Transcript Slide 1
CCNA 1 v3.1 Module 4 Review What describes frequency? • number of cycles each second 2 What are 3 characteristics of sine waves? • They repeat the same pattern at regular intervals. • They occur naturally and change regularly over time. • No two adjacent points on a graph have the same value. 3 What are 2 common ways in which the capacities of communication systems are measured? • analog bandwidth • digital bandwidth 4 What are 2 reasons why fiber optic installations would be favored over copper between buildings? • attentuation properties • no electrical interference 5 What are 2 ways binary ones and zeros are represented in fiber optic installations? • light/no light • increasing/decreasing light intensity 6 What are 3 factors that contribute to attenuation in a copper media? • long cable lengths • defective connectors • energy leaks through the insulation of the cable 7 What are 2 problems associated with impedance mismatches in copper cabling? • jitter • reflection 8 What are 2 conditions describing the transmission of signals from one wire pair which affects another wire pair? • noise • crosstalk 9 What type of wiring problem is depicted in this sample of a cable tester? • an open 10 What 2 factors need to be considered to limit the amount of signal attenuation in long Ethernet cable runs? • Type of media • Length of cable 11 What are 3 tests specified by the TIA/EIA-568-B standard for copper cable? • wire map • insertion loss • propagation delay 12 What best describes amplitude? • The height of each wave 13 In a new network installation, the network administrator has decided to use a medium that is not affected by electrical noise. Which cable type will best meet this standard? • fiber optic 14 Which of the following are true concerning crosstalk? (Choose three.) • FEXT is less of a problem than is NEXT. • Using frequency step sizes that are larger than those specified by the TIA/EIA standard has no effect on link fault detection. • A cable with a NEXT measurement of 30 dB would be considered a better cable than one which has a NEXT measurement of 10 dB. • NEXT needs to be measured from each pair to each other pair in a UTP link, and from both ends of the link. • FEXT is determined by injecting a signal into a pair of wires and measuring the signal strength on the other end of the same pair of wire. 15 Which frequencies are used by a cable tester to measure attenuation? • the highest frequencies that the cable is rated to support 16 What are 3 characteristics about square waves? • They repeat the same pattern at regular intervals. • They repeat the flat pattern on both the top and bottom of the wave. • They do not continuously vary with time. 17 What are 2 purposes of shielding in copper based media? • protect one pair of wires within the cable from noise generated by electrical signals on another pair of wires • protect the data signal from external sources of noise 18 What are pulses and why are they important in digital communication? (Choose two.) • irregular accidental spikes in energy levels • determine the value of the data being transmitted • create the timing mechanism for data transmission • increases in energy which damage data transmissions • deliberate, fixed disturbances of predictable duration 19 Two wires from different wire pairs are connected to the wrong pins on both ends of a cable. What is the wire fault name for this connection? • Split-pair 20 What 3 issues are detected by the wire map test? • Opens • Reversed-pair faults • Short circuits 21 What cable test verifies that all eight wires are connected to the correct pins on both ends of the cable? • Wire map test 22 To ensure reliable LAN communications, what should a technician be looking for when attaching connectors to the ends of UTP cable? • The wire pairs remain twisted as much as possible 23 What type of shielding does data coaxial cable use? • braided conductive • foil-screened 24