gnd@tetons.UUCP (Greg Darnell) (05/17/89)
I would like some advice on ways to set up a phone so that the
outgoing calls can be restricted to certain numbers or ranges of
numbers. My wife runs a horse boarding stable, we want to have a phone
in the barn for emergencies etc., but don't want to hassle with people
making "free" long distance calls on our phone. Our friendly telco
USWest has such a service for a low monthly fee but an outrageous setup
fee of about $370.
The only idea I have come up with so far is to buy a cheapie
programmable phone, program numbers such as 911, vet., etc. and then
install a key switch to disable the dialing keys. Are there phones
that can do what I want already? Is there such a thing as a
do-it-yourself pay phone where you can program the fees for different
exchanges to be called, and then just use it on your own normal phone
line, or do you have to go through the phone company? Any ideas and/or
parts sources would be welcomed.
Thanks
Greg
--
Greg Darnell Amdahl Corporation 143 N. 2 E., Rexburg, Idaho 83440
UUCP:{ames,decwrl,sun,uunet}!amdahl!tetons!gnd (208) 356-8915
INTERNET: gnd@tetons.idaho.amdahl.comcah@genrad.com (Chris A. Heitmann) (05/18/89)
I don't know about phones that can already do what you want. Just want to
offer a bit of advice. If you do what you say, disable the keypad, they
can still make calls anywhere they want with a hand held dialer (assuming
that you have tone service). So watch out for that.
Chris
-----
Chris Heitmann "Check's in the Email..."
cah@genrad.com or {decvax,husc6,mit-eddie}!genrad!cahmaa@nbires.nbi.com (Mark Armbrust) (05/18/89)
I did't see the beginning of this thread, so this might have been mentioned, but most phone lines can be "dialed" using the the hook switch (the buttons the handset sits on). Back when we were in high school, the math lab had dial locks on the phones in an attempt to stop unauthorized use of the computer (dial-up acoustic coulped modems hooked to ASR-33's, it was a while ago :-). We got very good at calling out on these phones without dialing! Mark Armbrust maa@nbires.nbi.com maa@nbires.UUCP
henry@utzoo.uucp (Henry Spencer) (05/18/89)
In article <21001@genrad.UUCP> cah@genrad.UUCP (Chris A. Heitmann) writes: >...If you do what you say, disable the keypad, they >can still make calls anywhere they want with a hand held dialer (assuming >that you have tone service)... And if they're deft, they can make calls anywhere they want even if you *don't* have tone service, by rapidly pulsing the hookswitch (the switch that distinguishes between "on hook" and "off hook", often by having the receiver's weight rest on it when "on hook"). All a conventional phone dial does as it returns after you've turned it to a number is to open and close the circuit repeatedly. Phone exchanges are tolerant enough that you can do the same thing manually, at least on a standard Bell phone. (Might not work on electronic ones.) -- Subversion, n: a superset | Henry Spencer at U of Toronto Zoology of a subset. --J.J. Horning | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
tc@diablo.amd.com (Tom Crawford) (05/18/89)
>>...If you do what you say, disable the keypad, they >>can still make calls anywhere they want with a hand held dialer (assuming >>that you have tone service)... > >And if they're deft, they can make calls anywhere they want even if you >*don't* have tone service, by rapidly pulsing the hookswitch (the switch >that distinguishes between "on hook" and "off hook", often by having the I know from first hand experience that you can "dial" O(perator) by pulsing the hookswitch. Then you can place an operator-assisted call anywhere you like... Tom Crawford
gnd@tetons.UUCP (Greg Darnell) (05/19/89)
In article <1989May18.042535.9003@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > In article <21001@genrad.UUCP> cah@genrad.UUCP (Chris A. Heitmann) writes: > >...If you do what you say, disable the keypad, they > >can still make calls anywhere they want with a hand held dialer (assuming > >that you have tone service)... > > And if they're deft, they can make calls anywhere they want even if you > *don't* have tone service, by rapidly pulsing the hookswitch (the switch I agree there are many ways to get around disabling the dialing method. Somebody with a Dick Tracy (Casio) phone dialing watch, or a little dialer, or with fast fingers, or with a computer with a modem with an external speaker they hold up to the phone. Hell, why not plug in your own phone if it's modular! My point, which I should have made clear in the first posting, was to stop the casual phone thief, just as an auto or home burglar alarm may only deter the amateur burglar. And to do this for less than $370 plus $5/month. Unfortunately, our telco does not offer local-only service; even if you have no long distance carrier, in-state calls (which can be just as expensive as long distance) can still be made. Any new ideas? -- Greg Darnell Amdahl Corporation 143 N. 2 E., Rexburg, Idaho 83440 UUCP:{ames,decwrl,sun,uunet}!amdahl!tetons!gnd (208) 356-8915 INTERNET: gnd@tetons.idaho.amdahl.com
rar@hplvli.HP.COM (Ray Robertson) (05/19/89)
In some areas the polarity of the line switches on any toll call. Putting a diode in series with the phone line will terminate a toll call while allowing local calls. Cost about $.05.
dclaar@hpcupt1.HP.COM (Doug Claar) (05/19/89)
I've seen references to devices that you can hook up between the phone that can be programmed to only allow certain numbers, with passwords & such. I'm sorry I can't provide more detail--this came up when 976 blocking was being discussed some time ago. You'd probably be better off looking in comp.dcom.telecom (a moderated group). That's where them gnarly phone dudes hang out... :-) Mail your question to telecom@eecs.nwu.edu, and watch there for a couple of days. You should get answer(s). Doug Claar HP Computer Systems Division UUCP: mcvax!decvax!hplabs!hpda!dclaar -or- ucbvax!hpda!dclaar ARPA: dclaar%hpda@hplabs.HP.COM
tomb@hplsla.HP.COM (Tom Bruhns) (05/19/89)
> gnd@tetons.UUCP (Greg Darnell) writes: >In article <1989May18.042535.9003@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: >> In article <21001@genrad.UUCP> cah@genrad.UUCP (Chris A. Heitmann) writes: >> >...If you do what you say, disable the keypad, they >> >can still make calls anywhere they want with a hand held dialer (assuming >> >that you have tone service)... >> >> And if they're deft, they can make calls anywhere they want even if you >> *don't* have tone service, by rapidly pulsing the hookswitch (the switch > >I agree there are many ways to get around disabling the dialing method. >Somebody with a Dick Tracy (Casio) phone dialing watch, or a little >dialer, or with fast fingers, or with a computer with a modem with an >external speaker they hold up to the phone. Hell, why not plug in your >own phone if it's modular! My point, which I should have made clear in >the first posting, was to stop the casual phone thief, just as an auto >or home burglar alarm may only deter the amateur burglar. And to do >this for less than $370 plus $5/month. Unfortunately, our telco does >not offer local-only service; even if you have no long distance carrier, >in-state calls (which can be just as expensive as long distance) can >still be made. > Any new ideas? > >-- > Greg Darnell Amdahl Corporation 143 N. 2 E., Rexburg, Idaho 83440 > UUCP:{ames,decwrl,sun,uunet}!amdahl!tetons!gnd (208) 356-8915 > INTERNET: gnd@tetons.idaho.amdahl.com >---------- Well, this is something I would like to do also (as part of a more grandiose phone plan). So far my thoughts lead to a project that is probably bigger than $370, unless it could be done in volume. If I do it, it will be a labor of love. But your posting got me thinking about a simpler solution that may work for you. Here it is: Put a box in series with the phone line. This box eavesdrops on the line (perhaps through a current-sense transformer, so it doesn't have to worry about ringing voltage so much). If it hears a tone-pair, it opens up the line long enough to disconnect. It also has a set of buttons on it that actuate an autodialer that is not listened to by the box; the autodialer is programmed with the selected phone numbers. It should be possible to build such a beast for a parts cost under $50. (It could probably even be built to extend on-hook breaks enough that it would be impossible to dial out with hook depressions.) You can probably think of how this could be extended to dial any local prefix, then allow an arbitrary final four digits. That would complicate things considerably, I suspect, but could still be done cheaper than $370. Of course, it's up to you to insure this thing meets appropriate regulations... Tom Bruhns tomb%hplsla@hplabs.hp.com
mjr@hpcvca.CV.HP.COM (Mark Reed) (05/20/89)
Possibilities (choose or discard according to your situation) Cordless phone - carry it with you when you go out to the barn A hidden switch to disable the phone. Or, get two phones. Rig one up to be ring only so you can be aware of incoming calls, and use the hidden switch trick so the other is enabled only when you want to answer an incoming call or make an outgoing call. You can hide the switch most anywhere along the wire as long as it is not between the phone company and the "ring only" phone. You could be real tricky and automatically enable the regular phone on incoming calls - detect the ring signal and kick in a relay. These ideas don't limit the outgoing calls to certain numbers, but may solve your unauthorized use problem. They are, of course, worth what you paid for them. Mark
albaugh@dms.UUCP (Mike Albaugh) (05/20/89)
From article <920001@hplvli.HP.COM>, by rar@hplvli.HP.COM (Ray Robertson): > > In some areas the polarity of the line switches on any toll call. > Putting a diode in series with the phone line will terminate a toll > call while allowing local calls. Cost about $.05. It is much more common for polarity to reverse on any _completed_ (i.e. answered) call. The fact that you do not get reversal on, e.g. (312)555-1212 or "your call cannot be completed as dialed" is accomplished by _not_ indicating "off hook", while allowing conversation. In any case, battery reversal is rare and getting moreso, since it makes it too easy on people who would otherwise have to pay a telco for billing or toll- restriction :-( I would suggest moving this to comp.dcom.telcom, where toll restrictors are discussed as a regular feature. | Mike Albaugh (albaugh@dms.UUCP || {...decwrl!turtlevax!}weitek!dms!albaugh) | Atari Games Corp (Arcade Games, no relation to the makers of the ST) | 675 Sycamore Dr. Milpitas, CA 95035 voice: (408)434-1709 | The opinions expressed are my own (Boy, are they ever) ( I do not now, nor have I ever, worked for a telco, but I uhhh, _studied_ them extensively in my long-ago youth....)
bote@csense.UUCP (John Boteler) (05/21/89)
From article <778@tetons.UUCP>, by gnd@tetons.UUCP (Greg Darnell): > ...My wife runs a horse boarding stable, we want to have a phone > in the barn for emergencies etc., but don't want to hassle with people > making "free" long distance calls on our phone. Why don't you just install a coin station and be done with it? -- Bote uunet!cyclops!csense!bote {mimsy,sundc}!{prometheus,hqda-ai}!media!cyclops!csense!bote
timk@egvideo.UUCP (Tim Kuehn) (05/22/89)
In article <5170029@hplsla.HP.COM> tomb@hplsla.HP.COM (Tom Bruhns) writes: > >Well, this is something I would like to do also (as part of a more >grandiose phone plan). So far my thoughts lead to a project that is >probably bigger than $370, unless it could be done in volume. If I >do it, it will be a labor of love. But your posting got me thinking >about a simpler solution that may work for you. Here it is: > >Put a box in series with the phone line. ..technical details deleted.... > >Tom Bruhns >tomb%hplsla@hplabs.hp.com Actually - a design for something like this is pretty simple. I'm putting something together that does this same kind of function (plus a good number of other bells and whistles) and can suggest the following (for any hobbyist/HW guy out there). Quite simply, what you want is a pulse/code decoder, a DTMF decoder, a on/off hook relay (for the pulse/code decoder and to detect off/on hook) a cutoff relay, and a uC with enough EPROM for the SW to decode what's going on the line to hang to phone up if more than seven digits are dialed (or a "0" by itself, or other 'illegal' type phone call). Basically you take interface the DTMF decoder and the pulse count/decode lines to the telco, program the uC to only allow seven digit codes to go through and watch for an intial "0" immediately after on-hook is detected, and that's it! Including a PS, chips, and other miscellany, it should run between $75 - $100 US to build one from scratch. The hardest part would be programming the uC. (I'm using an 68HC05C8 for my project). Hope this gives some idea(s) for actual construction of such a device. +-----------------------------------------------------------------------------+ |Timothy D. Kuehn timk@egvideo | |TDK Consulting Services !watmath!egvideo!timk | |871 Victoria St. North, Suite 217A | |Kitchener, Ontario, Canada N2B 3S4 (519)-741-3623 | +-----------------------------------------------------------------------------+
tsn@neoucom.UUCP (Tom Napoletano) (05/22/89)
There are many toll restrictors on the market. A good example is the TELEDIAL ted-td-5000r. This dialer is tone pulse selectable, restricts 0 or 1 first digit, circuit to prevent hookflash, line powered and 9 three digit code memory restriction. The design is a replacement keypad that you install in place of the old pad. There are line based versions that function in the same manner if the line cord security bothers you. My local vendor is FAMOUS TELEPHONE SUPPLY AKRON OHIO 216-762-8811 (ohio? 800-321-9122)
joe@mojave.UUCP (Joe Talbot) (05/23/89)
The diode trick won't work in most (almost all) areas anymore. Portable tone dialers are everywhere now, so turning off the pad is useless, and some people actually know about hookswitch dialing (wow). Call NTD at (800) 426-1024 and buy one of these: HY-ULT1A- programmable, can block specific prefixes and area codes (900 and 976 for example), line powered, tone and pulse, very small. Allows toll calls to authorized users with access code (changable). Should be wired in series with all phones you wish to restrict. Wholesale (pretend to be a dealer) price $59.98 NTD also stocks many nice, cheap phone systems and accessories. My personal favorites being the Panasonic KX-T 61610, KX-T 30810 and KX-T 123211 hybrid key systems/PBXs. You can plug all your single line stuff into them and dial 9 to get out, transfer calls and other PBX type stuff including toll restriction, music on hold, speed calling, forwarding, conferencing and a printed record of all calls, durations, etc. Cheap! Did I wander? -- joe@mojave "I really hate my dumb job." "People are always telling me what a great (gag!) voice I have."
tsn@neoucom.UUCP (Tom Napoletano) (05/23/89)
COCOT's are not cheap and are not easy. There are many rules and regs that the state PUC's control. Paystations themselves are not cheap and easy. Without a minimum number of calls, most private payphone people would not touch the service. Research this well before you jump into the field.
iws@rayssdb.ray.com (Ihor W. Slabicky) (06/01/89)
In article <244@csense.UUCP>, bote@csense.UUCP (John Boteler) writes: > From article <778@tetons.UUCP>, by gnd@tetons.UUCP (Greg Darnell): > > ...My wife runs a horse boarding stable, we want to have a phone > > in the barn for emergencies etc., but don't want to hassle with people > > making "free" long distance calls on our phone. > > Why don't you just install a coin station > and be done with it? Buy a touchtone phone, take out or disconnect the touchtone pad, and hook up the phone to the line. You'll be able to receive all the calls you want, but can't dial out.
dmt@PacBell.COM (Dave Turner) (06/02/89)
In article <2437@rayssdb.ray.com> iws@rayssdb.ray.com (Ihor W. Slabicky) writes: >In article <244@csense.UUCP>, bote@csense.UUCP (John Boteler) writes: >Buy a touchtone phone, take out or disconnect >the touchtone pad, and hook up the phone to the >line. You'll be able to receive all the calls >you want, but can't dial out. But what happens if I go to Radio Shack and buy a "Low-Cost Pocket Tone Dialer" for $14.95? Won't the tones still dial out-going calls? -- Dave Turner 415/542-1299 {att,bellcore,sun,ames,decwrl}!pacbell!dmt
erk@americ.UUCP (Erick Parsons) (06/03/89)
>Buy a touchtone phone, take out or disconnect >the touchtone pad, and hook up the phone to the >line. You'll be able to receive all the calls >you want, but can't dial out. >>But what happens if I go to Radio Shack and buy a "Low-Cost Pocket >>Tone Dialer" for $14.95? >>Won't the tones still dial out-going calls? Cheapest way: Lose the phone bill. Takes about 2 months though :-) -- ------------------ // -----------Cut-Here---------------------------------- Erick Parsons // Words for the wise: *If it works don't fix it.* Sacramento Ca // mail to: ...pacbell!sactoh0!americ!erk ------------- \\// --------------------------------------------------------
snoopy@sopwith.UUCP (Snoopy) (06/04/89)
In article <2019@egvideo.UUCP> timk@egvideo.UUCP (Tim Kuehn) writes: | on the line to hang to phone up if more than seven digits are dialed (or | a "0" by itself, or other 'illegal' type phone call). Before blocking access to the operator, consider the possibility of someone needing to be able to call for police/fire/ambulance/etc from that phone. 911 (if available) *may* take care of these, but it's worth thinking about. Unanticipated problems have a way of cropping up. _____ .-----. /_____\ Snoopy ./ RIP \. /_______\ qiclab!sopwith!snoopy | | |___| parsely!sopwith!snoopy | tekecs | |___| sun!nosun!illian!sopwith!snoopy |_________| "I *am* the next man!" -Indy
ron_b@apollo.COM (Ronald Buttiglieri) (06/07/89)
In article <4814@ptsfa.PacBell.COM> dmt@PacBell.COM (Dave Turner) writes: >In article <2437@rayssdb.ray.com> iws@rayssdb.ray.com (Ihor W. Slabicky) writes: >>In article <244@csense.UUCP>, bote@csense.UUCP (John Boteler) writes: >>Buy a touchtone phone, take out or disconnect >>the touchtone pad, and hook up the phone to the >>line. You'll be able to receive all the calls >>you want, but can't dial out. > >But what happens if I go to Radio Shack and buy a "Low-Cost Pocket >Tone Dialer" for $14.95? > >Won't the tones still dial out-going calls? > ***We interrupt this thread for some trivial bit of information**** I don't know how many know this (for all I know, everyone does :^) but a very simple way to make any TouchTone (tm?) phone (note, if it's pulse switchable, all bets are off!) not able to dial out, simply reverse the red and green wires (easiest to access them in the wall jack). You will hear a dialtone when you lift the handset, but when you press the buttons, you don't loose the dial- tone. Actually, I haven't tried it with the more modern phones (last I did this was 3 or 4 years ago), I don't know if the newer ones are still affected. If someone finds that they are not, please let me (maybe the net, too) know. Ron ***We now return to our regularly scheduled threads ***
ijk@cbnewsh.ATT.COM (ihor.j.kinal) (06/07/89)
In article <2437@rayssdb.ray.com>, iws@rayssdb.ray.com (Ihor W. Slabicky) writes: > > Buy a touchtone phone, take out or disconnect > the touchtone pad, and hook up the phone to the > line. You'll be able to receive all the calls > you want, but can't dial out. Yes, but a really determined person could: 1). By a tone-generator dialer [e.g. from Radio Shack for perhaps $20]. [I wonder if you could install a filter to eliminate the tones???] 2). Even use switch-hook dialing [difficult, but I guess all they would have to do is get the operator. If you really want to be secure, it might be difficult. Perhaps for some dollars, the phone company could provide a non-outgoing line. Perhaps this should really be in the telecom section. Ihor Kinal P.S. Although I work at Bell Labs, I'm a software person. P.P.S. Nice to see another Ihor on the net.
makela@tukki.jyu.fi (Otto J. Makela) (06/08/89)
In article <43afec9f.16321@apollo.COM>, ron_b@apollo.COM (Ronald Buttiglieri) says: |I don't know how many know this (for all I know, everyone does :^) but a |very simple way to make any TouchTone (tm?) phone (note, if it's pulse switchable, |all bets are off!) not able to dial out, simply reverse the red and green |wires (easiest to access them in the wall jack). You will hear a dialtone when |you lift the handset, but when you press the buttons, you don't loose the dial- |tone. | |Actually, I haven't tried it with the more modern phones (last I did this was |3 or 4 years ago), I don't know if the newer ones are still affected. If |someone finds that they are not, please let me (maybe the net, too) know. | |Ron Well, most high-class phones over here have a full rectifier bridge across the phone line before doing anything else with it. That way it doesn't matter which way the phone meets the line... Otto J. Makela, University of Jyvaskyla InterNet: makela@tukki.jyu.fi, BitNet: MAKELA_OTTO_@FINJYU.BITNET BBS: +358 41 211 562 (V.22bis/V.22/V.21, 24h/d), Phone: +358 41 613 847 Mail: Kauppakatu 1 B 18, SF-40100 Jyvaskyla, Finland, EUROPE "In the week before their departure to Arrakis, when all the final scurrying about had reached a nearly unbelievable frenzy, an old crone came to visit the mother of the boy, Paul." - Frank Herbert, Dune
hughes@math.Berkeley.EDU (Eric Hughes) (06/17/89)
In article <43afec9f.16321@apollo.COM>, ron_b@apollo (Ronald Buttiglieri) writes: > >I don't know how many know this (for all I know, everyone does :^) >but a very simple way to make any TouchTone (tm?) phone ... not able >to dial out, simply reverse the red and green wires (easiest to >access them in the wall jack). You will hear a dialtone when you lift >the handset, but when you press the buttons, you don't loose the >dial- tone. > >Actually, I haven't tried it with the more modern phones (last I did this was >3 or 4 years ago), I don't know if the newer ones are still affected. If >someone finds that they are not, please let me (maybe the net, too) know. This is true of older Western Electric dial pads, which were engineered not to produce tones were the line polarity was reversed. I believe the name for it was something like Tone Gaurd. From what I understand, before the phone company allowed subscriber line equipment, this polarity reversal was how they enforced touch tone availability. (Don't believe me, though.) I haven't come across a recent phone that has this characteristic, however. Eric Hughes hughes@math.berkeley.edu ucbvax!math!hughes
rusty@cadnetix.COM (Rusty Carruth) (06/20/89)
In article <3237@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes:
....
-> Enforcement of DTMF service availability was performed solely in
->the central office, and was accomplished as follows:
->
->1. In the comparatively few SxS CO's which were converted to DTMF
-> ...., only DTMF customers were assigned to linefinder
-> groups so equipped.
->
->2. In #1 and #5 Xbar CO's the DTMF class of service was effected by
-> assigning DTMF customers to only certain line link frames ...
->
->3. In ESS CO's, from day one, DTMF availability was always a parameter
-> specification for every subscriber line, and the denial of service
-> was therefore accomplished in software.
->
-><> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp
Hi, Larry. My only question is why then do some people have DTMF
access who never asked nor paid for it? Software bug? :-)
----------
Rusty Carruth UUCP:{uunet,boulder}!cadnetix!rusty DOMAIN: rusty@cadnetix.com
Daisy/Cadnetix Corp. (303) 444-8075\ 5775 Flatiron Pkwy. \ Boulder, Co 80301
Radio: N7IKQ 'home': P.O.B. 461 \ Lafayette, CO 80026brian@ucsd.EDU (Brian Kantor) (06/23/89)
In applications where there were mixed classes of service on a small keyset system, ThePhoneCo would occasionally use a combination of reversed polarity and polarity-guard widgets to allow some phones to dial and other not. In particular, a friend had an office with attached living quarters wherein he wanted to be able to have his residence phone as one of the line appearances on his 5-line keyset phones. TPC installed the residence line with tip and ring reversed so that it wasn't possible to dial out on the flat-rate residence line from the business touchtone phones (which would have avoided paying for business message units). The keyset inside the house had a polarity guard in it so that it could dial on any of the lines. Polarity guards are also one of the main contributors of interference to telephone lines from ham radio signals. In several cases the amount of RF induced into the neighbor's inside wiring was sufficiently small that only the phone with the polarity guard bridge rectifier had problems. Removing it cured the problem. - Brian
lbechtle@uceng.UC.EDU (laurie bechtler) (06/24/89)
In article <25535@agate.BERKELEY.EDU>, hughes@math.Berkeley.EDU (Eric Hughes) writes: > >I don't know how many know this (for all I know, everyone does :^) > >but a very simple way to make any TouchTone (tm?) phone ... not able > >to dial out, simply reverse the red and green wires (easiest to > >access them in the wall jack). You will hear a dialtone when you lift > >the handset, but when you press the buttons, you don't loose the > >dial- tone. > I haven't come across a recent phone that has this characteristic, however. > I just moved into a new apartment, and for a week I couldn't dial out (the dial tone wouldn't break) but I could receive calls. I didn't want to issue a repair order until I could take the phone in to be checked out. Finally when I called in to make sure the phone co. had completed service installation, the woman on the line told me to switch the red and green wires. It worked. I dunno why it worked the opposite way for the previous tenant. Also I dunno if they regularly suggest that trick or if sometimes they charge you for a service visit to "fix" the line...I'm half tempted to not pay for a week of service.
wolfgang@mgm.mit.edu (Wolfgang Rupprecht) (06/28/89)
In article <8522@cadnetix.COM> rusty@cadnetix.COM (Rusty Carruth) writes: >My only question is why then do some people have DTMF >access who never asked nor paid for it? Software bug? Yes. In Boston, Me Belle never seems to turn off the touch-tone service in the newer ESS exchanges. We once discovered this fact after buying the first switchable touch-tone/pulse phone. After a month of use we got a "strange" call from a person at Ma Belle. She wanted me to dial a "0". Unfortunately I had answered on the touch-tone phone, the dial-mode switch for it was internal, and I sure couldn't switch-hook 10 pulses accurately enough to please the *test-equipment*. What did I do? Yell, "Sorry, something's burning in the kitchen!", and hang up. When she called back I was naturely waiting by the dial-phone. The conversation continued: Bell: "We have been noticing that you have a touch-tone phone. You aren't paying for touch-tone service." Me: "How much extra is that per month?" Bell: "56 cents" Me: "Ok, i'll take it." Bell: "Theres also a 20 dollar installation fee." At this point the conversation got pretty silly. I told them I obviously didn't need any installation at all, and I certainly wouldn't pay for any. It turned out that the internal red tape prevented them from charging me for the 56 cents WITHOUT charging for the installation fee. (Then there is always the time a bored friend of mine called up Ma Belle and asked why it costs more to call western Mass. then just over the border. The answer is, of course, federal regulations. The harried bell employee claimed that it was easier to send signals further and mumbled something about the speed of light.) ;-) -wolfgang --- Wolfgang Rupprecht ARPA: wolfgang@mgm.mit.edu (IP 18.82.0.114) TEL: (703) 768-2640 UUCP: mit-eddie!mgm.mit.edu!wolfgang
larry@kitty.UUCP (Larry Lippman) (06/29/89)
In article <8522@cadnetix.COM>, rusty@cadnetix.COM (Rusty Carruth) writes: > Hi, Larry. My only question is why then do some people have DTMF > access who never asked nor paid for it? Software bug? :-) > ->1. In the comparatively few SxS CO's which were converted to DTMF > -> ...., only DTMF customers were assigned to linefinder > -> groups so equipped. Very few SxS CO's were actually converted, and interesingly enough most of the conversion apparatus which I am aware of in BOC CO's was manufactured by ITT, and not WECO. In any event, with this type of apparatus there was no class of service wiring option other than physical linfinder assignment. The only way that "free" DTMF service might have been provided was: (1) someone screwed up and assigned the customer line to a linefinder group equipped with the DTMF register-sender converters; or (2) lines were getting scarce in the CO, and the DTMF linefinder groups were the only ones available. > ->2. In #1 and #5 Xbar CO's the DTMF class of service was effected by > -> assigning DTMF customers to only certain line link frames ... The most common cause of "free" DTMF service was line link frame scarcity, which required assignment to LLF verticals that were recognized by the marker as permitting DTMF service. As in the SxS CO's mentioned above, there was no class of service wiring option on a line by line basis other than LLF assignment. > ->3. In ESS CO's, from day one, DTMF availability was always a parameter > -> specification for every subscriber line, and the denial of service > -> was therefore accomplished in software. Ah, now THIS is software! In "early" ESS years, a parameter specification screwup was the only cause of "free" DTMF service. In more recent years, there has been a policy in some BOC areas to provide everyone with DTMF service, and use a traffic monitoring program to see WHO USED IT and was NOT PAYING FOR IT. Those who were "caught" using it were sent letters offering to allow the service to continue for a monthly fee, or to have it disabled if the customer did not wish to pay. In this latter case, allowing "free" service was intentional and somewhat of a marketing ploy. <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {hplabs|utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"
larry@kitty.UUCP (Larry Lippman) (07/22/89)
In article <25535@agate.BERKELEY.EDU>, hughes@math.Berkeley.EDU (Eric Hughes) writes: > >I don't know how many know this (for all I know, everyone does :^) > >but a very simple way to make any TouchTone (tm?) phone ... not able > >to dial out, simply reverse the red and green wires (easiest to > >access them in the wall jack). You will hear a dialtone when you lift > >the handset, but when you press the buttons, you don't loose the > >dial- tone. DTMF dial telephones manufactured within the past 15 or so years generally work with either line polarity. > This is true of older Western Electric dial pads, which were engineered > not to produce tones were the line polarity was reversed. I believe the > name for it was something like Tone Gaurd. From what I understand, before > the phone company allowed subscriber line equipment, this polarity > reversal was how they enforced touch tone availability. (Don't believe > me, though.) Sorry, I don't believe you. :-) The original DTMF dial design was an _extremely_ clever design which employed only one germanium transistor with a dual resonant tank circuit to simultaneously oscillate at two frequencies. This was a "minimum component" design, and Bell Labs engineers obviously deemed it unnecessary to provide a full-wave bridge rectifier for use on either line polarity. The low-cost, minimum component design goal was the sole reason why the DTMF dial was polarity-sensitive. In later years, Western Electric offered an applique consisting of a full-wave rectifier and a couple of resistors on a small circuit board to make the 35-type DTMF dials polarity-insensitive. This applique was called a "polarity guard", and had a P-number designation (which I have long forgotten). Enforcement of DTMF service availability was performed solely in the central office, and was accomplished as follows: 1. In the comparatively few SxS CO's which were converted to DTMF service (through shared register-senders inserted between linefinder and first selector), only DTMF customers were assigned to linefinder groups so equipped. 2. In #1 and #5 Xbar CO's the DTMF class of service was effected by assigning DTMF customers to only certain line link frames (or in some cases only certain verticals within a LLF) which were associated by the marker with only certain originating registers equipped with DTMF receivers. 3. In ESS CO's, from day one, DTMF availability was always a parameter specification for every subscriber line, and the denial of service was therefore accomplished in software. <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {hplabs|utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"