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BROADBAND DIGITAL INSTALLER EXAM
QUESTIONS & SOLUTIONS 2025
What happens if a DOCSIS modem is unable to establish time-of-day (ToD)
registration? -correct-answer-If a modem is unable to establish ToD before
registration, the modem can proceed to an operational state and periodically
attempt to re-establish ToD.
What protocol is used to download a DOCSIS modem's configuration files?-
correct-answer-Configuration files are downloaded using the trivial file transfer
protocol (TFTP) that allows the modem to download software and other data
without a special password or ID.
During DOCSIS modem registration, when does the modem become sanctioned
for high-speed data (HSD) service at the authorized service levels?-correct-
answer-The modem becomes sanctioned for HSD service at authorized service
levels after a registration response message is sent to the modem and the modem
is assigned a service identifier (SID).
What security measures does DOCSIS utilize to prevent cloning of a modem's
media access control (MAC) information?-correct-answer-The baseline privacy
,2|Page
interface (BPI) was introduced in DOCSIS version 1.1 to prevent cloning of a
modem's MAC information.
What information is in a modem's configuration file?-correct-answer-The modem
configuration file contains operational parameters such as network access speeds,
quality of service (QoS), and other information detailing how the modem
functions in the network.
What message must a cable modem receive from the downstream signal in order
to begin a transmitting relationship with the cable modem-correct-answer-An
upstream channel descriptor (UCD) message, a symbol timing message (SYNC),
and a bandwidth allocation message (MAP).
What instructions might a CMTS send in a RNG-RSP message to modify the
modem's transmission parameters?-correct-answer-An adjustment to the
modem's timing interval, transmit frequency, or power level.
Why would a cable operator consider activating device class identification(DCI) as
part of a DOCSIS modem's initialization?-correct-answer-To enable the cable
operator to define special modem classes or service levels that can be prioritized
for ranging after a massive outage.
,3|Page
What does DOCSIS 3.1 seek first when synchronizing with the CMTS in order to
receive operational information?-correct-answer-An orthogonal frequency
division multiplexing (OFDM) channel that contains a set of contiguous subcarriers
called the PHY link channel (PLC)
What information does a DOCSIS 3.1 modem provide in it's Bonded Initial Ranging
Request (B-INIT-RNG-REQ)message to the CMTS?-correct-answer-The modem's
downstream service group (DS-SG) if determined.
What internet protocol (IP)connectivity modes are supported in DOCSIS 3.0 and
3.1?-correct-answer-IPV4 only, IPV6 only, alternate provisioning mode(APM) and
dual-stack provisioning mode (DPM)
what happens if a DOCSIS modem is unable to acquire the current time and date
from one or more time-of-day(TOD) servers during registration with the CMTS?-
correct-answer-The modem proceeds to an operational state and issues at least
one TOD request per 5-minute period for each server specified until local time is
established
What is the last step in a cable modem's registration?-correct-answer-When the
CMTS receives a registration acknowledge (REG-ACK) message confirming the
modem's registration
, 4|Page
How does a DOCSIS modem receive its internet protocol (IP) address?-correct-
answer-From a dynamic host configuration protocol(DHCP) server that provides
the CMTS with the modem's IP address, which is forwarded to the modem during
initialization.
When choosing the installation location for a cable modem, what should you
consider to ensure continuous and reliable operation?-correct-answer-To ensure
continuous and reliable operation, the modem should have adequate air-flow
across it and be plugged into a non-switched AC power outlet.
Why should an already installed cable service drop be inspected as part of any
installation and service call?-correct-answer-Installation standards change, so
what might have been a good installation at the time could be out of compliance
today. Therefore, the entire drop system must be checked to ensure safety,
technical, and company compliance during every installation and service call.
What is typically connected to the cable modem so that multiple computers can
connect to the Internet through a single cable modem?-correct-answer-A router
is connected to the cable modem so that multiple computers can connect to the
Internet through a single cable modem.
BROADBAND DIGITAL INSTALLER EXAM
QUESTIONS & SOLUTIONS 2025
What happens if a DOCSIS modem is unable to establish time-of-day (ToD)
registration? -correct-answer-If a modem is unable to establish ToD before
registration, the modem can proceed to an operational state and periodically
attempt to re-establish ToD.
What protocol is used to download a DOCSIS modem's configuration files?-
correct-answer-Configuration files are downloaded using the trivial file transfer
protocol (TFTP) that allows the modem to download software and other data
without a special password or ID.
During DOCSIS modem registration, when does the modem become sanctioned
for high-speed data (HSD) service at the authorized service levels?-correct-
answer-The modem becomes sanctioned for HSD service at authorized service
levels after a registration response message is sent to the modem and the modem
is assigned a service identifier (SID).
What security measures does DOCSIS utilize to prevent cloning of a modem's
media access control (MAC) information?-correct-answer-The baseline privacy
,2|Page
interface (BPI) was introduced in DOCSIS version 1.1 to prevent cloning of a
modem's MAC information.
What information is in a modem's configuration file?-correct-answer-The modem
configuration file contains operational parameters such as network access speeds,
quality of service (QoS), and other information detailing how the modem
functions in the network.
What message must a cable modem receive from the downstream signal in order
to begin a transmitting relationship with the cable modem-correct-answer-An
upstream channel descriptor (UCD) message, a symbol timing message (SYNC),
and a bandwidth allocation message (MAP).
What instructions might a CMTS send in a RNG-RSP message to modify the
modem's transmission parameters?-correct-answer-An adjustment to the
modem's timing interval, transmit frequency, or power level.
Why would a cable operator consider activating device class identification(DCI) as
part of a DOCSIS modem's initialization?-correct-answer-To enable the cable
operator to define special modem classes or service levels that can be prioritized
for ranging after a massive outage.
,3|Page
What does DOCSIS 3.1 seek first when synchronizing with the CMTS in order to
receive operational information?-correct-answer-An orthogonal frequency
division multiplexing (OFDM) channel that contains a set of contiguous subcarriers
called the PHY link channel (PLC)
What information does a DOCSIS 3.1 modem provide in it's Bonded Initial Ranging
Request (B-INIT-RNG-REQ)message to the CMTS?-correct-answer-The modem's
downstream service group (DS-SG) if determined.
What internet protocol (IP)connectivity modes are supported in DOCSIS 3.0 and
3.1?-correct-answer-IPV4 only, IPV6 only, alternate provisioning mode(APM) and
dual-stack provisioning mode (DPM)
what happens if a DOCSIS modem is unable to acquire the current time and date
from one or more time-of-day(TOD) servers during registration with the CMTS?-
correct-answer-The modem proceeds to an operational state and issues at least
one TOD request per 5-minute period for each server specified until local time is
established
What is the last step in a cable modem's registration?-correct-answer-When the
CMTS receives a registration acknowledge (REG-ACK) message confirming the
modem's registration
, 4|Page
How does a DOCSIS modem receive its internet protocol (IP) address?-correct-
answer-From a dynamic host configuration protocol(DHCP) server that provides
the CMTS with the modem's IP address, which is forwarded to the modem during
initialization.
When choosing the installation location for a cable modem, what should you
consider to ensure continuous and reliable operation?-correct-answer-To ensure
continuous and reliable operation, the modem should have adequate air-flow
across it and be plugged into a non-switched AC power outlet.
Why should an already installed cable service drop be inspected as part of any
installation and service call?-correct-answer-Installation standards change, so
what might have been a good installation at the time could be out of compliance
today. Therefore, the entire drop system must be checked to ensure safety,
technical, and company compliance during every installation and service call.
What is typically connected to the cable modem so that multiple computers can
connect to the Internet through a single cable modem?-correct-answer-A router
is connected to the cable modem so that multiple computers can connect to the
Internet through a single cable modem.
