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The Need For Speed Terry Foley Rhonda Hoskins Jerry Gilroy Jill Morgan. High Speed Internet Technology. Outline. What is DSL? Where did DSL originate? How does DSL work? What types of DSL are available? Myths and Truths about DSL Its closest competitor
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The Need For SpeedTerry FoleyRhonda HoskinsJerry GilroyJill Morgan High Speed Internet Technology High Speed Internet Technologies
Outline • What is DSL? • Where did DSL originate? • How does DSL work? • What types of DSL are available? • Myths and Truths about DSL • Its closest competitor • http://computingcentral.msn.com/topics/bandwidth/howfast.asp
What is DSL? • DSL – Digital Subscriber Line • Uses ordinary telephone wire • Speed varies depending on type • An “always on” service – No dial-up • One line carries both data and voice
Where Did DSL Originate • Created by Bellcore in 1989 • To deliver video on-demand to compete with cable TV • Never really used for this • People noticed the potential for internet applications
How Does DSL Work • Implemented over the “last mile” • Uses digital technology • Utilizes line-coding scheme • Divides line into 3 bands • Lower for voice, Higher 2 for data
How Does DSL Work cont’d • Phone company must install special router – DSL access multiplexer • This transfers data from copper line to larger backbone • CO must be approx. 18000 ft from the end user for top performance • End user must have special router or modem
Types Of DSL • HDSL – High-Data-Rate DSL • ADSL – Asymmetric DSL • RADSL – Rate Adaptive DSL • SDSL – Symmetric DSL • VDSL – Very-High-Rate DSL
Myths And Truths • Myth – DSL is easy to install • Truth – Technician needed to install modem and wiring • Myth – Speed of DSL • Truth – Performance is effected by electromagnetic noise and distance
Its Closest Competitor • Cable – It provides similar speeds, service and technology • Uses local TV line to give continuous connection