пятница, 11 ноября 2011 г.

CCNA Exploration: Network Fundamentals (Version 4.0) - ENetwork Chapter 8 Answers

An installed fiber run can be checked for faults, integrity, and the performance of the media by using what device?
light injector
OTDR
TDR
multimeter

Which characteristics describe fiber optic cable? (Choose two.)
It is not affected by EMI or RFI.
 Each pair of cables is wrapped in metallic foil.
It combines the technique of cancellation, shielding and twisting to protect data.
It has a maximum speed of 100 Mbps.
It is the most expensive type of LAN cabling.

When is a rollover cable used in a network?
for connecting a host to a Fast Ethernet port on a switch
for connecting a router to another router
for connecting two routers through their AUX ports
for connecting to a switch through its console port



coax cable
rollover cable
crossover cable
straight-through cable

Which data communications standard provides broadband access in a wireless network?
GSM
Wi-Fi
WiMAX
Bluetooth
  

Which connector is used with twisted-pair cabling in an Ethernet LAN?




Which of the following is a characteristic of single-mode fiber-optic cable?
generally uses LEDs as the light source
relatively larger core with multiple light paths
less expensive than multimode
generally uses lasers as the light source


Which type of cable run is most often associated with fiber-optic cable?
backbone cable
horizontal cable
patch cable
work area cable

What are three measures of data transfer? (Choose three.)
goodput
frequency
amplitude
throughput
crosstalk
bandwidth


With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?
the magnetic field around the adjacent pairs of wire
the use of braided wire to shield the adjacent wire pairs
the reflection of the electrical wave back from the far end of the cable
the collision caused by two nodes trying to use the media simultaneously

What is a purpose of the physical layer in data communication?
to wrap data packets into frames
to make sure that MAC addresses are unique in each frame
to control the access sequence of frames to the transmission media
to convert a frame into a series of signals to be transmitted on the local media 

In LAN installations where potential electrical hazards or electromagnetic interference may be present, what type of media is recommended for backbone cabling?
coax
fiber
Cat5e UTP
Cat6 UTP
STP 

What is a possible effect of improperly applying a connector to a network cable?
Data will be forwarded to the wrong node.
Data transmitted through that cable may experience signal loss.
An improper signaling method will be implemented for data transmitted on that cable.
The encoding method for data sent on that cable will change to compensate for the improper connection

Which fiber connector supports full duplex Ethernet?


A customer installs a wireless access point at home in the closet next to the kitchen.  The customer mentions that the wireless communication performance seems degraded when the cordless phone or the microwave oven is in use.  What is the possible reason for this degradation?
The access point is close to walls.
The cordless phone joins the WLAN and shares the available bandwidth.
The wireless signal is in the same radio frequency range as the household devices are in.
The access point is on the same electrical circuit as the phone base unit and microwave oven are.
The surge of electricity when a microwave oven is in use disrupts the operation of the access point. 

Compared with UTP cable, what extra characteristic of STP cable helps reduce the effects of interference?
the metal braiding in the shielding
the reflective cladding around the core
the twisting of the wires in the cable
the insulating material in the outer jacket

Which OSI layer is responsible for managing optical signals used for data communication?
presentation
data link
transport
physical

3 комментария:

  1. Спасибо! Новые вопросы, которые не встречаются в других местах.
    Thank you! New questions that are not found elsewhere.

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  2. Thanx a lot to you, buddy... really is very useful your blogpage.

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