Thank you a lot Pedro, Thank you very much Benny, @Pedro I've read yet your post, but I've hoped that for the exchange of a simple "Hello World" string, the ice_strans APIs would be sufficient :-( However, I'll try to use the functions you have indicated to me. Is it too difficult? :-/ Does this means that you also have implemented a similar application? Could you let me know the results of your experiments? ICE does what promises? Your application is able to let 2 peers speak directly, without the aid of a relay server? @Benny I appreciate your clarification :-) , you are always sound... So, I've to use the pjmedia APIs to realize the signaling part of my architecture: this is true also for the implementation of peer's registration with a RendezVous Server? In my design, the Server would be responsible for the information exchange between peers...How can, the server, adds a chance to the ICE connectivity checks? You told me that the use of a Server is the "classical STUN solution", but how 2 peers can knows each other? How can I consider the mapping and filtering policies of the NATs involved? Let me know... Bye -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20080717/dd12e98a/attachment.html