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Subject: RISKS DIGEST 9.84 REPLY-TO: risks@csl.sri.com

RISKS-LIST: RISKS-FORUM Digest Thursday 26 April 1990 Volume 9 : Issue 84

FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

Contents: [SPECIAL ISSUE. KISSIMEE MUCHO?] Re: You think YOU have problems with your telephone company? (Gary Chapman, David G. Novick, Vincent, Laura Halliday, Al Stangenberger, Pete McVay, John Higdon, Greeny)

The RISKS Forum is moderated. Contributions should be relevant, sound, in good taste, objective, coherent, concise, and nonrepetitious. Diversity is welcome. CONTRIBUTIONS to RISKS@CSL.SRI.COM, with relevant, substantive "Subject:" line (otherwise they may be ignored). REQUESTS to RISKS-Request@CSL.SRI.COM. TO FTP VOL i ISSUE j: ftp CRVAX.sri.com<CR>login anonymous<CR>AnyNonNullPW<CR> cd sys:[risks]<CR>get risks-i.j . Vol summaries now in risks-i.00 (j=0)

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Date: Wed, 25 Apr 90 11:37:36 PDT From: chapman@csli.Stanford.EDU (Gary Chapman) Subject: Re: You think YOU have problems with your telephone company?

The telephone system in Kissimmee sounds like the one in Moscow (the one in the Soviet Union, not in Idaho). Callers in Moscow are constantly getting wrong numbers, and those who have telephones are constantly interrupted by the telephone ringing, usually with someone who has reached the wrong number. I have heard people in Moscow say that the chance of getting the number that you dialed is 50-50, and this is something that everyone has learned to live with.

As I discovered in my hotel in Moscow, the people who do ring through to your telephone unintentionally are rarely surprised and never apologetic--in fact, they are frequently quite chatty. A strange form of social communication between strangers.

Here's a story from Moscow, which is apparently fairly representative:

A man lives in an apartment building with only one telephone serving about a hundred residents. One day there is a fire in the building. The man rushes to the telephone to call the fire department. He picks up the telephone and is inexplicably connected to his workplace, and his boss is on the line. The man is momentarily flustered, the boss says, "How nice to hear from you." The man is a little stressed, trying to figure out how to get through to the fire department before the fire gets out of control.

Man: "I'm sorry. . . " Boss: "You sound upset. What's wrong?" Man: "We have a situation here." Boss: "What do you want me to do?" Man: "Nothing." Boss: "Then why did you call me?"

I'm sure there are many more amusing (and not so amusing) effects of having a telephone system that is so unpredictable. The Soviet telephone system is non-digital, of course, and still uses old cross-bar switching. This is unlikely to be the problem in Kissimmee, but the problems sound similar.

Gary Chapman, Executive Director, CPSR

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Date: Wed, 25 Apr 90 15:42:33 -0700 From: "David G. Novick" <novick@cse.ogi.edu> Subject: Re: You think YOU have problems with your telephone company?

I had first-hand experience with a single instance of a very similar problem. This occurred in the U S WEST Communications phone system for Eugene, Oregon, around 1988.

A friend of mine called me from his home. A little later I returned the call. Instead of any normal response, the phone system responded with the out-of-service message: three loud tones followed by "The number you have called has been disconnected or is out of service..." On a couple of subsequent tries (motivated by suspicion that I made an error, followed by disbelief), I always got the same message. Eventually I called an operator to complain.

It turns out that my friend's phone had been forwarded to another number, despite the facts that (1) the other number was not a working number and (2) my friend did not have call forwarding. It seems to have been an internally generated system error. A disturbing aspect of this is that my friend could always call out, so that his phone seemed to be working; it's just that no-one ever seemed to call them. It is unknown how long this state had existed. Indeed, if the number to which the calls were being forwarded was a working number that turned out to be either always busy or not answered, this situation might have continued indefinitely.

David Novick

Department of Computer Science and Engineering, Oregon Graduate Institute of Science and Technology, 19600 N.W. Von Neumann Drive, Beaverton, OR 97006-1999 (503) 690-1156

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Date: Wed, 25 Apr 1990 18:23:52 -0400 From: vincent@neat.cs.toronto.edu Subject: Re: You think YOU have problems with your telephone company?

Several years ago (1984) I worked as a summer student in Bell Northern Research (which is the research arm of Northern Telecom and has nothing to do with Bell in the states). At the time they decided to field test one of their new SL100 switches (hope I have the right number) by making the people who made it live with it.

Anyway, for the first month or so after the introduction of the system we experienced problems very similar to the ones mentioned. I personally experienced the "match-making" phenomena of having the phone ring, hearing it ring on the other end and then having someone else answer. Very weird.

Phone calls would not only fail, but were misdirected and at times switched. Most of these glitches ended quite quickly but it took a month or two for everything to settle down. This was the first phone system that I had dealt with that had all those nice features which phone companies are starting to offer: call forwarding, call park, speed dial directories stored off the handset etc. I'm sure that interactions between these features contributed to the problems. Perhaps someone at BNR remembers this episode and actually knows something about why it happened. It may be worth trying to contact them, especially if it is one of their switches.

Vincent

P.S. This occurred in the first few months of 1984 and it did send a good Orwellian shiver up my spine.

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Date: Wed, 25 Apr 90 14:29:28 -0700 From: amos@nsc.UUCP (Amos Shapir) Subject: Re: You think YOU have problems with your telephone company?

In Israel the (government owned) company is notorious for such incidents. Where I live, connections to numbers in Tel Aviv starting with 4, especially 41 and 42, are sometimes close to impossible, with all the phenomena you mentioned, especially cross-talk between lines. The common explanation is that this is an old exchange which is overloaded. In any case, all this is caused by bad hardware, mainly due to rain damage (when it rains, they have to wait until the lines are dry before fixing anything; but then they don't know where the cracks are!).

There are new and computerized exchanges too, but the only difference seems to be that there such malfunctions are echoed into billing too, and of course, they blame the computer for *everything*. Amos Shapir

National Semiconductor, 2900 semiconductor Dr., Santa Clara, CA 95052-8090 Mailstop E-280 amos@nsc.nsc.com until May 1, then back to amos@taux01.nsc.com

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Date: Wed, 25 Apr 90 20:10:45 PDT From: laura halliday <halliday@vaou02.enet.dec.com> Subject: re: You think YOU have problems with your telephone company?

The note in Risks 9.83 about the Florida woman and her telephone `service' sounded, remarkably like a failure I saw in a C-1 electronic exchange some years ago.

Background: the C-1 was a very early electronic exchange. It was a hybrid, with electromechanical line equipment and a digital computer for brains. The line equipment came in large cabinets, with cables to route calls from one cabinet to another and more cables for status information back to the processor.

The system went crazy one afternoon. You could pick up the phone and you would get dial tone perhaps 10% of the time. The rest of the time you'd get a mixture of other peoples' conversations, and busy and reorder signals. The phone would ring randomly, and you would get the same mixture of garbage if you answered it.

The problem turned out to be hardware. *One* wire had broken - one of those signal wires, and, since the line equipment cabinets were daisy-chained, and the broken wire was close to the processor, the whole thing went down. It was buried deep inside a cable run, and took a couple of days to find.

...laura halliday, DEC Canada, halliday@vaou02.enet.dec.com

Opinions: MINE! Nothing to do with DEC Canada.

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Date: Wed, 25 Apr 90 18:27:26 PDT From: forags@nature.Berkeley.EDU Subject: re: You think YOU have problems with your telephone company?

Often when telephone installations are changed, not all wires which were connected to the original installation are disconnected. These residual connections can be in a central office, on a pole, or in a building. When a new phone installation re-uses these apparently "dead" wires, trouble can arise.

1. A friend found a modular telephone jack in the basement of a house which he just bought. The jack had dial tone, so he used it as an extension phone. A couple of months later, his neighbor remarked that he had been getting billed for long-distance calls which he had never made. My friend recognized the areas called as calls which he had made. Explanation: the former occupant of my friend's house had had two telephone numbers; the wire feeding the jack in the basement was connected outside on the telephone pole to the same pair as the neighbor's telephone.

2. My parents had their telephone number changed. They still got calls from people dialing their old number. The service rep at the phone company said that was impossible -- the next call my parents got was from the service rep dialing their old number (she was very embarassed, naturally). Apparently a jumper in the central office had not been disconnected so their phone rang through two separate numbers.

3. Many phones in my building at U.C. used to use 4-wire circuits. When we upgraded to 2-wire circuits (with the central office switch replacing a rack of relays in our basement), many of the extra wires were not disconnected from the telephones. I've traced three problems with new phone and data line installations to using pairs which were also connected somewhere else to a telephone although the wires were not used for dial tone.

Al Stangenberger, Dept. of Forestry & Resource Mgt., 145 Mulford Hall - Univ. of Calif., Berkeley, CA 94720 BITNET: FORAGS AT UCBVIOLE (415) 642-4424

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Date: 26 Apr 90 10:24 From: pmcvay%contra.DEC@src.dec.com (Pete McVay, TAY2-2/F14, 227-3598) Subject: re: You think YOU have problems with your telephone company?

I worked with a network security organization a few years ago. While my job did not directly involve phone phreak investigations (those individuals who attempt to hack "telecommunications" rather than "computers"), I did overhear some information that seems to fit in with the Kissimmee woman's phone problems--that is:

o some hackers were known to have infiltrated major telephone networks and set up their own trapdoors and Trojan Horses in the switching software. The statement was made that "many telecommunications vendors are not in control of their own systems".

o there was evidence that at least one phone phreak could do anything in a major phone system that the owners could--that is, grant services (call forwarding, etc.), disconnect or enable phone service, and change billing. This included the ability to make "invisible" (non-charged and unrecorded) long-distance phone calls.

o some of this ability was used for harassment: law-enforcement officials and/or people the phone phreak personnally did not like receive huge phone bills. Friends of phone phreaks found their bills greatly reduced.

The one item that does not fit, however, is the visibility of this woman's problems. Typically the phone phreaks kept their activities quiet: advertising them would spark an investigation and possible breakup of their access. Such harassment that did go on was minor and was not on a continuing scale such as this woman described. But maybe she antagonized a phone phreak in a major way: could she be a prominent community activist on social or environment issues, for example?

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Date: 26 Apr 90 00:06:41 PDT (Thu) From: john@bovine.ati.com (John Higdon) Subject: re: You think YOU have problems with your telephone company?

Missing details in the mysterious case of the Florida woman experiencing much trouble with her telephone service make intelligent comment impossible. Probably most the most important consideration would be the type of central office switch involved. Since we are not dealing with an RBOC, it could be anything; some of those off-the-wall switches are capable of some rather bizzare behavior. Also, it is significant if this is rural service.

The "crossed line" problems sound like difficulties associated with "pair gain" equipment. To make an outdated, undersized outside plant serviceable, telcos sometimes resort to concentrators. These are devices that allow many subscribers to have what appear to be private lines over a somewhat smaller number of actual circuits. This is not to be confused with digital "remote" offices, which actually provide the functional equivalent of private lines (within their blocking factor limitations) over digital carrier back to the host central office. Concentrators are fraught with difficulty, most of it similar to the "crossed wire" effect observed by our subject.

All in all, it sounds as if our hapless woman is plagued with problems resulting from multiple causes: difficulty with the 800 carrier, possible CO trouble, possible outside plant trouble, etc. In my library of telephone experience, I have never had anything to compare with our Florida victim, but my universal solution might be something to consider.

On several occasions, I have had difficulty of one sort or another that the telco simply has not been able to correct. Either it has been of an intermittant nature and not detectable by test personel or the solution has just simply eluded the maintenance staff. When it appears that the difficulty cannot be corrected in a timely manner, I order a new service. After the new service is completely installed, the old (and troublesome) service is disconnected. This ensures that no part of the old service remains; not the cable pair, CO line equipment, nor any line conditioners or loop extenders. This tactic has not failed to correct seemingly "insoluble" problems.

Another consideration: if this woman is the victim of someone's maliciousness (a real possiblity) then the solution might be elusive. This "someone" obviously has software (and most likely hardware) access to the telco and could be very hard to track down. A second, more likely but almost as difficult to deal with, possiblity is that the telco is just plain messed up. In that case my "universal solution" might correct her current problems and bring on others.

In any event, I would be very interested in getting further details. If her area code/prefix could be revealed, I can determine what type of CO switch is involved. Also, I can probably research what type of outside plant we are dealing with. Solutions are not guaranteed, but the finger pointing might become a little more educated.

John Higdon, P. O. Box 7648, San Jose, CA 95150 +1 408 723 1395

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Date: Thu, 26 Apr 90 02:31 CST From: GREENY <MISS026@ECNCDC.BITNET> Subject: re: You think YOU have problems with your telephone company?

Well, this may not be related to a phone company problem, but when I was an undergrad, the university decided to go from party line rotary phones, to a brand-spanking-new digital switch and give everyone their own private line.

No problem right? Well you know the answer to this one. Not only did we get our own phone lines, but all the neato features that come with a digital switch such as call forwarding, speed dial, three way call, call waiting, etc...And the ability to have a "secret" 5 digit code to bill your calls to.

Due to a "programming error" it was quickly discovered that you could use your "secret" code from any telephone on campus. And of course if you happened to incorrectly enter your "secret" code at another phone, chances were that it was someone elses "secret" code that you entered, and the call would go through! Of course when that person's bill came, it showed up as a call from a phone they werent at for a number they didnt call. So of course the local telephone people on campus got this bug fixed -- after about a month and an unknown # of "misentered" secret codes...

After this fix, another neat thing would show up. During the late hours of the night (when all the CS hackers do their things and make avid use of all the modem lines on campus), the digital switch would tend to "hang", and would not produce a dial tone. Sometimes it would actually connect you as an additional party to a conversation in progress and although you could hear both sides of the conversation -- they couldnt hear you no matter what tone you sent or how loud you screamed. After the two parties hung up, if you stayed on the line, you would be connected to the next phone call which either of those two parties made -- although they could hear you this time. However they could not dial, and until you hung up they couldnt dial. Through some trial and error, a friend of mine and I discovered that by hitting *99 (which would kill all of your personal speed dial #'s), that the entire switch would reset -- loosing all the speed dial #'s, and other pre-programmed goodies...

Needless to say, after reporting this occurance the university did nothing, so we talked to the makers of the switch -- GTE, and they came out and fixed it... No problems since then.

Moral of the story: Software controls our lives, and is written by people who are subject to sleeplessness, caffeine (or other drug addictions), or just plain forgetfullness (how many times have you left out a { in some C code?). We had all better be aware of the risks, and do the best we can...

Greeny BITNET: MISS026@ECNCDC

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End of RISKS-FORUM Digest 9.84 ************************