TONY@mcgill1.bitnet (Tony Harminc) (05/08/91)
>Date: Tue, 7 May 1991 11:19:53 EDT >From: KATH MULLHOLAND <K_MULLHOLAND@unhh.unh.edu> >Subject: Collect and Third-Party Screening > >We just received our April bill. We have screening on 300 phones, and >received bills for ten of them. A total of fourteen calls were >billed. Two were collect calls from "MTL PQ" billed by AT&T (No >credit will be given -- international calls aren't covered by the >screening.) .... Back in the "good old days" there was a scheme to prevent collect calls to coin phones: within each CO prefix one entire thousands block was set aside for coin phones, and operators had a list of which numbers were suspect. (For far away places they had to contact Rate & Route who had grand master lists, or even sometimes inward operators if the place was really out of the way.) So for instance in many areas all numbers of the form NNX-0XXX were at least potentialy coin phones and a collect call to such a number would not be completed without further checking. This scheme certainly worked internationally. Now I assume this information is all in a database somewhere - surely they can't still be using the "thousands digit" scheme, can they ? So if calling card numbers can be verified internationally in a second or two, why can't collect and third-party prohibition be handled similarly ? Tony Harminc