When a call out is done by the destination communications device (11), the calling access server (15) generates the call-out packet, which packet is then sent to the called access server (15) through the Internet (16). The called access server (15) sends a ringing signal to the destination communications...http://www.google.com.au/patents/US6801522?utm_source=gb-gplus-sharePatent US6801522 - Method of communicating with subscriber devices through a global communication network
