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 basically a set of protocol for making and breaking circuit switched connections as well as for advanced call features for the customers. ISDN is the international communication standard for data transmission along telephone lines and has transmission speeds up to 64 Kbps per channel. The emergence of ISDN represents an effort to standardize subscriber services, user/network interfaces, and network and internetwork capabilities.