Hi, I want to make calls using sipml5 and freeswitch. I have installed freeswitch from the git repository in an ec2 instance with elastic ip address, configured sip_profiles/internal.xml with the EIP and here the results: Using Google Chrome and the sipml5 client I register as user 1001 with password 1234 , I dial 5000 and I hear the IVR voice, also I can join to a conference I created, and hear myself in an echo test dialing 9196. No problem with that. Using Firefox 22 and the same sipml5 client I register as user 1002 and password 1234, then dial 5000, I see the audio files are played in the freeswitch cli but I can not hear anything. I guess the problem is not in my sipml5 client neither Firefox because when I use them to register to webrtc.freeswitch.org there is not any problem, I hear the voice after dialing 5000. I think I am missing some configuration in my Freeswitch server, where I also loaded the opus module and set OPUS in the file vars.xml , in the parameters global_codec_prefs and outbound_codec_prefs. I attach the console output from Freeswitch and the console output from Firefox Here the freeswitch output http://pastebin.com/S0yJxT1J Here the Firefox console output http://pastebin.com/8kBGdY3J Thanks in advance for the help -- Gustavo Salazar