his Recoinmetidation is one of a set of closely related Recommendations comprising E.8 10, E.825, E.830, E.X45,E.850 aiid E.855,concenied with the accessibility, retainability and integrity of telephone services.
ITU-T E.830-1992 history
1992ITU-T E.830-1992 Models for the Specification Evaluation and Allocation of Serveability and Service Integrity (Study Group II) 5 pp