SONET
synchronous optical network
SONET is an ANSI standard for fiber optic transmission of high-speed digital traffic. SONET allows internetworking of transmission products from multiple vendors and defines a physical interface, optical line rates known as OC signals, frame format, and an OAM protocol. The base rate is 51.84 Mb/s (OC-1), and higher rates are multiples of the base rate.
SONET uses synchronous high-speed signals and provides easy access to low-speed signals by mapping them into VTs.
SONET is a North American standard that is technically consistent with SDH, which is an international standard.