The waterfall has been known as the Angel Falls since the Mid-20th century; they are named after Jimmie Angel, a US aviator, who was the first person to fly over the falls. Angel's ashes were scattered over the falls on 2 July 1960. The common Spanish name Salto Ãngel derives from his surname.
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. It was first defined in 1988 in the CCITT red book.
ISDN is a circuit-switched telephone network system, which also provides access to packet switched networks, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in potentially better voice quality than an analog phone can provide.