On August 21, 1996, as part of a continuing series
of technical seminars, SCD network engineer Chris Fair presented an
overview of SONET (Synchronous Optical Network) technology at the NCAR
Mesa Lab. He provided a brief introduction to SONET concepts, terms,
architecture, and operation. SONET is a specification for high-performance fiberoptic transmission. Proposed by Bellcore and standardized by the American National Standards Institute (ANSI), SONET is the North American counterpart of the worldwide Synchronous Digital Hierarchy (SDH), which is a multiplexing strata for OSI layer 1 services.
SONET addresses the need for compatibility and interoperability among different vendors' terminal (multiplexing) equipment. It takes advantage of the high reliability of modern fiberoptic transmission systems and facilitates increased network management capabilities for users and service providers while accommodating the existing DS-1 and DS-3 asynchronous services.
The seminar included discussion of the Optical Carrier (OC) frame format, how SONET transports existing T-carrier services, and SONET's relationship to Asynchronous Transfer Mode (ATM).