Advice of Charge: Charging Information at Call Set-Up Time (AOC-S) - Integrated Services Digital Network (ISDN) - Service Capabilities - Supplementary Services in ISDN (Study Group I) 12 pp
The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union.The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.The World Telecommunication Standardization Conference (WTSC),which meets every four years,established the topics for study by the ITU-T Study Groups which,in their turn, produce Recommendations on these topics.