ITU-T Q.45-1989 Transmission Characteristics of an Analogue International Exchange - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN - Supplements (Study Group XI) 1 pp
Transmission Characteristics of an Analogue International Exchange - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN - Supplements (Study Group XI) 1 pp
ITU-T Q.45-1989 history
1989ITU-T Q.45-1989 Transmission Characteristics of an Analogue International Exchange - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN - Supplements (Study Group XI) 1 pp