Network+ Chapter 5: Network Cabling

What kind of cable uses BNC connectors? Which connector is likely to be used by cable TV? A. Coaxial Cable, F-Connector B. Twisted-pair Cable, RJ-11 C. Copper Cable, RJ-45 D. Fiber-optic Cable, MTRJ

- A. Coaxial Cable, F-Connector - F-connectors, attach to coaxial cable so that the pin in the center of the connector is the conducting core of the cable. - BNC connector is crimped, compressed, or twisted onto a coaxial cable.

What is a twist ratio, and why is it important?

- Twist Ratio, the number of twists per meter or foot. - The more twists per foot in a pair of wires, the more resistant the pair will be to crosstalk or noise.

Which kind of multiplexing assigns slots to nodes according to priority and need? A. WDM (wavelength division multiplexing) B. STDM (statistical time division multiplexing) C. TDM (time division multiplexing) D. CWDM (coarse wavelength division multiplexing)

- B. STDM (statistical time division multiplexing) - STDM(statistical time division multiplexing), assigns time slots to nodes (similar to TDM), but then adjusts these slots according to priority and need.

Which of these categories of twisted pair cable can support Gigabit Ethernet? A. Cat 5, Cat 6, Cat 7 B. Cat 5e, Cat 6, Cat 3 C. Cat 5e, Cat 6a, Cat 7 D. Cat 6, Cat 7a, Cat 5

- C. Cat 5e, Cat 6a, Cat 7 - CAT 5e (enhanced) 1000 Mbps 350 MHz Higher-grade version of Cat5 higher twist ratio - CAT 6a (augmented) 10 Gbps 500 MHz Reduced attenuation and crosstalk. Reliable Gb - CAT 7 (Category 7) 10 Gbps 600 MHz Higher frequency, wire pair has shielding

Suppose you're assisting with a cable installation using fiber-optic cabling that will support Gigabit Ethernet. You're approved to install segments up to 4000m in length. What kind of cable are you using?

- SMF, allows to accommodate the highest bandwidths and longest distances (without requiring repeaters). - MMF, is not suited to distances longer than a few kilometers.

What is the difference between short circuits and open circuits?

- Short Circuit, is an unwanted connection, such as when exposed wires touch each other. - Open Circuit, is one where needed connections are missing, such as when a wire breaks.

Why is SMF more efficient over long distances than MMF?

- Signals traveling over multimode fiber experience greater attenuation than those traversing single mode fiber, therefore, is not suited to long distances longer than a few Km

What fiber is used in fiber-optic cabling to protect the inner core and prevent the cable from stretching?

- Kevlar (a polymeric fiber) surrounds the plastic buffer to prevent the cable from stretching, and to protect the inner core further.

How is latency measured, and in what unit?

- RTT (round trip time), the most common way to measure latency or the length of time it takes for a packet to go from sender to receiver, then back from the receiver to sender. RTT is usually measured in milliseconds.

Which fiber transceiver is the same as SFP transceivers, but can support network speeds over 10 Gbps?

- SFP+, developed later than XFP and is the same module size as SFP, theoretical maximum transmission speed is 16 Gbps

What characteristic of optical transmissions is primarily responsible for the distance limitations of fiber-optic cabling?

- SIZE AND SCALABILITY, depending on the type of fiber-optic cable used, segments lengths vary from 2 to 40,000 meters. Optical Loss, or the degradation of the light signal after it travels a certain distance away from its source will hit the maximum limit.

Why do APC ferrules create less back reflection than UPC ferrules?

- APC connection reflects any signal loss in a different direction than the source of the signal. Back reflection worsens in UPC connections over time, but APC connections are not as sensitive to degradation from repeatedly disconnecting and reconnecting cables.

Which fiber connector contains two strands of fiber in each ferrule? A. MTRJ B. SC C. ST D. LC

- A. MTRJ - MTRJ N/A Polish 2 Fibers Full Duplex

Suppose you're creating patch cables to be used in a government office. What color wire goes in the first pin? A. White/Orange B. White/Green C. Brown D. Blue

- B. White/Green - T568A Wiring Pin #1 White/Green, The Federal Government requires T568A on all federal contracts.

What is the earliest twisted-pair cabling standard that meets the minimum requirements for 10GBase-T transmissions? A. Cat 5e B. Cat 5 C. Cat 6a D. Cat 7

- C. Cat 6a - CAT 6a (augmented) 10 Gbps 500 MHz Reduced attenuation and crosstalk. Reliable 10Gb

What type of fiber cable problem is caused when pairing a 50-mircon core cable with a 62.5-mircon core cable? A. Dirty Connectors B. Wavelength Mismatch C. Fiber Type mismatch D. TX/RX Reverse

- C. Fiber Type Mismatch - Fiber Type Mismatch- this term is misleading because a fiber type mismatch is actually more of a fiber core mismatch.

Which part of a toner and probe kit emits an audible tone when it detects electrical activity on a wire pair? A. TDR B. Tone Generator C. Tone Locator D. Toner

- C. Tone Locator - Tone locator (or probe), a device that emits a tone when it detects electrical activity on a wire. They are often sold together as a kit.

What kind of tool can measure the distance to the location of damage in a cable?

- Cable performance tester, measures the overall performance of a cabling structure, line tester, certifier, network tester. Allows you to perform the same continuity and fault tests as a continuity tester, but can also be used to: o Measure the distance to a connectivity device, termination point, or damage in a cable

Which transmission characteristic is never fully achieved? A. Latency B. Throughput C. Bit Rate D. Bandwidth

- D. Bandwidth - Bandwidth, the amount of data that could theoretically be transmitted during a given period of time.

Which kind of crosstalk occurs between wire pairs near the source of the signal? A. Alien B. TX/RX reverse C. FEXT D. NEXT

- D. Next - NEXT(near end crosstalk), crosstalk that occurs between wire pairs near the source of the signal