Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!bellcore!texbell!vector!telecom-gateway From: dplatt@coherent.com (Dave Platt) Newsgroups: comp.dcom.telecom Subject: Re: Wrong Numbers With Nobody Talking Message-ID:Date: 22 Sep 89 19:04:07 GMT Sender: news@vector.Dallas.TX.US Organization: Coherent Thought Inc., Palo Alto CA Lines: 69 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 405, message 3 of 5 In article you write: > > I moved a couple of months back, and I've had a weird problem since then. I > get lots of wrong numbers. Some of them are the normal "Is Joe there?" and > I say no and the person goes away. But the vast majority of them have no > voice at all. I pick up the phone, hear a faint 'clickclickclick' in the > background, and nothing happens, so I hang up. On my answering machine, > I don't get any message either; just those faint sounds. I thought perhaps > it was people calling me from a computer, but then I'd hear a modem tone, > wouldn't I? ... No, you would very probably not hear a modem tone, if a modem were dialing you. With most modems in use today, the _answering_ modem is responsible for sending the first tone, after it goes off-hook. The type of answer-tone transmitted identifies the protocol(s) that the answering modem is able to use. The originating modem "hears" the answer tone, chooses a protocol, and begins transmitting its carrier. The answering modem "hears" the originator's carrier, stops sending the answer-tone, and begins transmitting its carrier. If, on the other hand, the originating modem never "hears" an answer tone, it will never "know" that the call has been answered, and will simply disconnect after 30 seconds or a minute and report a "NO CARRIER" situation to its pilot. So, a local- or long-distance call with nothing but silence on the other end could very well be from a modem. There are a couple of relatively common ways that you can end up with numerous calls of this type: 1) Somebody at a specific computer site has misprogrammed one of their outdial modems... for example, transposing a digit in the phone-number used to contact one of their "neighbor" systems. If this has occurred, most of all of the calls you receive will be from the same exchange (either all local, or all long-distance), and there's a fairly good chance that they'll stop after a few weeks. The sysadmin of the offending system will (probably) notice that a large number of calls aren't getting through, will figure out the problem, and will correct his/her dialer-file. 2) The phone numbers for computer-hobbyist "bulletin board" systems tend to be passed around between personal-computer users. Bulletin-board systems tend to come and go fairly frequently... the survival time for a BBS tends to be measured in months. If the phone number for a BBS is circulated widely, then there may be literally thousands of people who have a copy of the number. If that BBS then goes out of service (for example, if its owner/sysop moves), then the phone number will often be given out to someone who is having phone service installed. Subsequently, the new "owner" of this number will receive many, MANY phone-calls from computer hobbyists who aren't aware that the BBS is out of service. I rather suspect that you're facing the second of these situations, since you seem to be receiving calls from both local and long-distance sources. The only really effective solution of which I'm aware is to ask the phone company to give you a different phone number. They'll probably charge you for the service-change, since they can legitimately argue that the problem is not _their_ fault. Dave Platt FIDONET: Dave Platt on 1:204/444 VOICE: (415) 493-8805 UUCP: ...!{ames,sun,uunet}!coherent!dplatt DOMAIN: dplatt@coherent.com INTERNET: coherent!dplatt@ames.arpa, ...@uunet.uu.net USNAIL: Coherent Thought Inc. 3350 West Bayshore #205 Palo Alto CA 94303 [Moderator's Note: Some telcos, like Illinois Bell, will change a subscriber's number once for free, if the subscriber complains of receiving nuisance or obscene calls. The original correspondent's complaint would probably fit in this category. PT]