Ok so I have a elastix with two network cards. One of the nic cards is plugged into a sip provider with a public IP. The other is plugged into the local network with a private IP address. In elastix I have two sip trunks one coming from the sip provider over nic1 and the other coming over the internet over nic2. Since nic2 is a private IP I went into sip_nat.conf and configured the external IP and everything works fine. A few days later the internet has a hiccup and goes down temporarily but now the incoming audio for the dedicated sip trunk also stops. So this makes me think that the audio to the dedicated sip trunk goes over nic1 with the public IP but sip_nat.conf tags the audio with the external data ip which makes the audio come back over nic2. So my question is if sip_nat.conf can be configured per sip trunk and not as a global setting?