If there were any concerns that Mark Spencer was in danger of running out of good ideas, Distributed Universal Number Discovery (DUNDi) ought to lay such thoughts to rest. DUNDi is poised to be as revolutionary as Asterisk. The DUNDi web site (http://www.dundi.com) says it best: “DUNDiTM is a peer to peer system for locating Internet gateways to telephony services. Unlike traditional centralized services (such as the remarkably simple and concise ENUM  standard), DUNDi is fully distributed with no centralized authority whatsoever.”
Think of DUNDi as a large phone book that allows you to ask peers if they know of an alternative VoIP route to an extension number or PSTN telephone number.
For example, assume you are connected to the DUNDi-test network (a free and open network that terminates calls to traditional PSTN numbers). You ask your friend Bob if he knows how to reach 1-800-555-1212, a number for which you have no direct access. Bob replies, “I don’t know how to reach that number, but let me ask my peer Sally.”
Bob asks Sally if she knows how to reach the requested number, and she responds with, “You can reach that number at IAX2/dundi:very_long_password@hostname/extension.” Bob then stores the address in his database and passes on to you the information about how to reach 1-800-555-1212 via VoIP, allowing you an alternative method of reaching the same destination through a different network.
Because Bob has stored the information he found, he’ll be ...