IRLP
The Internet Radio Linking Project, also called IRLP, is a project that links amateur radio stations around the world by using Voice over IP (VoIP). IRLP operates a worldwide network of dedicated servers and nodes offering very stable worldwide voice communications between hundreds of towns and cities. Each gateway consists of a dedicated computer running custom software that is connected to both a radio and the Internet.
Follow this link to the IRLP website, where you can get additional information and codes to link to the different repeaters that are part of the project.