I have been investigating the various VoIP technologies used for linking repeaters together. And I understand that each system is a different way to accomplish the same thing. Echolink, D-Star, Wires, IRLP, etc..... But I am a bit confused. What I don't find is specific information about the strengths and weaknessess of each system. In other words is one sytem better suited for say setting up a series of linked repeaters for wide area coverage or does another system offer better functionality for setup up a temporary patch between two nodes in different states? I know this seems random, but at present I don't have any specific goals in mind. I am just looking for general knowledge on the subject for future experimentation. As such what are some good online/printed resources covering this subject. Thanks for the help.