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.
NumberGroup provides business quality VoIP services to wholesale operators and SIP Trunk customers worldwide. We have over 1,000,000 UK and Internaiton telephone numbers are are a license UK operator with direct PSTN connectivity.