| SDSL Broadband or Symmetric Digital Subscriber | | | | vary depending upon physical distance from the |
| Line is a high-speed Internet access service with | | | | local hubs. The fastest speed obtainable depends |
| matching upstream and downstream data | | | | on the distance between the providers building, |
| transfer rates. SDSL Broadband is the ideal choice | | | | usually the phone company, called the Central |
| for very heavy bandwidth use. For example, as a | | | | Office or C/O, and the installed modem. The |
| medium for streaming technology, Voice Over IP, | | | | distance is the length of the copper pair, which is |
| or server hosting, SDSL Broadband is the | | | | probably more than the direct "in a straight line" |
| appropriate service. Also with contention not being | | | | distance. The phone company's central office is |
| a problem, even at the worst of times, the | | | | usually located in highly populated areas or in the |
| connection will still be better than other DSL | | | | business district of a community. If the circuit is |
| connections. | | | | too long, the phone company may consider |
| This broadband will utilise a digital frequency | | | | putting in a remote central office also called a |
| travelling across existing copper telephones lines | | | | Remote DSLAM. An SDSL Broadband is generally |
| to send and receive data. When using the | | | | available in speeds from 512kb to 2Mb per second |
| telephone line for this service, phone and fax | | | | - roughly 10 to 100 times the speed of a dialup |
| services on that line must be suspended. | | | | phone line. |
| Therefore a dedicated second, or additional, line is | | | | Since this type of broadband operates on its own |
| then needed for an SDSL service. This differs | | | | dedicated line, no Microfilter (A small device that |
| from ADSL, which leaves room for both standard | | | | plugs into a normal telephone socket and splits the |
| analogue telephone equipment and the digital signal, | | | | line into both a standard telephone socket and a |
| so that one can talk on the phone or use a fax | | | | DSL broadband socket) is needed because SDSL |
| machine while online. | | | | Broadband operates on a dedicated line; there is |
| Using a copper pair running from the local phone | | | | no need to provide a filter that is designed to |
| company to the dedicated modem will provide | | | | facilitate other services. As such SDSL completely |
| internet bandwidth at a lower cost than T1 | | | | takes over while running and no other service can |
| service. SDSL Broadband is used to provide | | | | concurrently run. |
| internet access, but it is not a replacement for | | | | It will utilise the full availability of the phone line |
| communications based on protocols other than | | | | bandwidth and thus allows for the maximum |
| TCP/IP. It allows the same data transfer speed in | | | | connection available. Although some draw backs |
| both directions, it is "Symmetrical". Sometimes a | | | | exist to this equipment, the benefits surpass any |
| few lines have impairments that prevent having a | | | | such drawbacks and allow SDSL Broadband users |
| suitable all copper connection and prevent some | | | | the best DSL connection depending on their |
| from benefiting from an SDSL connection. | | | | needs. |
| It is not available in all areas and speeds might | | | | |