【正文】 ? This is worth 20 points A+ Guide to Managing and Maintaining Your PC, 7e 19 Networking Technologies ? Bandwidth: data transmission rate or the number of bits that can be transmitted over a work at one time (. 56Kbps, 10Mbps, 1Gbps). It is a theoritical or potential speed of a work. ? Data throughput: actual work transmission speed ? Latency: delays in work transmissions A+ Guide to Managing and Maintaining Your PC, 7e 20 Networking Technologies (cont’d.) ? Inter Service Provider (ISP) – Required for Inter connection – Upload speed is slower than download speed ? Communicating devices require same protocol – Protocol is a set of rules that governs interaction and in a work environment it means the rule that governs the munication between puters. – Inter protocol: TCP/IP (group of protocols) – Data is broken into segments, segment are put into packets A+ Guide to Managing and Maintaining Your PC, 7e 21 Figure 171 Use an ISP to connect to the Inter Courtesy: Course Technology/Cengage Learning A+ Guide to Managing and Maintaining Your PC, 7e 22 Table 171 Networking technologies Technology Speed or Speed Range Common Uses Dialup or regular telephone Up to 56 Kbps Slow access to ISP using modem and a telephone line ADSL (Assymetric DSL) Up to 640Kbps upstream and up to 8 Mbps downstream Commonly used by ISP today that are more affordable for their customers SDSL (Symmetric DSL) Up to Mbps Still used by today’s ISP but more suited for business. Both upstream and downstream are of the same speed. Fiber Optic, Optical Carrier Level Up to 50Mbps and Up to 160Gbps respectively Used as dedicated line for ISP to business and as an Inter backbone respectively. T1, T2 amp。 T3 , 6Mpbs and 45Mbps respectively Used for dedicated line for businesses like banks to ISP , , Up to 54Mbps, 54Mpbs and 160Mbps respectively Used for wireless working Ether, Fast Ether, Gigabit Ether 10Mpbs, 100Mbps and 1Gbps respectively Used in Local Area Network ? Networking Technologies – Speed and Common Uses Broadband Technologies ? Connect to the Inter – Cable modem, DSL, fiberoptic, satellite, ISDN (Integrated Services Digital Network) ? Cable modem munication – Uses existing cable lines – Always connected (always up) – TV signals and PC data signals share same coax cable – Cable modem converts PC’s digital signals to analog A+ Guide to Managing and Maintaining Your PC, 7e 23 Broadband Technologies (cont’d.) ? DSL (Digital Subscriber Line) – Group of broadband technologies ? Wide range of speeds – Uses ordinary copper phone lines and unused voice frequencies – Always connected ? Some DSL services offer connect on demand – Asymmetric DSL (ADSL): one upload speed, faster download speed – Symmetric DSL (SDSL): equal bandwidths in both directions A+ Guide to Managing and Maintaining Your PC, 7e 24 Broadband Technologies (cont’d.) ? Cable modem and DSL – Sometimes purchased on a sliding scale – Cable modem shares TV cable infrastructure with neighbors ? Service may bee degraded – DSL uses dedicated phone line ? Must filter phone line static – Similar setup for both – Installation pleted by provider or user – Both use PC work port or USB port to connect cable modem or DSL box A+ Guide to Managing and Maintaining Your PC, 7e 25 Broadband Technologies (cont’d.) ? Satellite provides highspeed Inter connections in remote areas – Available everywhere (airplanes) – Disadvantage: latency when uploading A+ Guide to Managing and Maintaining Your PC, 7e 26 Figure 175 Communication by satellite can include television and Inter access Courtesy: Course Technology/Cengage Learning Broadband Technologies (cont’d.) ? Fiber optic dedicated pointtopoint (PTP) – No line sharing – Broadband fiberoptic cable ? Television, Inter data, voice munication – Verizon technology: Fiber Optic Service (FiOS) – Cabling endpoints: carrier dependent – Upstream and downstream speeds and prices vary A+ Guide to Managing and Maintaining Your PC, 7e 27 Wireless Technologies ? Use radio waves or infrared light – Useful in places where cables difficult to install ? wireless (WiFi or Wireless Fidelity) – and ? GHz frequency Range, 100m distance – : Multiple input/multiple output (MIMO) ? GHz and 5 GHz range, 600 Mbps speed possible – : no longer widely used – and ? Manage connections between wireless devices and access points A+ Guide to Managing and Maintaining Your PC, 7e 28 Wireless Technologies (cont’d.) ? Security methods required – Encrypt data ? WEP (Wired Equivalent Privacy), WPA (WiFi Protected Access), WPA2 (WiFi Protected Access 2) – Disable SSID broadcasting ? SSID: name of the wireless access point – Filter MAC addresses ? MAC (Media Access Control) address: 6byte number uniquely identifying work adapter ? Prevents uninvited guests from using wireless LAN ? Does not prevent others from receiving data in the air A+ Guide to Managing and Maintaining Your PC, 7e 29 Activity – Checking ISP Broadband prices and speed ? Using the blank sheet of paper that will be provided make a table for the speed and prices from FSM tele for the technologies listed below – ADSL – SDSL – T1,T2,T3 (if any) ? Check out from FSM Tele website ? This is worth 20 points A+ Guide to Managing and Maintaining Your PC, 7e 30 Media used in Networking ? Two types of Medium – Wireless or Unguided – Wired or Guided Media A+ Guide to Managing and Maintaining Your PC, 7e 31 Different types of Guided Media or Cable A+ Guide to Managing and Maintaining Your PC, 7e 32 Table 172 Variations of Ether and Ether cabling A+ Guide to Managing and Maintaining Your PC, 7e 33 Figure 1718 Coaxial cable and a BNC connector are used with Th