Determination of the Moment of the Called Subscriber's Answer in the Automatic Service - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN - Supplements (Study Group XI) 1 pp
Determination of the Moment of the Called Subscriber's Answer in the Automatic Service - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN - Supplements (Study Group XI) 1 pp