iPhone SIP VoiP application

A VoIP application for iPhone using open source code already available online and in use by application Siphone - code available at [login to view URL] Also a desktop application (preferably mac) and server software. The difference with this application is that before placing the call, the application is to play a 15 second advertisement, streaming from an address specified on our server and set from the desktop app. Then the app is to check with the server in order to retrieve registrar details for the call. A counter will be incorporated into the server so the desktop app can log the amount of times each advertisement is made and the number of minutes used on each registrar and to what countries/lines. The server will spread the calls over different registrars to prevent overcrowding, this will be based at random but also on the amount of minutes each registrar has been used for.