SONET / SDH and Ethernet serve different purposes in the realm of telecommunications, and each has its own advantages and disadvantages. While Ethernet has become the dominant technology SONET / SDH continues to be utilized in certain scenarios.

The use of Ethernet, MPLS, and IEC-61850 in power grid networks enables the deployment of robust and scalable infrastructures, as well as the use of standard protocols that facilitate interoperability, control, and service efficiency.