AsymmetricDigitalSubscriberLine(ADSL).docVIP

University of Guelph Humber Lab # Asymmetric Digital Subscriber Line (ADSL) Introduction:- ADSL (Asymmetric Digital Subscriber Line or DSL for short) is a high-speed Internet access service that utilizes existing copper telephones lines to send and receive data at speeds that far exceed conventional dial-up modems. The fastest dial-up modems are rated at 57 kilobits per second (Kbps), and usually operate at about 53 Kbps under good conditions. By comparison, ADSL allows data stream speeds from 1.5 to 8 megabits per second (Mbps), depending on the grade of ADSL service purchased. ADSL uses standard telephone lines to transmit upstream and downstream data on a digital frequency, which sets these data streams apart from the analog signals telephones and fax machines use. Because the ADSL signal is operating on a different frequency, the telephone can be used normally, even when surfing the Web with ADSL service. The only requirement will probably be inexpensive DSL filters on each phone or fax line, to remove any white noise on the line that might be generated from ADSL service. The asymmetric in ADSL refers to the fact that the downstream data rate, or the data coming to your computer from the Internet, is traveling faster than upstream data, or the data traveling from your computer to the Internet. Upstream data rates are slower because Web page requests are fairly miniscule data strings that do not require much bandwidth to handle efficiently. Some businesses, however, may require matching upstream rates for uploading large files. SDSL, or Symmetric Digital Subscriber Line is an option. Symmetric indicates that both data streams are operating at the same speed of 1.5 to 7 Mbps, depending on the grade purchased. SDSL service requires a dedicated telephone line because, unlike ADSL, telephone and fax services cannot share a line with SDSL service. ADSL service requires an Internet service provider (ISP), and ADSL modem. The modem is often provided free of cha