At their destination, the data packets are re-grouped and converted back into the original voice signals and played through the speakers. Many of these programs even allow you to leave a voice message if the party you are calling is unavailable. Regular telephone calls require an extensive network of telephone exchanges, connected by fixed telephone lines, undersea fiber optic cables and telecommunication satellites. The high infrastructure investment by the telephone companies results in expensive long distance calls for us. A dedicated telephone exchange connection also has a lot of excess capacity or idle time during a voice call.
Internet telephony rides partially on the existing network of fixed telephone lines.
It also uses the latest technology to compress our voice signals, and to fully utilize the capacity of the telephone lines. Data packets from different calls, and even different types of data, can travel along the same line at the same time. In a nutshell, your voice goes as far as it can over the internet before it is transformed back to normal telephone systems to complete the call.