Telephony topic

In telecommunication, telephony (pronounced /təˈlɛfəni/ or teh-LEH-fuh-nee) encompasses the general use of equipment to provide voice communication over distances, specifically by connecting telephones to each other. Telephones originally were connected directly together in pairs. Each user had separate telephones wired to the various places he might wish to reach. This became inconvenient when people wanted to talk to many other telephones, so the telephone exchange was invented. Each... full article at wikipedia