Terminal and Transit Control Signalling System for Telex and Similar Services on International Circuits (Type D Signalling) - Telegraph Switching Specific Signalling Schemes and Interworking Between Signalling Systems (Study Group IX) 28 pp
The ïïü 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