I believe that the ability to use the Oleg method may depend on which ITSP service provider you are using. Simply change X_InboundCallRoute from ph (its default) to {>YourUserID:ph},{@|?:}. This will only work if your ITSP sends all calls to your user ID but it doesn't hurt anything to try it. If you get zero calls after you change it, either they aren't sending your user ID or you entered it incorrectly. Replace YourUserID with your SIP user ID.