What Is SONET – Synchronous Optical Network?

Speed and security are two of SONET's benefits

The Network of the Office Building
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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 for the U.S. public telephone network in the mid-1980s. This standardized digital communication protocol transfers multiple data streams at the same time.

Sonet Characteristics 

SONET possesses several characteristics that make it appealing, including:

  • SONET requires less equipment than other protocols and provides increased network reliability.
  • SONET defines clear interoperability standards among different vendors' products.
  • SONET can carry nearly any high-level protocol including IP.
  • SONET includes built-in support for ease of management and maintenance.
  • SONET supports all kinds of traffic including voice, data, and video.
  • SONET offers higher security than other protocols.

The acknowledged disadvantage of SONET is its high cost.

SONET is typically used in backbone carrier networks. It is also found on campuses and in airports.

Performance

SONET performs at extremely high speeds. At the base signaling level, called STS-1, SONET supports 51.84 Mbps. The next level of SONET signaling, STS-3, supports triple the bandwidth, or 155.52 Mbps. Higher levels of SONET signaling increase the bandwidth in successive multiples of four, up to approximately 40 Gbps.

The speed of SONET made the technology competitive with alternatives such as Asynchronous Transfer Mode and Gigabit Ethernet for many years. However, as Ethernet standards have advanced over the past two decades, it has become a popular replacement for aging SONET infrastructures.