Synchronous Optical Network

Synchronous Optical Network (SONET).

SONET is a physical layer network technology designed to carry large volumes of traffic over relatively long distances on fiber optic cabling.

SONET was originally designed by the American National Standards Institute (ANSI) for the USA public telephone network in the mid-1980s.

SONET memo
SONET is the American National Standards Institute standard for synchronous data transmission on optical media.

The international equivalent of SONET is synchronous digital hierarchy (SDH).