Comment by codewritinfool | Hacker News Reader

Comment by codewritinfool | Hacker News Reader

Oh man, this reminds me of a time that I got into trouble. We had a phone system (Isotech 228, IIRC) that had these boxes call OPXIs that let standard telephone equipment connect to the phone system. They provided talk battery and ring voltage.

We had a modem tied to an OPXI, which required that our dial strings in Telit (remember that? I liked it better than Procomm) start with "91,", which was 9 for an outside trunk, then 1 to select a trunk, then a comma for a pause. Then the phone number of the BBS site.

The OPXI messed with the newer modem speeds. One Friday I decided that we didn't really need the OPXI if I bridged the modem with the fax line, so I did.

I didn't tell anyone. That was a mistake.

Monday morning I showed up for work and my boss (the chief engineer and president) called me into his office. Uh oh.

He said, "Did you remove the OPXI from the modem line in the lab?" "Yes." "Why?" "Because we didn't need it."

He then told me about how he came in on Saturday, finished up some PCB artwork and went to dial into the board fabricator's BBS to upload the files (long distance), and kept getting failures to connect. He tried it a bunch of times before he heard banging on the front door. He went to the front and there were multiple police officers outside. They said there were multiple 911 hangups from this location and wanted to know why. He swore that he was the only one there and there were no 911 calls. They then wanted to come in and look around the building, so he let them.

After they left, he put it all together. The dial strings were set up to dial 91,1-areacode-phonenumber which dialed 911 emergency without the OPXI in the path.

He verified that the OPXI was no longer in the loop and was ticked off. He knew immediately who did it.

He said, "Things you do to systems other people use can have unintended consequences. Please think those things completely through in the future."

Good advice, and I still hear his voice in my head today when I'm reconfiguring something.

That reminds me of my younger days in Champaign-Urbana, which had a hopping BBS scene in the 1980s. I had a FidoNet node and I was going to make a file request from a BBS in Québec. I queued the file request, went to sleep... and was awakened by the sound of cops bashing on my apartment door at about 2 AM.

At the time, E911 wasn't a thing, and the local PD had the number 333-8911. Guess what the local number was for the BBS? I had FUBARed my nodelist processor configuration, and it was stripping off the 1-819- [I think it was 819]. Oooops.

Needless to say, the node didn't get restarted until I fixed the problem.

Once as a kid, staying at a hotel, I tried to call some family staying in Room 117. For whatever reason, the call didn't go through. I glanced again at the instructions on the phone, which said "please dial a 9, then your number". So I did. The police showed up fifteen minutes later.

And while "9" is a bad special prefix, the "91" in your story has to be the worst possible in the US.

> And while "9" is a bad special prefix, the "91" in your story has to be the worst possible in the US.

Possibly the only worse prefix would just be straight-up "911." 91- is just unimaginably dumb.

Our building once leased out a portion to a call center based in India. India's country code is "91" and to get out on the PBX was "9". But this old junky Nortel system would outpluse immediately when it saw the dial string "911". So when ever someone would try to dial "9911XXXXXXXX" it would immediately outpulse to our local PD when the dialed digits equaled 911. And whenever the outbound caller heard the PD pickup, they would get scared and just hangup.

Ugh. Those were good times.

Yep, I misdialed a friend's number once and hung up before completing the seven digits, then mistakenly let my parents answer the phone when we got the call back a few seconds later. Needless to say my parents were pissed and chose to believe that I was pranking rather than accept that I was simply an idiot.

"One Friday" has never been the start of a good work story ;)

Wait, you mean that in `git push -f`, the `-f` is not the Friday flag?

Of course not. "Friday" isn't universal. Clearly, `-f` is the "Finally" flag

> He said, "Things you do to systems other people use can have unintended consequences. Please think those things completely through in the future."

Sounds like you had a good boss. I expected the story to end with you getting fired. My current boss is like yours, which is why I joined the team.

Worked at a small regional telco in the 90's. Many of our customers were in the 810 area code and one day a minor change was made in the call records they read into the billing system. It started interpreting 81 as a country code and tried to bill people for calling Japan. Fortunately IIRC this was caught before the bills went out.

And this is why 9 is a terrible default for PBX systems. Hell, it probably was the default before 911 came into wide use.

I think that's the most important lesson that people should learn. If a huge number of calls all start with "91" then something has already gone terribly wrong.

Where I grew up in LA, one of the local exchanges started with 991. I had a lot of friends with 991 numbers, and in fact, our second line, for our modem, was also a 991 number.

There were a lot of misdialed 911 calls in our area.

Ouch. So this would have worked correctly if you had also removed the '91,' from the dial string within Telit?

Yes.

I think you meant 'Telix', not 'Telit'.

Yes! Thank you. I've worked with Telit devices recently (which also have an AT command set) and my brain got it wrong.

I have this substitution issue with some regularity, very frustrating. Last Friday I sent out an 'all hands' for our company with info on the job for the week of the 10th of September... even did it wrong twice in one mail.

this kind of thing is why pbx callout prefix is normally 7 these days, instead of 9.

Maybe he should have been mad at whatever asshole decided to put the first 2 of 3 digits of 911 in the dialout code, jeez.

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