What is another word for phone system?
Pronunciation: [fˈə͡ʊn sˈɪstəm] (IPA) 
There are a variety of synonyms for the term "phone system." Depending on the intended meaning, one might refer to it as a telephone network, telecommunication system, or even a switchboard. Other synonyms could include PBX (private branch exchange), phone exchange, phone infrastructure, or communication platform. Some might also use phrases such as voice-over-IP (VoIP) or unified communications to describe a phone system with additional features beyond just voice communication. Regardless of the specific terminology used, these synonyms all refer to the infrastructure of a network or system used to facilitate communication, particularly voice calls, through various technologies and devices.
