Inter-Asterisk eXchange (IAX) is a communication protocol used to initiate user sessions, similar to an SIP, in order to transmit and control streaming media, especially in Voice over Internet Protocol calls. IAX2 (the newest version) is a preferred method because of its flexibility, as it is compatible with a variety of codecs, and jitters and lag are minimal due to trunking and multiplexing, which means the amount of bandwidth and latency are also kept at minimal levels.
Lingo is one of the most affordable U.S. Internet phone services. Lingo offers unlimited local and long distance calls anywhere in the U.S., to Canada, and to Western Europe, plus over 25 calling features