maybe the IP Can help
try this line
((RemoteEndpointMessageProperty)OperationContext.Current.IncomingMessageProperties[RemoteEndpointMessageProperty.Name]).Address;
this article can help on the long way http://keyvan.io/detect-client-ip-in-wcf-3-5
EDIT
getting the URL is not possible,
Similar question here Can I get the WCF Caller Url...?