Apparatus with one or more particular functions for connection to certain public switched telephone networks. Specification for series connected apparatus, Apparatus having less than maximum allowable impairments— 8 стр.
Apparatus with one or more particular functions for connection to public switched telephone networks run by certain public telecommunications operators, Specification for general requirements— 12 стр.
Apparatus with one or more particular functions for connection to public switched telephone networks run by certain public telecommunications operators, Specification for general requirements— 12 стр.
