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Exam A QUESTION 1
The exhibit shows a 15454/15216 DWDM system and alarm indications.
What are two possible sources of trouble shown in the system? (Choose two.)
A. fiber failure between sites A and D
B. EDFA failure at site A (clockwise direction)
C. EDFA failure at site C (clockwise direction)
D. 15216 multiplexer at Site A (counter-clockwise direction)
E. OADM pass-through (West “OUT”) failure at site D (clockwise)
F. wavelengths 1 and 3 transmitter failures at site A (clockwise direction)
Correct Answer: AB Section: (none) Explanation
Explanation/Reference:
QUESTION 2
What is the maximum allowable loss budget between the ONS 15216 Mux (left side) composite output and the ONS 15216 Demux (right side) composite input, with the optical values given in the exhibit?
(Assume the worst case loss of 4.5 dB for 15216 200 GHz Mux/Demux and ignore power penalties or extra margin.)
A. 15 dB
B. 17 dB
C. 21 dB
D. 26 dB
E. 27 dB
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 3
What are two important considerations when using 2- or 4-channel 15216 OADMs? (Choose two.)
A. All “Add” channels require uniform power levels.
B. The flexibility of wavelengths per OADM is limited.
C. It is easier to balance “Pass-Through” and “Add” channels.
D. There is a lower pass-through loss using multi-channels OADMs.
E. You can extract a single channel without dropping other channels.
Correct Answer: AE Section: (none) Explanation
Explanation/Reference:
QUESTION 4
What are three relevant design considerations when using the 15216 EDFA? (Choose three.)
A. dispersion
B. Optical SNR
C. span attenuation
D. four wave mixing
E. receiver sensitivity
Correct Answer: BCE Section: (none) Explanation
Explanation/Reference:
QUESTION 5
The ONS 15216 is a 32-channel system. The ONS 15216 OADMs are capable of adding and dropping
one, two, or four channels.
How are the OADMs provisioned to add and drop specific channels?
A. The ONS 15216 OADM can be provisioned to add/drop one, two, or four channels via Cisco Transport Manager (CTM).
B. The ONS 15216 OADM consists only of a four-channel module, and the number of ports utilized determines whether it is a one, two, or four channel OADM.
C. Three separate OADM modules are available for one, two, and four channels. The wavelengths to be dropped and added are programmable via Cisco Transport Manager (CTM).
D. The ONS 15216 OADM consists of only a single-channel module. Two-channel and four-channel support is available by stacking the single-channel module.
E. The ONS 15216 OADM is available in one, two, four channels. There are 32 single-channel OADM modules, 16 two-channel OADM modules, and 8 four-channel OADM modules.
Correct Answer: E Section: (none) Explanation
Explanation/Reference:
QUESTION 6
A 2.5 Gb/s (OC-48 or STM-16) optical signal with a dispersion tolerance of 1200 ps/nm goes through fiber with 18 ps/nm*km of dispersion. How many 15216-DCU-350 equivalents are needed for enough compensation after traveling 100 km?
A. none
B. one
C. two
D. three
E. four
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 7
Given the following parameters: Transmitter output (min): -2 dBm Receiver input (min): -28 dBm 15216 Mux and Demux loss: 4.5 dB 16 channels maximum In which sites shown in the exhibit could the 15216 EDFAs be placed to minimize the number of EDFAs needed?
A. Locations B, C only
B. Locations A, B, C only
C. Locations A, B D only
D. Locations B, C, D only
E. Locations A, B, C D
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 8
A Channel ID mismatch occurs when _____.
A. fibers are terminated incorrectly in a mode
B. the channel number in the received K1 byte is not identical to the channel number transmitted in the K2 byte
C. the channel number in the received C1 byte is not identical to the channel number transmitted in the C2 byte
D. the channel number in the received C2 byte is not identical to the channel number transmitted in the C1 byte
E. the channel number in the received K2 byte is not identical to the channel number transmitted in the K1 byte
Correct Answer: E Section: (none) Explanation
Explanation/Reference:
QUESTION 9
Which timing mode is appropriate for a SONET NE that is adjacent to a SONET NE using BITS-1 timing source?
A. DUS
B. line timing
C. loop timing
D. internal timing
E. through timing
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 10
In order to avoid misconnections due to a failed node in a Bidirectional Line Switched Ring (BLSR), Alarm
Indication Signals (AISs) are sent on every channel normally terminating in that node.
What is the name of this process?
A. trunking
B. squelching
C. nodal bypass
D. bridge and roll
E. node failure insertion
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 11
What protection method is used in 4F BLSR networks?
A. Each fiber has half of its SONET capacity reserved for protection.
B. Two fibers in the span carry working traffic, while the other two fibers in the span are reserved for protection.
C. The signal is sent simultaneously in both directions around the ring. The receiver determines which fiber to listen to based on signal quality.
D. The signal is sent simultaneously in both directions around the ring. The transmitter determined which fiber has the working bit set for the receiver to acknowledge.
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 12
On an ONS 15454 node you can tunnel a(n) _____.
A. SDH circuit over a SONET network delivering it as an SDH signal
B. SDH circuit over a SONET network delivering it as a SONET signal
C. SONET circuit over an SDH network delivering it as an SDH signal
D. SONET circuit over an SDH network delivering it as a SONET signal
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 13
Scrambling of SONET signals is done to _____.
A. prevent the leakage of external fiber emissions
B. provide the optical network with the highest level of security possible
C. assure an even distribution of 1’s and 0’s for extended transmitter life
D. assure an adequate number of transitions for clock recovery at the receiver
E. prevent the receiver from assuming AIS inadvertently when all 0’s are received
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 14
SONET Code Violations (CV’s) totals in the PM tables are actually an accumulation of the number of _____.
A. JO errors detected in a specified interval
B. error detected in a given Errored Second (ES)
C. errors detected in a given Severely Errored second (SES)
D. errors the encryption algorithm detects in a specified interval
E. Bit interleaved Parity (BIP) errors detected in a specified interval
Correct Answer: E Section: (none) Explanation
Explanation/Reference:
QUESTION 15
SONET Path Terminating Equipment (PTE) requires which three line codes to be supported for DS1 and DS3 circuits? (Choose three.)
A. AMI
B. ESF
C. DUS
D. SSM
E. B3ZS
F. B8ZS
Correct Answer: AEF Section: (none) Explanation
Explanation/Reference:
QUESTION 16
How is UPSR and BLSR traffic rerouted during a protection switch when a complete fiber cable cut occurs?
A. Traffic is switched from the first node receiving the AIS indication.
B. Traffic is switched from the far side of the failure, allowing handshake to occur.
C. UPSR traffic is switched from the terminating node, BLSR traffic is rerouted from the originating node in the ring.
D. UPSR traffic is switched from the terminating node, circuit by circuit. BLSR traffic is rerouted from the last reachable node in the ring.
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 17
Which is a legitimate bandwidth matched pair?
A. DS-1;E1
B. DS-1;STM-1
C. OC-3;STM-1
D. STS-1;STM-1
E. OC-192;STM-192
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 18
UPSR protection is initiated by _____, while BLSR is initiated by _____.
A. the K1 SONET byte ; the K2 SONET byte
B. the K2 SONET byte ; the K1 SONET byte
C. transmitter switching ; receiver detection
D. Line Overhead bytes ; Path Overhead bytes
E. Path Overhead bytes ; Line Overhead bytes
Correct Answer: CA Section: (none) Explanation
Explanation/Reference:
UPSR is C. transmitter switching; receiver detection BLSR is
A. the K1 and K2 SONET byte
QUESTION 19
If node 2 is accepting line timing from node 1, node 2 will send _____ to node 1 as its SSM message.
A. ESF
B. PRS
C. DUS
D. SMC
E. B8ZS
Correct Answer: C Section: (none) Explanation
Explanation/Reference: QUESTION 20
DRAG DROP
Match the compatible concepts in SONET and SDH terminology.
A.
B.
C.
D.
Correct Answer: Section: (none) Explanation
Explanation/Reference:
QUESTION 21
Which device creates an OEO conversion?
A. amplifier
B. attenuator
C. regenerator
D. light emitter
E. optical switch
F. optical receiver
G. fiber-optic cable
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 22
What is an advantage of an externally modulated laser over a directly modulated laser?
A. lower cost
B. higher chirp
C. easier to manufacture
D. higher dispersion tolerance
E. higher optical signal-to-noise ratio
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 23
What three in combination are factors that can cause four-wave mixing in fiber-optic cables? (Choose three.)
A. low optical power
B. high optical power
C. few optical channels
D. many optical channels
E. low chromatic dispersion
F. high chromatic dispersion
G. too much power differential in the optical channels
Correct Answer: BCE Section: (none) Explanation
Explanation/Reference:
QUESTION 24
Given the formula:
(Fiber Attenuation * Km) + (Splice Attenuation* # of Splices) + (Connector Attenuation * # of Connectors) +
(Optical Fiber of OADM) + (Buffer (Fiber aging))
A. fiber loss
B. OSNR level
C. post amplification
D. index of reflection
E. index of refraction
F. power post amplification budget
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 25
DRAG DROP
Match the component to its description.
A.
B.
C.
D.
Correct Answer: Section: (none) Explanation
Explanation/Reference:
QUESTION 26
What is the difference between the transmitted power and the sensitivity of the receiver?
A. OSNR
B. dispersion
C. attenuation
D. power budget
E. amplifier spacing
F. four wave mixing
Correct Answer: D Section: (none) Explanation
Explanation/Reference: QUESTION 27
What is the phenomenon called where different wavelengths of light travel at different speeds?
A. OSNR
B. dispersion
C. light skew
D. attenuation
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 28
Why are the 1300 nm and 1550 nm regions of the fiber spectrum primarily used for optical communications?
A. They are both regions of lowest loss.
B. They are both regions of low reflections.
C. They are both regions of low index of refraction.
D. They are both regions of low chromatic dispersion.
E. They are both regions of low Polarization Mode Dispersion (PMD).
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
QUESTION 29
Which three technologies are used to reduce chromatic dispersion accumulation in fiber-optic transmission systems? (Choose three.)
A. PIN photodiodes
B. zero-chirped lasers
C. Erbium-doped fiber amplifiers
D. dispersion compensating fiber
E. dispersion compensating Bragg grating
Correct Answer: BDE Section: (none) Explanation
Explanation/Reference:
QUESTION 30
DRAG DROP
Match the appropriate term to each formula.
A.
B.
C.
D.
Correct Answer: Section: (none) Explanation
Explanation/Reference:
QUESTION 31
If the power is 0 dBm, what is the power in mW?
A. 0 mW
B. 1 mW
C. 10 mW
D. 1.5 mW
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 32
For lasers with tightly controlled wavelengths, approximately how far apart are the centers of adjacent wavelengths when 100 GHz spacing is used in a DWDM system?
A. 0.4 nanometers
B. 0.6 nanometers
C. 0.8 nanometers
D. 1.2 nanometers
E. 1.6 nanometers
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 33
How is a Thin Film filter fabricated?
A. The glass core is doped with an Erbium in periodic segments of the fiber.
B. Layers of high index “H” and low level “L” material are deposited on a glass substrate.
C. Thin layers of silica glass are placed onto wafers to produce a prism-like effect.
D. Fiber is etched with an ultraviolet laser that is precisely spaced for specific wavelength filtering.
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 34
The dispersion of a non-zero dispersion shifted fiber is 6 ps/nm*km at 1550 nm and 10 ps/nm* km at 1610
nm.
What is the minimum dispersion compensation required if an L-Band DWDM signal travels through 200 km
of fiber and has a dispersion tolerance of 1800 ps/nm?
A. none
B. -600 ps/nm
C. -200 ps/nm
D. +200 ps/nm
E. +600 ps/nm
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 35
Exhibit:
When designing a DWDM system with multiple amplified spans, a pre-amp is needed at Site B to _____. (Choose three.)
A. offset the OADM loss at Site B
B. overcome the high multiplexer loss at Site A
C. amplify signal levels after the high loss through Fiber Span 1
D. adjust add channels at Site B to be at the same level as the passthrough channels
E. ensure that the per channel power is higher than the minimum needed for the post-amp at Site B
Correct Answer: ACE Section: (none) Explanation
Explanation/Reference:
QUESTION 36
If the dispersion of a given fiber is 17 ps/nm*km at 1550 nm and zero at 1310 nm, then what is the accumulated dispersion of an ITU wavelength after it travels 200 km?
A. 0 ps/nm
B. 340 ps/nm
C. 200 ps/nm
D. 3400 ps/nm
E. More information is needed.
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 37
What are three factors that limit the maximum distance of an amplified optical signal without regeneration?
A. fiber dispersion
B. signal attenuation
C. transmitter power
D. amplifier bandwidth
E. receiver dispersion tolerance
Correct Answer: ABD Section: (none) Explanation
Explanation/Reference:
QUESTION 38
Exhibit:
Which type of multiplexer is shown in the exhibit?
A. Thin Film filter
B. Fiber Bragg Grating
C. Arrayed Wave Guide
D. Erbium fiber amplifier
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
QUESTION 39
In the OSNR model for EDFA amplifiers, SNROUT = 1/(1SNRIN + FhvB/PIN), what does SNRIN represent?
A. the signal to noise of the current optical amplifier
B. the signal to noise of the previous amplifier or source
C. the signal to noise introduced by the optical multiplexer
D. the accumulated noise to signal ratio of the optical channel
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
QUESTION 40
A customer wants to create a 1:1 protection group with a DS3N-12 card. Which card slots would allow for a
1:1
protection?
A.
Slot 2 and Slot 4
B.
Slot 4 and Slot 6
C.
Slot 5 or Slot 13 only
D.
Slot 16 and Slot 17
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 41
Exhbit:
Within an ONS 15454, you are provisioning a circuit on an unprotected UPSR ring. In the exhibit, which two must you configure? (Choose two.)
A. revertive
B. circuit type
C. circuit size
D. bidirectional
E. protected drops
F. switch on PDI-P
Correct Answer: BC Section: (none) Explanation
Explanation/Reference:
QUESTION 42
You are provisioning a DS-1 circuit on an ONS 15454 UPSR configuration and XC-10G card. How many total VT ports are used within the VT matrix at the source node?
B. 1
C. 2
D. 3
E. 4
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 43
You are provisioning a DS-1 circuit on an ONS 15454 2F-BLSR with a XC-10G card. Each VT 1.5 connection must also terminate via the STS matrix. On the originating circuit node, how many STS ports are now available for VT 1.5 circuits?
A. 2
B. 3
C. 4
D. 20
E. 22
F. 24
Correct Answer: E Section: (none) Explanation
Explanation/Reference:
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