Getting Free Long Distance, Part 2
Last week we learned how to use FreeWorldDialup to connect to other VoIP users. Today we'll set up distributed Asterisk peering with the DUNDi (Distributed Universal Number Discovery) protocol. DUNDi is a peer-to-peer system for finding Internet gateways to telephony services. It operates like a blend of DNS and routing, only there is no central authority analogous to the root DNS servers. All participants publish their own authoritative routing information and share it with authorized peers. When Server A wants to know how to connect to Server B, it asks around until it receives an answer. Then it stores the information so that it can also respond to requests. You have complete control over what information and resources you choose to share--it's not a wide-open free-for-all.
This gives you a number of great options, like getting PSTN access through another server, and making long-distance calls appear as local extensions. Nearly any services that an Asterisk server provides can be made available to other peers. One way to test this and be part of an existing peer network is to join the DUNDi-test network, a free, open test network that includes PSTN termination. To prevent abuse, everyone who joins this network is required to sign and agree to abide by the General Peering Agreement, which you will find on Dundi.com. It contains instructions on how to execute it.