NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
What is one reason why broadband cable operators install fiber-
optic cable in stages instead of changing the infrastructure all at
once? -
correct answer ✅Changing the infrastructure all at once would
cause too many service disruptions
What is the difference between the fiber-to-the-node (FTTN) and
fiber-to-the-curb (FTTC) topologies? -
correct answer ✅An FTTC is allowed a smaller number of RF
amplifiers between the optical fiber and the customer premises.
Which of these components is used in a passive optical network
(PON)? -
correct answer ✅Optical splitters
Which type of star topology used in a passive optical network (PON)
places the PON splitters into fiber access terminal (FAT) located
deep in the network and closer to the customer premises than the
centralized split? -
correct answer ✅Distributed star
,NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
Which element of a passive optical network (PON) uses a Bragg
grating filter? -
correct answer ✅Optical distribution network (ODN)
What is it about radio frequency over glass (RFoG) that made
broadband cable operators envision using it to make a seamless
transition from the legacy hybrid fiber/coax (HFC) architecture over
to a gigabit-capable passive optical network (GPON) or Ethernet
passive optical network (EPON)? -
correct answer ✅RFoG can operate in parallel with GPON or EPON,
which eliminates the need for any downtime during the transition
How are optical splitters used in the forward path? -
correct answer ✅In the forward path, optical splitters are used as
passive branching devices that divide an optical signal across
multiple output fibers.
Which of the following describes a fiber pigtail? -
correct answer ✅Fiber-optic cable with pre-connectorized ends.
Heat shrink tubing is installed over the fusion-splice to strengthen
and protect it. When should the heat shrink be installed on the
fiber? -
,NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
correct answer ✅Before stripping the plastic coating from the
fiber.
Which Data over Cable Service Interface Specification (DOCSIS)
layer is used by the cable modem termination system (CMTS) to
differentiate between cable modems? -
correct answer ✅The DOCSIS Media Access Control (MAC) Layer.
What was introduced in Data Over Cable Service Interface
Specification (DOCSIS) 3.0 to allow enough bandwidth for upstream
carriers from previous DOCSIS versions? -
correct answer ✅The option to increase the top frequency of the
upstream to 85 MHz
In a Data Over Cable Service Interface Specification (DOCSIS)
network, why is the data throughput over the return or upstream
path typically less than the throughput of data over the forward or
downstream path? -
correct answer ✅Compared to the downstream path, the
narrower bandwidths and lower orders of modulation used to
transport data over the return path cause the downstream and
upstream data throughput to be unequal or asymmetrical.
, NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
What would be the downstream throughput if two quadrature
amplitude modulation (QAM) channels with a throughput of 38
megabits per second (Mbps) were bonded? -
correct answer ✅76 Mbps
What are two features that were added in Data Over Cable Service
Interface Specification (DOCSIS) 3.1 to extend the viability of hybrid
fiber/coax (HFC) networks into the next decade? -
correct answer ✅Orthogonal frequency division multiplexing
(OFDM) and low-density parity-check (LDPC)
How does Internet protocol (IP) multicast differ from IP broadcast? -
correct answer ✅IP multicast traffic is only sent to specific modem
addresses on the network; IP broadcast traffic is sent to all modems
on the network
Which step in the troubleshooting process requires a discussion
with the customer to gather more detail about the problem? -
correct answer ✅Step 1: Identify the problem.
When analyzing a problem, what can the technician learn by asking
the customer to show or demonstrate the problem? -
AND ANSWERS
What is one reason why broadband cable operators install fiber-
optic cable in stages instead of changing the infrastructure all at
once? -
correct answer ✅Changing the infrastructure all at once would
cause too many service disruptions
What is the difference between the fiber-to-the-node (FTTN) and
fiber-to-the-curb (FTTC) topologies? -
correct answer ✅An FTTC is allowed a smaller number of RF
amplifiers between the optical fiber and the customer premises.
Which of these components is used in a passive optical network
(PON)? -
correct answer ✅Optical splitters
Which type of star topology used in a passive optical network (PON)
places the PON splitters into fiber access terminal (FAT) located
deep in the network and closer to the customer premises than the
centralized split? -
correct answer ✅Distributed star
,NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
Which element of a passive optical network (PON) uses a Bragg
grating filter? -
correct answer ✅Optical distribution network (ODN)
What is it about radio frequency over glass (RFoG) that made
broadband cable operators envision using it to make a seamless
transition from the legacy hybrid fiber/coax (HFC) architecture over
to a gigabit-capable passive optical network (GPON) or Ethernet
passive optical network (EPON)? -
correct answer ✅RFoG can operate in parallel with GPON or EPON,
which eliminates the need for any downtime during the transition
How are optical splitters used in the forward path? -
correct answer ✅In the forward path, optical splitters are used as
passive branching devices that divide an optical signal across
multiple output fibers.
Which of the following describes a fiber pigtail? -
correct answer ✅Fiber-optic cable with pre-connectorized ends.
Heat shrink tubing is installed over the fusion-splice to strengthen
and protect it. When should the heat shrink be installed on the
fiber? -
,NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
correct answer ✅Before stripping the plastic coating from the
fiber.
Which Data over Cable Service Interface Specification (DOCSIS)
layer is used by the cable modem termination system (CMTS) to
differentiate between cable modems? -
correct answer ✅The DOCSIS Media Access Control (MAC) Layer.
What was introduced in Data Over Cable Service Interface
Specification (DOCSIS) 3.0 to allow enough bandwidth for upstream
carriers from previous DOCSIS versions? -
correct answer ✅The option to increase the top frequency of the
upstream to 85 MHz
In a Data Over Cable Service Interface Specification (DOCSIS)
network, why is the data throughput over the return or upstream
path typically less than the throughput of data over the forward or
downstream path? -
correct answer ✅Compared to the downstream path, the
narrower bandwidths and lower orders of modulation used to
transport data over the return path cause the downstream and
upstream data throughput to be unequal or asymmetrical.
, NCTI-FTTX BASICS EXAM QUESTIONS
AND ANSWERS
What would be the downstream throughput if two quadrature
amplitude modulation (QAM) channels with a throughput of 38
megabits per second (Mbps) were bonded? -
correct answer ✅76 Mbps
What are two features that were added in Data Over Cable Service
Interface Specification (DOCSIS) 3.1 to extend the viability of hybrid
fiber/coax (HFC) networks into the next decade? -
correct answer ✅Orthogonal frequency division multiplexing
(OFDM) and low-density parity-check (LDPC)
How does Internet protocol (IP) multicast differ from IP broadcast? -
correct answer ✅IP multicast traffic is only sent to specific modem
addresses on the network; IP broadcast traffic is sent to all modems
on the network
Which step in the troubleshooting process requires a discussion
with the customer to gather more detail about the problem? -
correct answer ✅Step 1: Identify the problem.
When analyzing a problem, what can the technician learn by asking
the customer to show or demonstrate the problem? -
