DSL

DSL (Digital Subscriber Line) technology uses common telephone lines to give broadband services. This is feasible as Dsl internet handles digital signals which are not vulnerable to noise and intrusion as analog systems.

The real meaning of the DSL system lies in continuous conversion of the existing system of carrying signals from the central office of the telephone company to the client. The telephone company fits a DSLAM to attach their lines to the ISP (Internet Service Provider), and a Dsl modem or DSL Router at the client end of their line. The system is now prepared to handle the digital signals up to the clients end. The client equipment is linked through the Dsl modem to the internet.

Normally DSL speeds range from 256 kbps (256,000 bits per second) to 24Mbps (24,000,000 bits per second) depending on the kind of technology utilized. Two normally used versions of this service are the SDSL and the ADSL. SDSL (Symmetric DSL) provides internet service able to download or upload speeds of up to 1.4 Mbps. ADSL (Asymmetric DSL) can give download speeds of up to 1.4Mpbs but upload speeds of only up to 640 kbps and also make possible simultaneous voice communication which is not offered by SDSL system.

SDSL system is designed for small businesses that have a great amount of data that needs to be uploaded whilst additional voice communication facility is not a need. ADSL conversely is designed more for home users who have more need of downloads like music, videos and much lesser requirement of uploads except e-mails.

Despite the DSL & ADSL, there are other sorts of Dsl services like VDSL &RADSL, etc. VDSL (Very high bit rate DSL) offers a quick connection but over a very small distance from the central office of the telephone company. RADSL (Rate-adaptive DSL) is a system in which the modem can regulate the speed of communication but it totally depend on the length and quality of the line. These systems, though, are not very ordinary.

One essential point to keep in mind is that the system of DSL connections is restricted to locations which are within a radius of approximately 18,000 feet (5,460 meters) from the service provider. It is clear that Dsl internet service can be offered only where telephone lines exist. There are lots of Dsl providers like Verizon dsl, AT&T DSL, Yahoo DSL, Bellsouth DSL, Sbc yahoo dsl, SBC DSL Free DSL and lots more. Their systems essentially are alike but territories served tariff structures possibly different. Since much depends upon the internet speed, one can always perform a Dsl speed test. Normally the service operators do have a provision for it; if not these facilities are accessible from organizations like C/Net.

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