Network Essentials Ch 4

Why is copper cabling susceptible to eavesdropping?

Because electrical signals traveling down a copper wire create an electromagnetic field that can be detected outside the wires, copper wire is susceptible to electronic eavesdropping.

You hand a technician a crossover cable to make a connection between devices. Which device pair are you most likely asking him to connect?

Switch-to-switch

List four of the typical components of a twisted-pair cable plant.

The sheath, the shielding, and the two twisted pairs.

In an MDI device, which two pins does the device use to transmit?

1 & 2

What is the maximum cable length for both category 5e and category 6 UTP cable?

100 meter

What is the maximum bandwidth for a network cable using category 5e UTP cable?

1000Mbps

A signal has just been received from the WAN link on your network. Using the given components, which of the following shows the path that the signal would take from the WAN to a workstation on your network? Assume all components are used at least once and that some components may be used more than once. 1-backbone cabling 2-entrance facility 3-MDF 4-horizontal wiring 5-IDF 6-work area

2, 1, 3, 1, 5, 4, 6

Differential signal

A method for transmitting data in which two wires of opposite polarity are used.

IDF (Intermediate distribution facility)

A telecommunications closet that houses the cabling and devices for work area computers.

Which of the following are components of wireless networks? (Choose all that apply.)

Access Point (AP), Router

Cable Plant

All the cables and connectors that tie a network together.

MDF (Main Distribution Facility)

An equipment and cabling room that serves as the connecting point for backbone cabling between buildings and between IDFs.

An Ethernet cable runs across a warehouse that is 120 meters in length. The bit signals are so weak that they cannot be accurately read by the receiving station. What is the term for this problem?

Attenuation

You are running a length of fiber optic cable between two wiring closets. What best describes the cable you are running?

Backbone cabling

What really determines the ________ of a cabling type is how fast a transmitting device, such as a NIC, can generate bit signals on the medium

Bandwidth

List five criteria you should consider when choosing media.

Bandwidth, budget, environmental considerations, span, and existing cable plant.

You are asked to make an inventory of all the cables and connections in your network. What are you being asked to inventory?

Cable plant

Describe twisted-pair cabling.

Comes in two types, shielded (STP) and unshielded (UTP). Consists of one or more pairs of insulated strands of copper wire twisted around one another and housed in an outer jacket or sheath

Patch Cable

Connects a patch panel to a switch or hub.

When copper wires are bundled together, they are susceptible to ____________, a form of interference where the signals leak out onto other wires.

Crosstalk

Which type of interference is caused by wires in the same cabling bundle?

Crosstalk

The entrance facility is the place where the connection to a WAN is located. It is the point where the LAN equipment ends and a third-party provider's equipment and cabling begins. What is another name for this point?

Demarcation point

Hertz

Expresses how many times per second a signal or electromagnetic wave occurs.

Although different networking standards specify different media, bandwidth, and media length, they all use the same type of encoding.

False

Compared to SMF, MMF cable costs more and generally works with laser-based emitters but spans the longest distances and is used in higher-bandwidth applications.

False

The length of cable between the wall jack and a patch panel is called vertical cabling.

False

What type of wiring should be used for a high-speed connection between two buildings?

Fiber-optic

What are the benefits of fiber-optic cabling?

Fiber-optic is capable of much higher bandwidths. Fiber-optic cabling is immune to EMI and RFI so it has no problem with interference. It also has no leakage so it is highly secure, almost impervious to eavesdropping. Because of low attenuation, fiber-optic cable can travel greater distances at a higher bandwidth.

You are instructing a cable installer where to run the UTP cable that goes from the work area on the third floor of your building to the place where it connects with a patch panel and switches. To which facility should you tell the installer to run the cable?

IDF (Intermediate distribution facility)

What is the difference between a crossover cable that can be used for 100BaseT networks versus one that is suitable for 1000BaseT networks?

In 1000BaseT, each wire pair is capable of transmitting and receiving data.

A type of wireless network that uses light beams to send signals between two devices and is prone to interference from visible light sources is called ____________.

Infrared

Backbone Cabling

Interconnects telecommunications closets and equipment rooms.

What are the benefits of installing a wireless network?

Less wires to deal with, easier installation.

Which of the following are types of infrared LANs? (Choose all that apply.)

Line-of-sight Reflective Scatter Broadband optical telepoint

What is the difference between an MDI device and an MDI-X device? How does the difference affect the cabling used?

MDI transmits on pins 1 and 2 and receives on pins 3 and 6, MDI-X is the opposite. MDI can use straight-through, MDI-X uses crossover cables.

What is a disadvantage of using fiber-optic cabling versus twisted-pair cabling?

More difficult to install, more fragile

Which type of wireless technology bounces transmissions off walls and ceilings to deliver signals from sender to receiver and is often used with TV remotes?

Scatter infrared

Which of the following is a length of cable that connects a computer to either a networking device or to an RJ-45 jack?

Patch cable

What are the three most common types of wireless communication and the frequencies they use?

Radio—10 KHz to 300 MHz Microwave—300 MHz to 300 GHz Infrared—300 GHz to 400 THz (terahertz)

Horizontal Wiring

Runs from work area's jack to telecommunications closet.

What type of wireless transmission technology is used for 802.11n networks running at 2.4 GHz?

Spread-spectrum radio

What is structured cabling and why should you use it?

Structured cabling specifies how cabling should be organized, it relies on extended start physical topology. You should use it because it keeps everything organized.

Which of the following is NOT one of the main differences between the types of network cabling?

The ability to send and receive signals

Encoding

The method used to represent bits on a medium.

Because fiber-optic cabling uses light pulses instead of electrical signals, it is immune to interference and highly resistant to eavesdropping.

True

Wireless and wired networks are both susceptible to RFI.

True

IrDA Device

Use infrared signals to communicate

An OPM measures the amount of __________ transmitted by a device and whether the amount meets the requirements for the device you're connecting.

light

If you want to run cabling in the space between a false ceiling and the true ceiling, you must use ________-rated cable.

plenum