Gesprächsgebühren; Telefongebühren (pro Anruf)
no-charge call (e.g. via Skype, etc.); toll-free call
Auslandsgespräch; Auslandstelefonat
(telephone) speech quality; sound quality; call quality
call-waiting (phone option)
intercom; intercommunication system
Buchstabiertafel; Buchstabiertabelle; Buchstabieralphabet
conference call (phone option); conference calling
station-to-station (comms)
silent time; silence period
intercom; intercommunication system