Dear Morpheus
thanks for your answer.
I had disable the firewall so the traffic pass in any direction.
So you mean that I will create TWO SNAT rules one in the vcd network and one in the EXTERNAL newtork?
The first rule I had create translate 172.16.1.0 to 192.168.0.0 class and I put in the VCD network connected to the edge
but the second that you say which configuration must have?
thanks
Giovanni