GKVoiceChatService connect iphones using internet

GKVoiceChatService connect iphones using internet i want to use this function but i want to connect people using the internet and not using bluetooth or wifi ... so how can i do this ... how can i make the iphones discover other iphones over the internet that are using the same app and connect to them ... i have a server and a very good php knowledge and very good objective c and coca knowlage ... i want to make voice chat ... so if there is better way to do it other than GKVoiceChatService please tell me