Editing Leased line (section)

==History==
Leased line services (or [[private line]] services) became digital in the 1970s with the conversion of the Bell [[backbone network]] from analog to digital circuits. This allowed AT&T to offer Dataphone Digital Services (later re-branded digital data services) that started the deployment of [[ISDN]] and [[Digital Signal 1|T1]] lines to customer premises to connect.<ref>Microsoft Encyclopedia of Networking, Second Edition. Microsoft Press. 2002.</ref>

Leased lines were used to connect [[mainframe computer]]s with terminals and remote sites, via [[IBM]]'s [[Systems Network Architecture]] (created in 1974) or [[Digital Equipment Corporation|DEC]]'s [[DECnet]] (created in 1975).

With the extension of digital services in the 1980s, leased lines were used to connect customer premises to [[Frame Relay]] or [[Asynchronous Transfer Mode|ATM]] networks. Access data rates increased from the original T1 option with maximum transmission speed of 1.544&nbsp;Mbit/s up to T3 circuits.

In the 1990s, with the advances of the Internet, leased lines were also used to connect customer premises to [[ISP point of presence]] whilst the following decade saw a convergence of the aforementioned services (frame relay, ATM, Internet for businesses) with the [[MPLS]] integrated offerings.

Access data rates also evolved dramatically to speeds of up to 10&nbsp;Gbit/s in the early 21st century with the [[Internet boom]] and increased offering in long-haul optical networks or [[metropolitan area network]]s.