Digital subscriber line Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology, for Internet access. DSL service can be delivered simultaneously with wired telephone service on the same telephone line since DSL uses higher frequency bands for data. On the customer premises, a DSL filter on each non-DSL outlet blocks any high-frequency interference to enable simultaneous use of the voice and DSL services. The bit rate of consumer DSL services typically ranges from 256 kbit/s to over 100 Mbit/s in the direction to the customer (downstream), depending on DSL technology, line conditions, and service-level implementation. Bit rates of 1 G bit/s have been reached in trials, [1] but most homes are likely to be limited to 500-800 Mbi...
Dial-up Internet access Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telephone line. The user's computer or router uses an attached modem to encode and decode information into and from audio frequency signals, respectively. In 1979, Tom Truscott and Steve Bellovin, graduate students for Duke University, created an early predecessor to dial-up Internet access called the USENET. The USENET was a UNIX based system that used a dial-up connection to transfer data through telephone modems. [1] Dial-up Internet has been around since the 1980s via public providers such as NSFNET-linked universities and was first offered commercially in July 1992 by Sprint. [2] Despite losing ground to broadband since the mid-2000s, dial-up may still be used where other forms are not available or the cost is too ...