What is SDSL?

SDSL, the acronyms of  Symmetric Digital Subscriber Line  is a high-speed Internet access service used for high-loaded data transferring with matching upstream and downstream data rates, it means the data can be transferred from both direction with same bandwidth. It is primarily used for the business purpose as well as individuals where it needs to transfer the data in the bulk mass. 

SDSL  is a sort of  Digital Subscriber Line  like ADSL (Asymmetrical Digital Subscriber Line),  but it differs from it in terms of  transferring the bandwidth. ADSL is an  asymmetrical  service that  transfer data in the bulk of  bandwidth only for receiving, not for sending. SDSL uses copper telephone lines traveling across digital frequency for running high speed internet. The another difference is " SDSL is an 'always on'  service", it means whenever the user switch on the power, the connection is continuously active. So it needs  an additional or second telephone line for getting  uninterrupted internet connection because it cannot run on the engaged telephone or fax line, while ADSL leaves room for both purpose, one can talk or fax while using ADSL service, as it separates digital and analog signals. 

SDSL is faster than ADSL. The bandwidth of  SDSL can be as high as 7 mbps in both directions while ADSL can have the bandwidth of  up to 1 mbps from uploading side. SDSL modem is essential for using this service which is supplied by internet service provider and the user have to pay for it.

SDSL is a good choice for the heavy loaded high speed data transferring from both the direction but it more expensive than ADSL and it 's speed also vary according to distance. It can run over one pair of  copper wire within maximum 3 kilometer.