Re: PORT 7450 and 20080 is closed
Then, as long as the policy that has this vip applied is allowing TCP 7450 and 20080 toward the interface the phone system is connected, and as long as the system is listening to the ports, those ports should show up as open when you scan the wan2's IP.
I would look at the phone system side. But to prove the FGT is passing the scan packets for those ports, you can sniff the inside port with 'host 192.168.0.178' while scan is happening. You should see them passing through.
If you can't see them, now you have to run "flow debug" to see why the FGT is dropping. You can find "how to" by simply putting "fortigate flow debug" in an internet search. You need to set filter with those ports.
If you're not comfortable doing it or don't have time, just open a ticket and get help from TAC.