Private branch exchanges for connection to public switched telephone networks run by certain public telecommunication operators. Specification for the procedure of in-service observation for PBXs undergoing type approval.
NORM herausgegeben am 30.9.1988
Designation standards: BS 6450-7:1984
Note: UNGÜLTIG
Publication date standards: 30.9.1988
Approximate weight : 300 g (0.66 lbs)
Country: British technical standard
Kategorie: Technische Normen BS