I am able to resolve this issue by adding public IP address to loop-back interface.
Issue resolved : "Invalid Host"
May be this help in your case as well.
Thanks
Chanpreet
Hello, Are you able to resolve this issue. I have the same issue. Can you help me please.Error: Invalid host 400 Twilio Trunk —- Firewall(Doing fortwarding here to CME External Interface)—— (again double NaT to cme internal voice IP)Cisco CME Regard...