ITU-T E.412.1

ITU-T Recommendation E.412.1 provides two indexes for assessing the impact of resource discontinuities in transport networks. These two indexes are called the service outage index (SOI) and the service affected index (SAI) on the availability of services for users. They can be used to guide a network operator to arrange the OAM resources so that better services can be provided. (The word service is used in its normal sense and not as a defined term or defined ITU service).