Expanded Testing and Strategic Partnerships Simplify Interoperability Between Third-Party ONU and OLT Devices SAN JOSE, Calif., Sept. 24, 2024 /PRNewswire/ -- Harmonic (NASDAQ: HLIT) today announced expanded efforts to improve interoperability between optical network units (ONU) and optical line terminals (OLT) for fiber broadband deployment. The addition of Harmonic's new interoperability facilities for third-party ONU vendors in North America and Europe underscores the company's commitment to an Open ONU ...