Hi, I'm currently using bypass_media to make two mobile call each directly (RTP bypass FS) over the same wifi network. Once I detect that caller and callee are sharing the same WiFi network then I switch to bypass_media in dialplan (works well in big complex buildings). I would like also to use the same bypass_media mode when mobiles connect over 3g/4g data mobile network. I fully understand that both mobiles should be connected to the same mobile operator and should share a common subnet routing (without NAT) for them to 'see' each other private IP addr. Is it possible for two mobiles on the same mobile 3g/4g network to ping each other using their private IP addr? Should mobile operators allow this kind of direct peer connections (I couldn't ping internally with my Orange mobile operator)? Did anyone successfully make a direct bypass_media call between two sip mobiles over 3g/4g network? Regards assaf