CHAPTER FOUR supplementary questions answers. (Group exercise in March). 1. What the the two types of twisted pair media? Shielded twisted-pair (STP) and Unshielded twisted-pair (UTP). STP has better EMI protection. 2. What are the names of the two common types of coaxial cable? Thinnet and Thicknet. 3. What is a major benefit of fiber-optic cable? What is a major drawback? Major benefits are immunity to EMI, high bandwidth, and the long distances the cable can run. Major drawback is co$t of fiber optic. 4. What are some reasons a wireless media would be chosen over a bound media? Spaces where cabling would be impossible or terribly inconvenient. These would include open lobbies, inaccessible parts of buildings, older buildings, historical buildings where renovation would not be allowed, and outdoor installations such as at an outdoor rock concert or a construction site. People who have to move around a lot within their work environments. Nurses and doctors making rounds at a hospital. Network administrators who need to troubleshoot a large office network. People who travel outside the work environment and need instant access to network resources. Satellite offices or branches that need to be connected to a main office or location. **** Multiple choice questions 1, 2, 3, ..., 23, 24 **** 1. Which two of the following are true about coaxial Thinnet? B. It has 50-ohm impedance and requires a 50-ohm terminator. D. Thinnet includes an insulation layer. 2. Transceivers for Thicknet cables are often connected using what device? B. Vampire taps 3. Which two of the following are true about UTP? C. Telephone systems use UTP. D. UTP is more sensitive to EMI than Thinnet. 4. Which of the following is not a permissible location for coaxial PVC cabling? Note: PVC = Polyvinyl Chloride B. Above a drop ceiling PVC emits toxic fumes when it burns and is not permitted in plenum spaces. Thus the term plenum grade cabling or wiring means cable that is more expen$ive, but is permitted in the plenum area because it does not include and PVC containing materials. 5. UTP Category 3 uses how many twisted pair(s) of cables? C. 4 pairs 6. Transmission rates of what speed are typical for fiber-optic? C. 100 Mbps 7. What is a transceiver that connects a wireless node with the LAN? B. An access point 8. What type of transmissions are designed to reflect the light beam off walls, floors, and ceilings until it finally reaches the receiver? B. Scatter infrared. (It does not require line of sight). 9. Which three of the following are forms of mobile network technology? A. Cellular B. Packet-radio D. Satellite station 10. Which of the following cable types supports the greatest cable lengths? C. Thicknet 11. What are two advantages of UTP cable? A. Low cost B. Easy installation 12. What are two benefits of shielding in a cable? B. Reduction in EMI radiation. C. Reduction in sensitivity to outside interference. 13. What are two disadvantages of fiber-optic cable? B. Expensive hardare C. Expensive to install 14. What cable type is ideal for connecting between two buildings? D. Fiber-optic. 15. What do radio transmissions require more of as frequency increases? Increasingly_____________. C. Line-of-sight. 16. Which two statements are true of microwave systems? B. All microwave systems operate in the low-gigahertz range. C. Microwave signals are sensitive to EMI and electronic eavesdropping. 17. For what are DIN Connectors primarily used? B. Cabling Macintosh computer to AppleTalk networks. 18. Which two connectors are frequently used with STP cable? C. IBM unisex connectors D. AppleTalk DIN connectors 19. Which two connectors are commonly used with coaxial cable? B. T-connectors D. BNC connectors 20. Which two statements are true of Thinnet cabling? A. A T-connector must be used to connect the PC's network board to the network. D. One terminator must be grounded. 21. Which form of spread-spectrum media breaks data into chips, which are transmitted on separate frequencies? D. Direct sequence modulation. The data is spread across different frequencies when being transmitted. The spread of the data is circulated between the different frequencies being used. 22. What wireless system typically operates in the low gigahertz range? B. Terrestrial microwave. Laser, Infrared and Aubible sound all operate at a lower frequency range. 23. What is the term used to desribe the time required for a signal to arrive at its destination in a satellite microwave system? B. Propagation delay. 24. You are to choose a transmission media type for a network. The capacity for intruders to "sniff" information directly from the network is a major concern. Also, EMI is a major consideration. Primary objective: The transmission media must be capable of transferring the data over ten miles. Secondary objective: Electrical lightning storms are common in the area, so the transmission media needs to be independent of the weather. Secondary objective: The transmission media needs to be relatively inexpen$ive. Suggested solution: Implement the network using fiber-optic cabling. B. This solution meets the primary objective and only one of the secondary objectives. Fiber-optic cable can allow the network to span many miles, and also enable it to be immune to whatever the weather conditions are. However, it is among the most expensive solutions to implement, so the other secondary objective is not met.