If you have installed Enterprise portal and configured sharepoint services and you are able to run website on intranet but its not running on internet then you need to do one more step.
Go to sharepoint central administration site and operation menu after that you need to specify static or public ip in Alternate Ip mapping option.
If still problem not resolved then you need to check your port whether its working or not.
Go to sharepoint central administration site and operation menu after that you need to specify static or public ip in Alternate Ip mapping option.
If still problem not resolved then you need to check your port whether its working or not.