Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!netsys!vector!telecom-gateway From: nvuxh!nao@bellcore.bellcore.com (N Ostroff) Newsgroups: comp.dcom.telecom Subject: Re: Dangerous Phone Trick Shouldn't Work Message-ID: Date: 24 Apr 89 15:10:07 GMT Sender: news@vector.Dallas.TX.US Reply-To: Neil Ostroff Organization: Bellcore (Red Bank, NJ) Lines: 26 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 145, message 6 of 7 In volume 9, issue 141, message 2, kg19+@andrew.cmu.edu (Kurt A. Geisel) describes how to make free long distance phone calls by calling collect from pay phone A to a friend waiting at pay phone B. About two years ago this scheme made headline news in New York City. It worked so well that NY Telephone disabled incoming calls to pay phones while the problem was solved. What made the fraud possible was a change in pay phone NXX codes. When fewer pay phones existed, they all shared the same NXX codes. Only pay phones were assigned these numbers. In this way, an operator could immediately tell whether a collect call or third-party billed call was being directed to a pay phone by checking the NXX code - obviously the operator would say something clever like, "I'm sorry, your call can not go through." when a caller tried this trick. However, NY Tel started numbering pay phones with arbitrary NXX codes making it impossible for an operator to differentiate between pay phones and regular phones in NYC. At least this was true until phone companies installed a database to identify all phones unwilling or unable to accept collect and third-party billed calls. I'd be surprised if your friend can still call from pay phone A to another person at pay phone B. Neil Ostroff Bell Communications Research UUCP : bcr!maestro!nao