The large cost savings offered are fuelling rapid growth in the global consumer market. Internet telephony providers claim that calls are transmitted almost in real time, with the PC digitising the speaker's voice and assembling the data into internet protocol packets transmitted at a rate of between 30-50 packets per second, creating sound that appears to be continuous. There is a small delay about one-tenth of a second between the time a word is spoken at one end and when that word is heard on the other end. But this is usually less than the delay involved in transmitting international telephone calls by satellite.
Calls can either be free or cut-rate.
HotTelephone, for example, offers free calls to 30 countries as distant as China and Singapore. But phoning abroad is worth while. Calls to most European countries, as well as Hong Kong, Australia, New Zealand, and Israel are charged at eight cents per minute. Go2Call offers a mixture of options. There are free calls within the UK and to Canada and the US, plus Belgium, Germany, Ireland, the Netherlands, and Sweden.