TELECOM Digest Wed, 1 Jun 94 12:34:00 CDT Volume 14 : Issue 262 Inside This Issue: Editor: Patrick A. Townson Re: Annoying COCOT Problem (Mark E. Daniel) Re: Annoying COCOT Problem (Steve Kass) Re: How Do You Simulate Telco Battery Voltage? (Paul Jonathan E. Go) Re: How Do You Simulate Telco Battery Voltage? (David B. Thomas) Re: DTMF Decoding Help Needed (David B. Thomas) Re: RBOCS & Video Remote Learning in Schools? (Bob Schwartz) Re: Cordless Phone Wanted With Ten Mile Range (David B. Thomas) Re: Cordless Phone Wanted With Ten Mile Range (Tawfig Al-Rabiah) Re: Book Review: "Internet: Mailing Lists" by Hardie/Neou (Nick Sayer) Re: DS3 to Fiber Optic Convertor (Paul J. Zawada) Re: Average Data Speed of Wire Telegraphy Wanted (Bill Mayhew) Re: Misdialed Numbers (Mike Pollock) Re: Sprint "Combined Billing" Error (Mike Pollock) Re: Annoyance Calls From Answering Machine (animallib@aol.com) Re: Annoyance Calls From Answering Machine (Gary D. Shapiro) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and GEnie. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available at no charge to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: 9457-D Niles Center Road Skokie, IL USA 60076 Phone: 708-329-0571 Fax: 708-329-0572 ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. For a copy of a helpful file explaining how to use the information service, just ask. ************************************************************************* * TELECOM Digest is partially funded by a grant from the * * International Telecommunication Union (ITU) in Geneva, Switzerland * * under the aegis of its Telecom Information Exchange Services (TIES) * * project. Views expressed herein should not be construed as represent-* * ing views of the ITU. * ************************************************************************* Additionally, the Digest is funded by gifts from generous readers such as yourself who provide funding in amounts deemed appropriate. Your help is important and appreciated. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- Date: Tue, 31 May 1994 04:16:06 EST From: mark@legend.akron.oh.us (Mark E Daniel) Subject: Re: Annoying COCOT Problem You could just use an external tone dialer. They don't disable the mouth piece. :) I believe this is done to stop hackers and the like. But all it really does is annoy honest people since a hacker is probably going to have a tone dialer or a tape recorder anyway. I also find it annoying that the COCOT (what does that stand for anyway) phones have these little computers in them that verify what I'm dialing. Only problem is that they are not kept up-to-date. And what's the point of verifing my dialing anyway ... I've never had it deny an 800 number. But then I've never tried a 900 number. :) Maybe that's it. Also within the last ten months GTE made a deal with Ameritech to allow me to use my Ameritech calling card in GTE-land for local calls except that I get billed 10 cents extra plus three cents tax for that one call. :). Oh, I HATE non-Ameritech payphones. I stick my tounge out at them and run ... :) Mark E Daniel (Loving SysOp of The Legend BBS) Inet: mark@legend.akron.oh.us [TELECOM Digest Editor's Note: COCOT = 'Customer Owned, Coin Operated Telephone'. Or perhaps the correct phrase is 'Coin Operated, Customer Owned Telephone'. For all the rotten things people have had to say about the Telephone Company over the years, you sure can't beat their coin phone service, eh? At least not when compared to the others. PAT] ------------------------------ Subject: Re: Annoying COCOT Problem From: skass@drunivac.drew.edu (Steve Kass) Date: 1 Jun 94 11:25:52 EDT Organization: Drew Univ Academic Computing In TELECOM Digest Volume 14 : Issue 260 Stu Jeffery writes: > In TELECOM Digest V14 #257, Darren Griffitsh writes: >> Basically, if I call my voice mail system to check for messages the >> phone frequently cuts out the keypad, disabling DTMF tones ... > Why don't you try a pocket dialer from Radio Shack, etc. A pocket dialer may not work. The technology is in place to detect DTMF whether or not it is generated by the instrument. This is not solely a COCOT problem, either. NYTel and many other BOCs routinely disable the keypad, and even disconnect calls, after some "excessive" number of tones, under the guise of the war against drugs. My belief from hazy information provided me by AT&T, NYTel, and various regulatory organizations is that local law enforcement officials work with the telcos to discourage the use of voice mail and beeper services in certain parts of certain cities at certain times. So far as I have been able to gather, the telcos are free to do this, or at least no regulatory agency seems to care that they do this. I do wonder, however, how they can get away with detecting DTMF generated outside the instrument and disconnecting a call as a result. Is this any different from disconnecting a call when vulgar words are spoken? Anyone care to speculate? For now, the best solution is to ask your long distance carrier to remove the charges for calls that have been disconnected. AT&T will do so, and perhaps if this happens often enough, they will get annoyed enough to help put pressure on the BOCs to stop this nonsense. Steve Kass/ Math & CS/ Drew U/ Madison NJ 07940/ 201-514-1187 skass@drunivac.drew.edu ------------------------------ From: pj@ugcs.caltech.edu (Paul Jonathan E. Go) Date: Tue, 31 May 1994 23:21:22 -0700 Subject: Re: How Do You Simulate Telco Battery Voltage? Organization: California Institute of Technology, Pasadena, CA > ... The ringing voltage will wake up the card, but upon waking if it > does not find that current from the series loop on there it will > disconnect and go back to sleep ... Pat -- Would you know how the card detects the series loop current? I'm building a patch through box, and it would be nice if the box could hang up when everyone else has hung up. Paul Jonathan E. Go Caltech MSC 1028 213 344 7275 Pasadena CA 91126 pj@cco.caltech.edu [TELECOM Digest Editor's Note: Off hand I do not know the technical aspects of the card itself; only what it will and won't do. Remove the current from the line and the card quits. That's one reason why in my opinion anyone using such a card in a public voicemail applica- tion is advised to get ground start lines from telco. That way once the calling party hangs up, the current is gone; no risk of (for example) the card getting hung somehow, coming back into service and finding dialtone on the line and doing something ugly you don't want it to do, like making outgoing 900 calls for someone hanging on the other side of it. To answer your question, the easy answer would be just make sure the current is not there between calls. No current, no action. PAT] ------------------------------ From: dt@yenta.abq.nm.us (David B. Thomas) Subject: Re: How Do You Simulate Telco Battery Voltage? Organization: Yenta public access, Albuquerque, NM Date: Wed, 1 Jun 1994 00:53:26 GMT I have a schematic for a loop simulator that offers short and long line simulation as well as ring and backward polarity. It's pretty simple to build. I have the schematic only in paper form but I am willing to snailmail it to anyone who is interested. (I have built myself one of these and I use it all the time. You can even plug two phones in and have them talk to each other, or one phone and one answering machine, for offline testing.) David ------------------------------ From: dt@yenta.abq.nm.us (David B. Thomas) Subject: Re: DTMF Decoding Help Needed Organization: Yenta public access, Albuquerque, NM Date: Wed, 1 Jun 1994 00:55:32 GMT If you're an electronics hobbyist, you can get a DTMF receiver chip that never fails for under five bucks. Then you can interface it with a display and/or memory (to make your own standalone device) or with a serial line, for attaching to your computer or a terminal. I can get you part numbers, supply houses, even example circuits. Also try on sci.electronics. Nuts&Volts magazine has ads for kits and also ready-made DTMF readers. David ------------------------------ Subject: Re: RBOCS & Video Remote Learning in Schools? From: bob@bci.nbn.com (Bob Schwartz) Date: Tue, 31 May 94 18:08:59 PDT Organization: Bill Correctors, Inc., Marin County, California rv01@gte.com (Robert Virzi) writes: > In article , Gerry Moersdorf com> wrote: >> Does anyone have an opinion on what the RBOCS are trying to do by >> pushing TV remote learning grants and equipment to school systems? >> The schools in our district don't even have telephones in classrooms >> let alone a LAN for a client server teaching tool. To me the priorities >> are all turned around. What possible business could RBOCS build with the >> "poor" school districts? Consider that such "video lines" would allow teachers of special subjects to "travel" to schools telephonically. Advantage: One teacher could instruct more students in the course of a day. Disadvantage: The quality of instruction and the impact on jobs for teachers. This represents financial benefit to a school which must either bus the student to the teacher or get the teacher to be on campus. Stickey wicket with very broad ramifications 'eh? Education via television ... who else could benefit by turning teachers into TV proctors? Oh yes, let's not forget the absent mechanisms protecting children from commercial advertisment when they're a captive audience. Bob Schwartz bob@bci.nbn.com Bill Correctors, Inc. +1 415 488 9000 Marin County, California [TELECOM Digest Editor's Note: Wasn't that the complaint about a company called 'Channel One' which was going to give a bunch of video equipement free to any schools that wanted it? In return, all the schools had to do was tune in the broadcast Channel One presented every day to students with news reports, etc. Of course, there would be messages from the sponsor as well. But really, I can't get too worked up about that scenario. Life in the real world -- a place not frequented by very many Usenetters it seems -- :) calls for *money*, the root of all evil/good, to accomplish certain things. To me, its a trade off which if kept in the proper balance is a good one. For example, the schools in Chicago are in such terrible condition that anything -- anything at all -- would help. But they turned down Channel One's offer here; after all, there might be a commercial for some product and all the little children and their stupid teachers might somehow be unduly influenced. I suggest taking all those free offers being made to the schools, etc. After all, with the general condition of public education in the United States today, what possible harm could it do? Oh, I am sure the teacher's union would not like it, but phooey to them. PAT] ------------------------------ From: dt@yenta.yenta.abq.nm.us (David B. Thomas) Subject: Re: Cordless Phone Wanted With Ten Mile Range Organization: Yenta public access, Albuquerque, NM Date: Wed, 1 Jun 1994 01:07:40 GMT I used to belong to a ham radio club and we had a repeater up on a nearby mountain (sandia crest, for those who know new mexico). It has a phone patch on it and of course the range is in the hundreds of miles. Unfortunately, ham radio people in Albuquerque being what they are, anyone under 50 years of age is subtly discouraged from using it, with whatever lame excuses are handy at the time. Naturally, I quit paying the dues! But the technical part worked great, and I came really close to establishing my own club and repeater. I still own the phone patch and repeater hardware (wanna buy it??). I ended up setting up a simplex autopatch for my own use (which I'm also trying to get rid of). This is not as cool as a full duplex unit, as you cannot interrupt each other. It relies on timeouts and pauses during conversation. Actually I found that how well it works is a good indicator of the intelligence of the person on the other end. It definitely stopped me from dating some real bimbos. ;^) My grandma, a relative technophobe, handled it magnificently. Perhaps she comes from the old school where you wait till the other person stops speaking before you start. :-/ My setup wasn't strictly legal because the base station lacked an automatic station identifier. But those are cheap. (So was I.) I lived in a suburb of Albuquerque and beamed my signal into the city. It covered the whole city just fine, plus several miles outside in all directions. I had a nice high antenna on high terrain, though. So if you have a ham license or don't mind getting one, and are willing to spend some money up front on radios and the like, you can set yourself up pretty well. It's true that you're not allowed to conduct business transactions over the amateur radio service. This has never stopped me from ordering a pizza but it should be borne in mind! David occasionally admitting to call sign N5IZU ------------------------------ From: tawfig@cs.pitt.edu (Tawfig Al-Rabiah) Subject: Re: Cordless Phone Wanted With Ten Mile Range Date: 31 May 1994 18:24:01 GMT Organization: Univ. of Pittsburgh Computer Science Do you know who sells this type of phones? I need to get one to use overseas. Tawfig [TELECOM Digest Editor's Note: Yes, we understand, for export only. (Loud guffaws heard coming from audience). I suggest you buy one overseas in whatever country you plan to use it in. If it is legal in that country, I'm sure there are radio and telephone sales places that will gladly part with one in exchange for money. PAT] ------------------------------ From: nsayer@quack.kfu.com (Nick Sayer) Subject: Re: Book Review: "Internet: Mailing Lists" by Hardie/Neou Organization: The Duck Pond public unix: +1 408 249 9630, log in as 'guest'. Date: 31 May 1994 18:02:40 UTC Rob Slade writes: > "Most of the book is a listing of a number of mailing lists. NOOOOOOOOO!!!!!! It's bad enough that electronic sources for lists of mailing lists are so out of date. Now we have it all carved in stone so that generations of newbies yet to come will send mail to obsolete addresses that died eons ago. I don't suppose the authors asked before they put lists in their book. I don't suppose they _even_ _checked_ _up_ to see if the list was still alive. Will someone who has the book please look and see if 'catv@quack.kfu.com' or 'catv@quack.sac.ca.us' is in there and please put a contract out on the author(s) if so? > You can get similar lists on the net, but this includes lists from a > number of sources, as well as more detail than you might get from a > simple listing. They also have probably done some editing to get rid > of some deadwood. More than deadwood, actually. NETTRAIN doesn't > make it." > "So you could get all this free? Why buy the book?" > "Oh, you could get all the info, and more up to date stuff as well. That's the understatement of the year. I bet the rough draft was obsolete before it even got to the editor's. > But you'd have to grab yourself three or four huge files. Even then, > you wouldn't have all the info that is listed here. You'd also have > to check it out different ways, search all the synonyms for what you > want, and that sort of thing. If you are just a hobby user, maybe you > don't want this, but if you are serious about the Internet, then you > probably do. If you are acting as an Internet resource or trainer you > *definitely* want this book." NOT! They really want us to believe that a book is easier to search than a file? Barnum was right. Nick Sayer N6QQQ @ N0ARY.#NOCAL.CA.USA.NOAM +1 408 249 9630, log in as 'guest' PGP 2.2 key and geek code via finger ------------------------------ Date: Tue, 31 May 1994 16:26:32 -0500 From: Paul J Zawada Subject: Re: DS3 to Fiber Optic Convertor In article is written: > Does anyone know of a DS3 to fiber optic (multimode) converter? That > is a device that extends a T3 line over multimode optical fiber> Canoga-Perkins (818-718-6300) make T3-to-fiber converters in both multi- and single-mode varieties. Canoga-Perkins sells direct. Telco Systems makes a single-mode version but I don't know about multi-mode. (You can make single-mode optics work over multi-mode fiber over short distances.) Telco Systems equipment can be obtained through one of the big telecom distributors like Anixter. These things are pretty expensive. You can expect to pay about US$10,000 for a pair of multi-mode T3 extenders; US$15,000 for a pair of single-mode extenders. Paul J. Zawada KB9FMN NCSAnet Network Engineer zawada@ncsa.uiuc.edu National Center for Supercomputing Applications [TELECOM Digest Editor's Note: I though Anixter was more in the wire and cable business. Their headquarters is a block away from me over on Golf Road; in fact I applied for a job there once. PAT] ------------------------------ From: wtm@uhura.neoucom.EDU (Bill Mayhew) Subject: Re: Average Data Speed of Wire Telegraphy Wanted Organization: Northeastern Ohio Universities College of Medicine Date: Wed, 01 Jun 1994 02:48:29 GMT That would be a good question to refer to the rec.ham-radio. There were some pretty good articles on the subject posted there within the last year. From my faulty recollection, unassisted human send and receive speed records are in the 70 WPM range. That is five character words separated by a space. International Morse Code is a bit strange in that the symbol length is variable. Common letters such are encoded with short symbols. For instance, E is a single "dit". J is di-dah-dah-dah. ... and you thoght that the ideas behind LHZ compression were born in the 20th century? It isn't too difficult with a little practice to send and receive about 20 WPM without special equipment. That is about my level, and I don't particularly like brass-pounding on the radio. Several of my friends can hear 40 WPM, but use electronic keyers that have separate dit and dah paddles to make sending easier. I've never really gotten the hand of an electronic keyer ... it seems a little like defeating the purpose of sending Morse Code to use a keyer. Purists like to think of Morse Code transmission in religious terms. I don't really care too much, but code sending has the great advatage of being able to send a message around the world with just a few watts of power. A five watt Morse Code rig can probably send just as copyable, albeit slower, message as a 1500 watt single sideband voice rig in many situations. For Morse transmissions, the bandwidth necessary is approximately the WPM * 4. 60 WPM code only needs 240 Hz of bandwidth to prevent intersymbol interferece at the receiving end. On the shortwave bands, a voice signal might use as much as 2,300 Hz bandwidth and probably won't be able to do any better than 60 WPM spoken without error. For 8-bit radio telegraphy, ASCII for instance, the necessary bandwith is approximated by BW = ISHIFT * 1.2 * BAUD. To answer the prvious posting, yes, ASCII coded transmissions are now allowable. I forget when ASCII was adopted, but it's been in the ham radio hobby for 15 years or so. Before ASCII, the FCC permitted 5-level Baudot coded transmissions. A lot of Teletype brand and Kleinschmidt gear filtered out of the Bell system into ham radio in the 1960s. I still have a Teleype model 19 that first went into bell system service in 1932 sitting in my basement. The poroblem is that I can't find any easy way to get rid of it. Hams typically used 60 WPM transmission, but 72 was common in some nets. Some military machines were geared for 45.45 baud. I worked at Ft. Meade as late as 1980, and 45.45 baud maritime service was still common them. Such low speeds seemed ridiculous even then, but there was still a huge infrastructure of model 28 TTYs still around. 60 mA current loop operation was common for ham equipment. Government stuff operated at 60 uA with special magnets and contacts to minimize RF emissions for keyboards, perfs and trnamsmitter-distributor equipment. Ham radio has come a long way. 10.55 GHz links running tcp/ip at two Mb/s are in use. There are national infrasctructures running 9600 bps backbones AX.25 packet on VHF links scattered around the globe. Most local traffic is still relatively slow 1200 bps AX.25, but 9600 is gaining in popularity. HF links use multitone CLOVER systems now, with 300 baud the defacto standard, but 1200 baud and even higher tieing the continents together. Hams have even launched quite a few low earth orbit satelites with packet store and forward capabilities in an assortment of HF, VHF and UHF link and speed combinations. Bill Mayhew NEOUCOM Computer Services Department Rootstown, OH 44272-0095 USA phone: 216-325-2511 wtm@uhura.neoucom.edu amateur radio 146.58: N8WED ------------------------------ From: pheel@panix.com (Mike Pollock) Subject: Re: Misdialed Numbers Date: 31 May 1994 14:40:32 -0400 Organization: PANIX Public Access Internet and Unix, NYC About a year ago I got a call on my personal 800 number from a southern- accented guy. Apparently some friends of his at a truckstop had told him about the personal 800 numbers they use to keep in touch with loved-ones back home. He, it turned out, was simply trying to call his sister, who did NOT have an 800 number, by putting 800 in front of her seven-digit local number, which was the same as the last seven digits of my 800 number. I found all this out only after getting two confused-sounding hang-ups on my answering machine (I was screening). I answered the third call with "customer service?" at which point the gentleman explained his plight. I politely explained that, unless his sister subscribed to an 800 service, he couldn't just call her by adding 800 to her local number. ------------------------------ From: pheel@panix.com (Mike Pollock) Subject: Re: Sprint "Combined Billing" Error Date: 31 May 1994 14:45:49 -0400 Organization: PANIX Public Access Internet and Unix, NYC Robert M. Hamer (hamer@gandalf.rutgers.edu) wrote: > One solution is simply to not pay the NYNEX bill, call Sprint, and > tell them you don't want "combined billing." They didn't kick when I > did that. If they did kick, tell them you'll feel free to change to > another long distance company. You ought to be able to get rates > similar to Sprint's from lots of places. I subsequently did change back from combined to direct billing, but that was mostly because, as a combined subscriber, I could no longer get automated account information from the Sprint 800 number. Mike ------------------------------ From: animallib@aol.com (Animal Lib) Subject: Re: Annoyance Calls From Answering Machine Date: 31 May 1994 17:32:02 -0400 Organization: America Online, Inc. (1-800-827-6364) In article , quixote@eskimo.com writes: One other solution is to get the "CALL BLOCK" service from your local telco. This service, at least in Florida, allows you to enter a code to block the last number called. Since you don't have Caller ID you don't know the number anyway, but the call block service will permanently stop the machine from calling you. Also, Carlos, the SONY A3000 has call transfer. It lets you enter up to 32 digits so you can program it to call a beeper or whatever. Peace ... ------------------------------ From: gshapiro@rain.org (Gary D. Shapiro) Subject: Re: Annoyance Calls From Answering Machine Date: 01 Jun 1994 01:08:40 -0700 quixote@eskimo.com wrote: > Somehow I missed the first article of this thread. But I assume you > are talking about an answering machine that when it receives a > message, it will dial a preprogrammed number to alert about the > message just received. > I would be interested in such a machine, either the one mentioned in > this thread or similar ones in the market. Any help with brands or > where to buy them, will be greatly appreciated. Panasonic has more than one model that will forward messages. Mine, a KXT2634, is currently in a box in the closet. Its audio quality, both for the digital announcement and the microcassette messages is poor. Hopefully, this model is no longer available. Gary D. Shapiro Santa Barbara, California +1 805 682-5523 ------------------------------ End of TELECOM Digest V14 #262 ******************************