Corporate Telephony Market Size and Forecasts (2020 - 2030), Global and Regional Share, Trends, and Growth Opportunity Analysis Report Coverage:by Type (Private Branch Exchange system (PBX), Key System Unit (KSU), Voice Over Internet Protocol (VoIP)); End-User (BFSI, Government, Retail, Healthcare, Manufacturing, IT and Telecom, Hospitality, Others) , and Geography (North America, Europe, Asia Pacific, and South and Central America)