Hi Benny, thanks for your answer. For some reason if I write --stun-srv stun.pjsip.org on the command line it says invalid input, is weirdbecause if for example I enter +a it let me add a new account but if I enter --no-vad or !a it says invalid input. (I understand command line as selecting the text field on the iPhone screen an entering a command, that where I enter the others commands like +a to add the account) Anyway I manage to set up the STUN server by adding this line of code on the XCode in the app_init method: app_config.media_cfg.no_vad = PJ_TRUE; app_config.cfg.stun_host = pj_str ("stun.pjsip.org"); Now, when I run the app it detects the STUN server and if I put 'n' in command line it says "NAT detected as Symmetric" The bad news for me are that Im still unable to hear any sound on my local iPhone speaker. I dont know if maybe I can print some other log that can help to find my problem, do you know? Thanks in advance and best regards, Pablo N. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20100930/2bac6384/attachment.html>