ITU-T Recommendation E.183 Series E: Overall network operation, telephone service, service operation and human factors. Operation, numbering, routing and mobile… Tones in national signalling systems. Guiding principles for telephone announcements

ITU-T Recommendation E.182 Series E: Overall network operation, telephone service, service operation and human factors. Operation, numbering, routing… Tones in national signalling systems. Application of tones and recorded announcements in telephone ... ITU-T Recommendation E.181 Telephone network and ISDN. Operation, numbering, routing and mobile service. Customer recognition of foreign tones ITU-T Recommendation E.180/Q.35 Series E: Overall network operation, telephone service, service operation and human factors… Series Q: Switching and signalling. International automatic… Technical characteristics of tones for the telephone service ITU-T Recommendation E.184 Telephone network and ISDN. Operation, numbering, routing and mobile service. Indications to users of ISDN terminals ITU-T Recommendation E.190 Series E: Overall network operation, telephone service, service operation and human factors… Principles and responsibilities for the management, assignment and reclamation of E-Series international numbering recources ITU-T Recommendation E.191 Series E: Overall network operation, telephone service, service operation and human factors. Operation, numbering, routing and mobile services – International operation - Tones in national signalling systems. B-ISDN addressing