What Is DSL?
by: Toh Poh
DSL stands for Digital Subscriber Line. It is a service that makes use of existing copper telephone wires for delivering data services at high speeds. It does not hamper the existing telephone line. You can surf the Internet and talk on the phone, simultaneously.
DSL offers speeds that are around 5 to 25 times higher than a typical 56Kbps (56 kilobits per second) dial-up connection. It is an always-on type of connection. This implies that websites would load quickly, downloads would be faster, buffering of videos would be fast and smooth and the domain of online games would have no limits.
Based on the types of service, DSL can be categorized in three divisions: ADSL, IDSL, and SDSL.
ADSL stands for Asymmetric Digital Subscriber Line. It offers download speeds of 1.5 Mbps and upload speeds of 384 Kbps. In order to acquire a ADSL connection, your location has to be within 3 miles of your local telephone office. Also, a DSL router is needed for this type of connection. [note by russ: as of 2008, DSL can provide over 6 Mbps.]
IDSL is a ISDN Digital Subscriber Line service which requires an ISDN router. It provides a connection speed of 144 K. in this type of connection distance is not a component to be considered.
SDSL means Symmetric Digital Subscriber Line. The speeds available under this type of DSL connection depends on the distance between your location and your local telephone office. The speed of downloads and uploads can go up to 1.1 Mbps.
Advantages of DSL
Disadvantages of DSL
DSL vs Cable Modems
These tiny boxes filter the high frequency ADSL signal and allow telephones, fax machines, etc. to work on the same line.
screenshot: Didier Misson