History

• The first widely used version of digital subscriber lines (DSL) was HDSL (high bit-rate digital subscriber line) in the 1990s, according to writer Gareth Marples. Phone companies could provide HDSL to corporate customers using phone line technology that already existed to send digital signals; however, this technology required separate phone lines. In the mid-1990s, DSL became the answer to the individual consumer's call for high-speed Internet access. The introduction of the Telecommunications Reform Act of 1996 allowed telephone, cable and Internet service providers (ISPs) to overlap markets and compete against one another. Phone companies began providing DSL to consumers via phone lines. DSL technology has improved, and DSL service no longer requires multiple phone lines. Marples explains that DSL became a popular choice for high-speed Internet access, and by the end of 2001, the global DSL subscriber base had expanded to 18.7 million users.
  
  

Identification

• Phone companies such as AT&T and Verizon have branched out from offering only phone service and have become Internet service providers as well, providing DSL service to their customers' home or place of work via phone lines. Local phone companies may also provide DSL Internet service. Typically speaking, phone companies tend to offer DSL service because their existing services already use the phone lines. Cable companies such as Time Warner or Cox also offer Internet services to their customers, but these connections rely on the coaxial cable connections as cable television service, not phone lines.
  
  DSL providers supply customers with a DSL-compatible modem that connect to the phone jack via a telephone cord and to the customer's computer via ethernet cable. DSL does not use a computer's internal modem hardware like dial-up connections.
  
  Other Internet connections, such as T1, rely on specialized wires and hardware in order to function properly.
  
  

Availablity

• DSL Internet service is widely available through larger companies such as Verizon and AT&T or local phone companies such as TDS Metrocom out of Milwaukee, Wisconsin. Because most buildings are equipped with phone lines, DSL providers do not need to install new hardware or lines. It is common practice for companies to bundle phone, Internet and television services together to attract new customers. Consumers can sometimes save money by ordering bundled services this way.
  
  Some DSL providers may limit transfer (bandwidth) usage in their plans while other providers offer unlimited usage. Verizon also offers different DSL speed packages to its customers, at varying prices. The "Starter" plan offers download speeds of up to 1 Mbps (megabits per second) while the "Turbo" plan boasts download speeds up to 7.1 Mbps. When purchasing online, the former plan costs $49.99 per month and consumers can purchase the latter for $54.99 per month with a 2-year contract.
  
  

Benefits

• Unlike dial-up connections, DSL connections are always on. DSL service typically does not require consumers to log in with a username and password so there is no log-in delay. Speed is another benefit of DSL over other connection types. According to Summersault, DSL can provide a connection speed from 128 Kbps (kilobits per second) to 8 Mbps (megabits per second). In comparison, dial-up connections can only reach up to 56 Kbps. Even the slowest DSL connection is still more than twice as fast as the quickest dial-up connection. DSL service is comparable to T1 connections that operate at 1.544 Mbps. DSL Reports also suggests that other users generally cannot affect the DSL service a customer has because of DSL's dedicated circuits.
  
  

Considerations

• The speed of DSL overlaps with cable connections, although cable ultimately has more speed potential than DSL. The distance between a customer's home and place of work and the DSL provider's office can affect the performance of the Internet connection. According to DSL Reports, a distance less than 5,000 feet should not disturb any DSL at any speed. However, a distance of 10,600 to 15,000 feet is the "danger zone," and some DSL providers will not accept an Internet service order from a new customer within this zone. DSL Internet service may require that the consumer attach a filter between his phone jack and other systems that use the phone lines such as telephones, security systems or fax machines. Deaf phone users who have a Telecommunication Device for the Deaf (TDD) would use a splitter, instead of a filter.