AIF WCF service : how to make it work just through IP address

Hi All,  For our project we were deploying AIF service as WCF. Now the problem is the service does works good if we are calling it by hostname. But we are not getting able to call the service properly just by using IP address. For our perticular use case our service is suppose to be deployed in a machine with public ip address and the client devices are suppose to be doing communication with just this ip address. Can you let us know how can we enable this in AIF service? Just to let you know we are using AX 2012 R2 and at present we are integrating with windows 8 but in future we may be consuming the service in other mobiles devices like Android, iOS device etc.