Environmental Engineering (EE) - European telecommunication standard for equipment practice - Part 3: Engineering requirements for miscellaneous racks and cabinets (ETSI EN 300119-3 V2.2.2 (2010-01))
33.040.30 Switching. Including telecommunication call charging and billing aspects / Системы коммутации и сигнализации. Включая аспекты начисления платы и выписки счета за вызов по телекоммуникациям
