SONET/SDH Alliance

The SONET/SDH Alliance was a group formed in the late 1990s to promote and develop standards for high-speed optical fiber communication networks called SONET (in North America) and SDH (globally). These standards enable different telecom companies and equipment manufacturers to create interoperable systems for reliable, efficient transmission of large amounts of data over long distances—such as internet, phone calls, and video streams. By establishing common protocols, the alliance helped ensure compatibility, fostered innovation, and supported the global growth of high-capacity fiber optic networks.