Basic Some Useful Mcqs About Sonet

1. Choose the letter of the best answer in each questions.
1. In SONET each frame lasts _______ microseconds.
• A) 20
• B) 64
• C) 125
• D) none of the above
2. A linear SONET network can be __________.
• A) multipoint
• B) point-to-point
• C) either (a) or (b)
• D) neither (a) nor (b)
3. The path overhead consists of ______ bytes.
• A) 18
• B) 9
• C) 6
• D) 1
4. _______ is a standard developed by ITU-T.
• A) SONET
• B) SDH
• C) either (a) or (b)
• D) neither (a) nor (b)
5. A ______ is the portion of the network between two multiplexers.
• A) line
• B) path
• C) section
• D) none of the above
6. A ________ is a repeater.
• A) ADM
• B) regenerator

2. • C) STS multiplexer/demultiplexer
• D) none of the above
7. The ______ layer is responsible for the movement of a signal across a physical section.
• A) path
• B) section
• C) photonic
• D) line
8. In ______ APS, there is one working line and one protection line. The data are normally sent on the
working line until it fails.
• A) one-to-one
• B) one-plus-one
• C) one-to-many
• D) none of the above
9. Line overhead consists of ________ bytes.
• A) 18
• B) 9
• C) 6
• D) 1
10. In SONET, for each frame, the bytes are transmitted __________.
• A) from left to the right, bottom to top
• B) from left to the right, top to bottom
• C) from right to the left, top to bottom
• D) from right to the left, bottom to top
11. Each ________in a SONET frame can carry a digitized voice channel.
• A) frame
• B) bit
• C) byte
• D) none of the above
12. An STS-1 frame is made ______columns.

3. • A) 90
• B) 9
• C) 1
• D) none of the above
13. The ______ layer is responsible for the movement of a signal from its optical source to its optical
destination.
• A) line
• B) path
• C) photonic
• D) section
14. The ____ layer is responsible for the movement of a signal across a physical line.
• A) line
• B) path
• C) photonic
• D) section
15. An STS multiplexer is a ______ device.
• A) four-layer
• B) three-layer
• C) two-layer
• D) one-layer
16. A ring SONET network can be _________.
• A) bidirectional
• B) unidirectional
• C) either (a) or (b)
• D) neither (a) nor (b)
17. _______ is a standard developed by ANSI for fiber-optic networks.
• A) SDH
• B) SONET
• C) either (a) or (b)
• D) neither (a) nor (b)

4. 18. An add/drop multiplexer is a ______ device.
• A) four-layer
• B) three-layer
• C) two-layer
• D) one-layer
19. In SONET, for each byte, the bits are transmitted ____________.
• A) from most significant to the least significant
• B) from least significant to the most significant
• C) three at a time
• D) two at a time
20. A _______ is the optical link connecting two neighbor devices.
• A) path
• B) line
• C) section
• D) none of the above
21. A ______is the end-to-end portion of the network between two STS multiplexers.
• A) line
• B) path
• C) section
• D) none of the above
22. The _______ layer corresponds to the physical layer of the OSI model.
• A) photonic
• B) path
• C) line
• D) section
23. SONET is a _______ TDM system.
• A) statistical
• B) asynchronous
• C) synchronous
• D) none of the above

5. 24. An STS-3 frame is made of ______ rows.
• A) 27
• B) 9
• C) 1
• D) none of the above
25. SONET defines _______ layers.
• A) five
• B) four
• C) three
• D) two
26. In ________ APS, there are normally two lines: one working line and one protection line. Both lines
are active all the time.
• A) one-to-one
• B) one-to-many
• C) one-plus-one
• D) none of the above
27. __________ allow insertion and extraction of signals.
• A) STS multiplexer/demultiplexers
• B) regenerators
• C) ADMs
• D) none of the above
28. An STS-3 frame is made of ________ columns.
• A) 270
• B) 90
• C) 9
• D) none of the above
29. SONET has defined a hierarchy of signals called ________.
• A) STMs
• B) STSs
• C) either (a) or (b)

6. • D) neither (a) nor (b)
30. An ______ signal is the optical modulation of an STS-n (or STM-n) signal.
• A) FDM-n
• B) OC-n
• C) TDM-n
• D) none of the above
31. A regenerator is a ________ device.
• A) three-layer
• B) one-layer
• C) two-layer
• D) four-layer
32. An STS-1 frame is made of ________ rows
• A) 90
• B) 9
• C) 1
• D) none of the above
33. SDH has defined a hierarchy of signals called ________.
• A) STMs
• B) STSs
• C) either (a) or (b)
• D) neither (a) nor (b)
34. To make SONET backward-compatible with the current hierarchy, its frame design includes a system
of ____.
• A) VTs
• B) STSs
• C) STMs
• D) OCs
35. SONET network topologies can be __________.
• A) ring
• B) mesh

7. • C) linear
• D) all of the above
36. SONET sends ________ frames per second.
• A) 8000
• B) 4000
• C) 2000
• D) 1000
37. A SONET system can use _________.
• A) regenerators
• B) add/drop multiplexers
• C) STS multiplexers
• D) all of the above
38. In ________APS, there is only one protection line for many working lines. When a failure occurs in
one of the working lines, the protection line takes control until the failed line is repaired.
• A) one-to-one
• B) one-plus-one
• C) one-to-many
• D) none of the above
39. The section overhead consists of ______octets.
• A) 18
• B) 9
• C) 6
• D) 1