fcox3rd

We have 2 new 2801 routers in two different locations. The telephone company has installed two cisco IAD's to deliver trunks and internet to each location. Thy told us they were going to bond the two IAD's together for us. What they are really going to do is just put a policy that says traffic going between these two networks will not go out to the internet. They will also provide us with QOS using DSCP. I have only done voip over point-to-point t1. I have not had to use NAT. What I am reading is that I will probably only get one way audio becouse nat does not deal with the RTP traffic. Are their any workarounds for this yet without using a VPN? Thanks for any help. By the way cisco says they support Sip through Nat starting with OS 12.2?