Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!bellcore!texbell!vector!telecom-gateway From: amb@cs.columbia.edu (Andrew Boardman) Newsgroups: comp.dcom.telecom Subject: Re: While Phone Rings, Charges May Begin Message-ID:Date: 10 Aug 89 15:05:52 GMT Sender: news@vector.Dallas.TX.US Organization: Columbia University Department of Computer Science Lines: 17 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 287, message 10 of 12 In article tanner wrote: >) ... green box ... tone to payphone >Do payphones not use out-of-band signalling? It would seem to invite >abuse if they used in-band signalling, especially if someone were >inclined to carry a recording of money being dropped into the thing. They most certainly do use in-band signalling; in fact, such a recording was floating around department where I used to work. (For those that keep track of such things, a circuit hardwired to produce the tones necessary (coin deposit, not coin return) is referred to as a "red box". (Construction is trivial, but generally I prefer to pay for the service I get from AT&T. I dread the day that I read "Coin calls from this telephone are carried by the US Sprint PublicFON service.")) Andrew Boardman amb@cs.columbia.edu (but if you really have to, ab4@cunixc will work from bitnet)