not to be dense, but that was fairly greek to me. I know what all of those words mean on their own, but in sequence I get a bit lost hehe
I've got an IAX trunk set up to connect to their server (and they've got one to mine as previously stated), I've then got an outbound route that says anything with their extension pattern goes to that trunk. that stuff all makes sense to me, done it a million times. we can dial their extensions just fine.
what I don't get is where you're saying "towards their trunk".
do you mean, setting up an outbound route similar to our current one for our default where we dial 8 for an outside line. so we dial 8+ nnn-nnn-nnnn. I should create another outbound route that would be, say, 7+ nnn-nnn-nnnn and have it hit the same route as we have for their current inside extensions. then just make sure they have their default trunk set to strip the 7