
c- Information management
d- None of the above
14- A technique used is speech coding to achieve a smaller dynamic range in quantization levels sends only the difference between consecutive samples. This technique is known as
____________. a- PCM modulation
b- Delta modulation
c- Random delta modulation d- On- off keying
15- CMIP in TMN stands for:
a- Communication management information protocol
b- Common management information protocol
c- Common management interface protocol d- None of the above
16- What is that modulation used in system in the figure a below?
a- Direct Modulation
b- Delta Modulation
c- DPCM Modulation d- On-Off Modulation
17- The way the agent sends information to the manager in a TMN is via ________.
a- Notification
b- Instruction c- Operations
18- One of the compression techniques in MPEG uses the fact that in most pictures, there is considerable correlation between consecutive frames. This type of compression is known as ____________. a- Temporal compression b- Dynamic compression c- Spatial compression d- Random compression Question 1
A has-a relationship is implemented via : Choose one answer.
a. Inheritance b. Composition c. All of the above d. None of the above Question 2
The _____________ occupies all the payload area (9x261) plus row four of the overhead in STM-1.
Choose one answer.
a. AU-4
b. VC-4 c. TU
d. VC-12 Question3
In Telecommunication management Network (TMN) system, the role of the manager is to issue commands and requests to the agent. These commands and requests are known as
________________. Choose one answer. a. notifications b. feedbacks c. operations
d. acknowledgements
Question 4
A 155.52 Mbit/s link connects two networks, as shown in the figure below. The timing of the received STM-1 varies by STM-10-11 from the clock in the adjacent network. What is the time interval between byte slips?
Choose one answer.
a. 155.52 *106 bits received in 1 second.
A variation of 10-11 will result in a bit slip in every 1011 bits.
1011/155.52*106=643 seconds
b. 155.52 *106 bits received in 1 second.
A variation of 10-11 will result in a bit slip in every 1011 bits.
155.52*106/1011=0.0015552 seconds
c. none of the answers is correctly calculated as 155.52 *10not 1 second. 6 bits are received in 1 minute and
Question 5
In PCM, 8 bits are used to encode each sample, and the sampling rate is 8KHz, or 8000 times per second. Hence the bit-rate for one encoded speech signal is :
Choose one answer.
a. 8 * 8000 = 64 kbit/s b. 8 / 8 = 1 kbit/s c. 8 * 80 = 640 bit/s
d. 8 * 84 = 32 kbit/s
Question 6
__________________ is the external world of the system Choose one answer.
a. Process b. Signal
c. Environment d. Instance
Question 7
A continuous power spectrum is known as Choose one answer.
a. a power density spectrum.
b. a power spectrum. c. a power fixed spectrum. d. a power light spectrum
Question 8
Which layer is immediately below the data link layer? Choose one answer.
a. Physical b. Network c. Transport d. Application Question 9
When a station detects collision, it immediately stops transmission of the frame. It then calculates a delay using ____________________ algorithm to restart transmission.
Choose one answer. a. Exponential
b. Exponential backoff c. Slot time
d. All of the choices Question 10
General definition of slot time with repeaters is Choose one answer.
a. Propagation delay + delay at repeaters b. Only propagation delay
c. Only delay at repeaters
d. Twice the (propagation delay + delay at repeaters)
Question 11
Containers in payload area of the STM-1 have extra overhead bytes added to them to become: Choose one answer.
a. virtual containers
b. overhead c. tributary unit d. pointers
Question 12
A quantity of 100 components all fail within one year of service. 5 components failed during the first month, 15 components have failed within 2 months. Which statement is untrue?
Choose one answer.
a. The probability of failure that one component fails within two months F(2)=0.15 b. The probability of failure that 15 components fail within two months F(2)=0.15 c. The reliability of the individual components for two months service R(2)=0.85 d. The cumulative failure also called the failure density in the first month is f(2)=0.05 Question 13
Order the following figures in terms of their total reliability, smallest first is:
a. 2, 1, 3
b. 1, 3, 2 c. 1, 2, 3
d. b and c are equal
Question 14
Which of the following management layers have been identified for use within TMN? Choos e all that apply.
Choose at least one answer. a. performance management b. planning management c. network management d. configuration management e. accounting management f. service management g. security management h. forecast management Question 15
____________________ is a term used to describe the phase variation (in the time domain) of a digital signal from its normal, or ideal, time position.
Choose one answer.
a. jitter
b. wander c. train pulse Question 16
________________ allows a number of signals that have a relatively small bandwidth to share a medium that has a much larger bandwidth.
Choose one answer.
a. Frequency division multiplexing
b. pulse code modulation
c. plesiochronous digital hierarchy d. standardization
Question 17
The failure density function, f(t) is used to give the probability of failure during an interval of time. It is known as ______________.
Choose one answer.
a. Probability density distribution
b. Cumulative probability distribution c. Cumulative density distribution d. Failure probability distribution
Question 18
The data in a class are also called: Choose one answer.
a. attributes.
b. instance variables. c. fields.
d. all of the above Question 19
For a __________________________system , it is possible to predict its future behavior from the knowledge of its current condition and input signals.
Choose one answer. a. State machine b. Deterministic c. Non-deterministic d. stochastic Question 20 A Repeater is
Choose one answer.
a. A frame forwarding device inside one collision domain b. A bit-forwarding device inside one collision domain
c. An IP packet forwarding device inside one collision domain Question 21
Marks: 1
For a CSMA/CD network, twice the propagation time between the two most distant stations is called _________________.
Choose one answer. a. slot time
b. transfer time
c. round trip delay time d. both a and c
Question22
ISP stands for ______________. Choose one answer.
a. International Service protocol b. Internet Service provider c. Internet System protocol d. International Systems protocol
Question 23
Logical Link Control and Medium Access Control are sub-layers __________________. Choose one answer.
a. Physical Layer b. Data link layer c. Network layer d. Transport layer Question 24
Which language is used by the International Telecommunication Union (ITU) for describing telecommunication systems:
Choose one answer. a. Java
b. Smalltalk c. SDL
d. All of the above Question 25
How are four STM-1 signals formed to make an STM-4? Choose one answer.
a. they are formed using byte-interleaving b. they are formed using synochronization c. they are formed using multiplexing Question 26
MTBF is
Choose one answer.
a. a basic measure of reliability for non-repairable items b. a basic measure of reliability for identical items c. a basic measure of reliability for non-identical items d. a basic measure of reliability for repairable items Question 27
On a network during the day , 40% of the sent packets are lost , and 60% are received. What is the probability that 2 out of the next three packets will be lost?
Choose one answer. a. 0.67
b. 0.28 c. 0.52 d. 0.9
Question 28
_____________ provide a general architecture for the transport of management data within the TMN.
Choose one answer. a. computer programs b. Functional blocks c. Management layers d. Objects
Question 29
Calculate the block size for one frame of VC-4? Choose one answer.
a. 261 columns*9 rows*8(bits in a byte)=18792 bits.
b. 270 columns*9 rows*8(bits in a byte)=19440 bits. c. 261 columns*9 rows=2349 bits.
Question 30
List the steps that an analogue speech signal goes through to become a PCM signal. Choose one answer.
a. sampling, quantization, encoding and appending. b. sampling, encoding and appending.
c. quantization, sampling and appending. d. encoding and decoding.
Question31
The tree arrangement in the figure below shows how timing is distributed from the primary reference clock (PRC) to a series of slave clocks. This is an example of ____________.
Choose one answer.
a. Inter-station synchronization b. Intra-station synchronization c. Ultra-station synchronization d. Multi-station synchronization
Question 32
Subclass constructors can call super class constructors via the keyword: Choose one answer.
a. super b. this
c. none of the above
Question 33
Modulation can be used for : Choose one answer.
a. both analogue signals and digital signals b. analogue signals
c. digital signals None of the above Question 34
A MAC address is Choose one answer.
a. The address of the machine, given by a system administrator b. The serial number of the Ethernet adapter
c. The IP address given by NetBios Question 35
Original Ethernet is Choose one answer.
a. Shared medium, one collision domain per LAN b. Point to point links, one collision domain per LAN c. Point to point links, several collision domains per LAN Question 36
For a CSMA/CD network, twice the propagation time between the two most distant stations is called _________________________.
Choose one answer. a. Jam time
b. Message delay c. Slot time
d. Exponential backoff time
Question 37
Internet is an example of __________________. Choose all that apply.
Choose at least one answer.
a. Circuit Switched Network
b. Datagram Network c. Packet Switched Network d. None of the above
Question 38
In a one-to-one relationship how many instance(s) of each class takes part in the relationship: Choose one answer.
a. none
b. One or more c. Only one
d. All of the above Question 39
The ____________ in STM-1 frame is used to locate the start of the VC-4 which unlike the AU-4 does not have a fixed position within the STM-1.
Choose one answer. a. pointer address b. overhead address c. VC-1 d. VC-12 e. TU Question 40
If a component has a failure rate of 2 failures per million hours, the MTBF is: Choose one answer.
a. 200,000 hours b. 500,00 hours c. 500,000 hours d. 1000,000 hours Question 41
If A and B are disjoint, then P( A OR B) = Choose one answer.
a. P( A) + P( B) - P(AB) b. P( A) + P( B)
c. P(AB)
Question 42
Which of the following management layers have been identified for use within TMN? Choos e all that apply.
Choose at least one answer. a. performance management b. planning management c. network management d. configuration management e. accounting management f. service management g. security management h. forecast management Question 43
A PDH network could have provided a similar capacity as the STM-1 in figure below, using 140 Mbit/s line system. If we have to “add/drop” 2Mbits PDH paths at ADMs how many multiplexers we would need?
Choose one answer. a. 2/8, 8/34 and 34/140 b. 2/34, 8/140 and 34/140 c. 2/8, 34/140 and 8/140 Question 44
_________________ is the range contained between the lowest and highest frequency. Choose one answer.
a. frequency b. bandwidth c. multiplexing d. standardization
Question 45
The failure density function, f(t) is used to give the probability of failure during an interval of time. It is known as ______________.
a. Probability density distribution b. Cumulative probability distribution c. Cumulative density distribution d. Failure probability distribution Question 46
Object Oriented Programming is characterized by using: a. encapsulation.
b. inheritance. c. polymorphism.
d. all of the above. Question 47
One special type of relationship when one object is part of another is known as: a. Polymorphism b. Multiplicity c. Aggregation/containment d. Specialization Question 48
This is graph of a sinewave with frequency :
a. 1/3 kHz b. 3 kHz c. 6 kHz d. 3 Hz Question 49 A Repeater is
a. A frame forwarding device inside one collision domain b. A bit-forwarding device inside one collision domain
c. An IP packet forwarding device inside one collision domain Question 50
A system that allows several cables to be part of the same collision domain is a. A bridge
b. A repeater c. A router
Question 51
What is the most commonly used LAN technology today? a. Ethernet
b. Fast Ethernet c. Gigabit Ethernet d. 10 gigabit Ethernet Question 52
What are the reasons for evolution of fast Ethernet and gigabit Ethernet? a. All the options are correct
b. Increase in the number of users
c. Bandwidth hungry applications such as multimedia d. Demand for high data rates
Question 53
In a one-to-one relationship how many instance(s) of each class takes part in the relationship: Choose one answer.
a. none
b. One or more c. Only one
d. All of the above
Question 54
Given that each frame is made up of a 270 by 9 blocks of bytes, and one frame is transmitted in 125µs, calculate the bit-rate of the STM-1 signal.
Choose one answer.
a. 270*9*8/125*10-6=155.52 Mbits/s
b. 270*9*8/125*10=15.552 Mbits/s c. 270*9*8/125=155.52 bits/s
Question 55
Two exchanges, each with availability A = 0.980, are linked by three parallel routes, each with availability 0.99, what is the availability of the system?
Choose one answer.
a. 0.912 b. 0.991 c. 0.872 d. 0.959 Question 56
The gives the probability of failure during: Choose one answer.
a. time interval when both components fail b. a small time interval
c. a long time interval d. total failure
Question 57
_____________ provide a general architecture for the transport of management data within the TMN.
Choose one answer.
a. computer programs b. Functional blocks c. Management layers d. Objects
Question 58
A PDH network could have provided a similar capacity as the STM-1 in figure below, using 140 Mbit/s line system. If we have to “add/drop” 2Mbits PDH paths at ADMs how many multiplexers we would need?
Choose one answer.
a. 2/8, 8/34 and 34/140 b. 2/34, 8/140 and 34/140 c. 2/8, 34/140 and 8/140 Question 59
What is the bit-rate of the primary signal if each frame contains 32 bytes, and each frame is constructed in 125µs ?
Choose one answer.
a. 32*8/125*10-6=2048 kbits/s
b. 32*16/125*10-6=32768 kbits/s
c. 32*16/125*8-6=12768 kbits/s
Question 60
The tree arrangement in the figure below shows how timing is distributed from the primary reference clock (PRC) to a series of slave clocks. This is an example of ____________.
Choose one answer.
a. Inter-station synchronization b. Intra-station synchronization c. Ultra-station synchronization d. Multi-station synchronization Question 61 An object is:
Choose one answer.
a. one instance of a class. b. another word for a class. c. a class with static methods.
d. a method that accesses class attributes. Question 62
For a __________________________system , it is possible to predict its future behavior from the knowledge of its current condition and input signals.
Choose one answer.
a. State machine b. Deterministic c. Non-deterministic d. stochastic
Question 63
__________ has a constant power spectral density for all frequencies as shown below.
Choose one answer.
a. Noise
b. White noise c. Power density d. Frequency Question 64
Using bridging we can have Choose one answer.
a. Several collision domains per LAN b. One collision domain per LAN c. Several LANs per collision domain Question 65
Which layer is immediately below the Network layer? Choose one answer.
a. Physical b. Network c. Transport d. data link layer
Question 66
Different types of signals or many signals are combined using device called __________________. Choose one answer.
a. Router b. Multiplexer c. Switch d. Antenna Question 67
For a CSMA/CD network, twice the propagation time between the two most distant stations is called _________________________.
Choose one answer.
a. Jam time b. Message delay c. Slot time
