A leased line is a private high-performance circuit leased by a common carrier between a customer and a service provider’s network. It is rented on an annual basis and usually carries voice and data or both. Leased lines are mostly used for either internet access (Internet Leased Line) or used privately between two customer sites (Point to Point Leased Line). Unlike a dial-up connection, a leased line is always active. Similarly unlike broadband, a leased line is not contended or shared and delivers dedicated guaranteed bandwidth straight to the internet backbone. Customers pay a premium for a leased line and it is supported by a comprehensive Service-Level Agreement (SLA) with a guaranteed fix time and a compensation clause. Otherwise referred to as a point to point, private circuit, private line or dedicated access. Leased Line History:
Leased lines services (or private line services) became digital in the 1970s with the conversion of the Bell backbone network from analog to digital circuits. This conversion allowed AT&T to offer Dataphone Digital Services (later re-branded digital data services) that started the deployment of ISDN and T1 lines to customer premises to connect. With the extension of digital services in the 1980s leased lines were used to connect customer premises to Frame Relay or ATM networks. Access data rates increased from the original T1 option up to T3 circuits. Access data rates also evolved dramatically to speeds of up to 10Gbit/s in the early 21st century with the Internet boom and increased offering in long-haul optical networks or Metropolitan Area Networks.