This document contains a quiz on SONET (Synchronous Optical Networking) concepts with multiple choice questions and answers. It tests knowledge of technical details like SONET frame durations, network topologies, signal hierarchies, and components like multiplexers, regenerators and add/drop multiplexers.

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