Author Topic: a rogue 911 call from a KTS....  (Read 1137 times)

Offline poplar1

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Re: a rogue 911 call from a KTS....
« Reply #15 on: April 24, 2017, 12:49:35 AM »
Yep,  I work at a bank, and the local 911 folks are kind of touchy when a 911 call comes in from a bank.  I learned the hard way that any sequence that starts with 911 results in a 911 call.  In our PBX, like most others, you dial a 9 for outside then dial a 1 for a "long distance" call, whatever that is these days.  Anyway, I went to call someone and hit the 9, then a 1, then accidentally hit the wrong next number.  I hit another 1.  It didn't even register with me that I had just dialed 911.  I just hung up to try again.  Right after I hung up from that call my phone rang and it was the police asking why I had called 911.  I had to think about it, but after a short explanation, I found out from them that what I did was more commonly done than one would think.



Perhaps you could ask the bank to change the trunk access code to something other than "9", at least for long distance calls. State of Georgia Centrex and PBXs used 9+ for outside non-toll calls and 8+ for toll calls.
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Offline twocvbloke

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Re: a rogue 911 call from a KTS....
« Reply #16 on: April 24, 2017, 01:41:04 AM »
What happens if you dial "999" from a PBX line that requires dialing 9 for outside? This would be the same as dialing "99" from a residential line, would it not?

Yes, dialling 999 from behind a PBX such as a 308 results in the outside line only receiving "99", but most phones back then would have been marked as "Emergency, Dial 9-999", I'm sure more modern systems will recognise the string as an emergency number and pass it through...

On an interesting note, the 2500-style phone I got recently that came from a Best Western in Phoenix actually says on the instruction card "Emergency 911", with no mention of dialling a leading 9 for an outside line like the rest of the instructions, so, I presume their system passed the 911 through without having to dial 9911...

Offline jsowers

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Re: a rogue 911 call from a KTS....
« Reply #17 on: April 24, 2017, 10:54:08 AM »
Yep,  I work at a bank, and the local 911 folks are kind of touchy when a 911 call comes in from a bank.  I learned the hard way that any sequence that starts with 911 results in a 911 call.  In our PBX, like most others, you dial a 9 for outside then dial a 1 for a "long distance" call, whatever that is these days.  Anyway, I went to call someone and hit the 9, then a 1, then accidentally hit the wrong next number.  I hit another 1.  It didn't even register with me that I had just dialed 911.  I just hung up to try again.  Right after I hung up from that call my phone rang and it was the police asking why I had called 911.  I had to think about it, but after a short explanation, I found out from them that what I did was more commonly done than one would think.

I can echo what Bill is saying because I used to work for a school system and they also don't ever ignore when a school dials 911. In NC we also have area code 919 and that has always presented problems when people dial "9, 1, 919" and misdial with an extra 1 and hang up. More than once we had calls about someone inadvertently dialing 911 because our Cisco IP phone system used 9 for an outside line and went to every teacher's classroom, so even students could be the ones who misdialed. We're just lucky the 919 area code is about 100 miles away from us, from Raleigh-Durham to Ft. Bragg.
Jonathan

unbeldi

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Re: a rogue 911 call from a KTS....
« Reply #18 on: April 24, 2017, 11:28:12 AM »
9 is inserted, not absorbed, whenever someone dials "9,11." This allows the call to be completed as if "9,911" had been dialed.

When an AT&T customer orders a new Centrex here, the usual offering includes "assume dial 9." This allows the subscriber to dial outside calls as 10 digits (NPA-NXX-XXXX) rather than dialing 9 (to access a NAR) + 10 digits. Calls to other lines in the same Centrex group are usually 4 or 5 digits.

Perhaps some people are programming their systems to always insert a leading 9, so that no trunk access code has to be dialed.
South Fulton Hospital here has changed the trunk access code on their PBX  from "9" to "8."

No digit insertion is needed because the outgoing trunk can be immediately selected when dialing 911.
This only applies to dialing 911. In all other situations it is absorbed for trunk selection.  A leading 911 dialed by a user must always be specially recognized immediately, that is why I suggested that this is a people problem.   "1" is never the leading digit of an area code, CO prefix, or international access code, so dialing 911 can immediately be recognized as an emergency call.

I think the problem the law tried to address is that some people designed dial plans poorly to require dialing 9-911.
« Last Edit: April 24, 2017, 11:36:09 AM by unbeldi »

Offline Dan/Panther

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Re: a rogue 911 call from a KTS....
« Reply #19 on: April 24, 2017, 11:45:09 AM »
All cell phones have a built in automatic 911 feature that you can't disable. All I have to do is push on the touch screen, and magically 911 is dialed.  I butt dialed 911 at while driving once.
Maybe the circuit in your KTS is mimicking that circuit.

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unbeldi

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Re: a rogue 911 call from a KTS....
« Reply #20 on: April 24, 2017, 11:46:24 AM »
Of course nothing can guard against human dialing errors.   This is why a dialing plan must be carefully designed, and practices like 9-911 are simply inexcusable, IMHO.

With modern IP telephony, the use of 9 for trunk selection can usually be avoided.

Offline poplar1

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Re: a rogue 911 call from a KTS....
« Reply #21 on: April 24, 2017, 03:17:35 PM »
No digit insertion is needed because the outgoing trunk can be immediately selected when dialing 911.
This only applies to dialing 911. In all other situations it is absorbed for trunk selection.  A leading 911 dialed by a user must always be specially recognized immediately, that is why I suggested that this is a people problem.   "1" is never the leading digit of an area code, CO prefix, or international access code, so dialing 911 can immediately be recognized as an emergency call.

I think the problem the law tried to address is that some people designed dial plans poorly to require dialing 9-911.

I think you and I are using these terms -- digit absorption and digit insertion -- in different ways.
Digit absorption, as on a 1st or 2nd selector of Step-by-Step CO equipment, means that the equipment effectively ignores one or more digits dialed by the subscriber. The Fairburn, GA CDO, for example, was assigned the NNX 964. You could dial 964-2xxx or 4-2xxx. The 9 and 6 were absorbed by the 1st selector. The phone directory said to dial all 7 digits, but everyone in the area knew that you could dial only the last 5 to reach another 964- number.  (For calls to Atlanta, you dialed 8 + the 7-digit number.)

Depending on the way the equipment was optioned, these digits can be absorbed repeatedly (dial them as many times as you want), absorbed once but only once, or required (call will not be completed if all 7 digits are not dialed).

Digit insertion means that the equipment adds additional digits to the number string dialed by the subscriber. Until about a year ago, on a Verizon cell phone, I could dial 7 digits to call another land line or cell phone in the same area code 404. Or, I could dial the entire 10-digit number. If I dialed only 7, then Verizon inserted the 3 leading digits 404.

On software-controlled PBXs and Key Systems with ARS (Automatic Route Selection), the system looks at the complete number dialed by the subscriber and picks the most economical route available at the time. It might for example pick a Band 1 outgoing WATS trunk for a call to a nearby state, but if that trunk group was busy, then it might pick a Band 2 group, or even go out over the most expensive route, if the class of service of that station permitted that.

The problem addressed by Kari's Law is that some people -- particularly a child witnessing a violent crime -- may not know or think to dial an access code. So, the law requires the PBX to insert the trunk access code (9) Whenever someone dials 911, the system reacts as if 9911 was dialed. No doubt, it also allows 9911 to be dialed by the user.

What the law does not address is the unintended consequence that people dialing 9 for trunk access then 1 to indicate a 10-digit number to follow may inadvertently dial an extra 1, or fumble the switch hook, thus reaching the 911 Dispatch Center. The law does allow the following exceptions to the requirement to insert the trunk code when a person dials  "9-1-1" :
(1) where hardware or software had not been upgraded
(2) where the call can instead be diverted to a local responding center on the premises.

Kari's law addresses the fact that legacy PBXs, through design, required a trunk access code, usually 9, for all outside calls, including calls to the 911 dispatch center. And a 9-year old child trying to reach 911 did not know that she needed to dial 9 then 911.  This was not the "poor design" by IT techs trying to be telephone techs, but just the way PBXs were designed. If there is any poor design, it was the choice of 911 as the service code, since 9 was already assigned on most systems as a trunk access code. But it was chosen by AT&T and the FCC because it had never been assigned as an NPA (area code), central office code, or service code (such as 211 for Long Distance Operator, 411 for Directory Assistance, 4107 for Test Board, 611 for Repair, etc. )

Many systems do allow conflicts in the dialing plan, because they "time out" if no more digits are dialed. So a 5ESS recognizes either *72, 1172, or 72 (with a 5 second pause after 72, if no additional digits are dialed) to set up call forwarding, even if 72 can also be the first 2 digits of a NNX (7-digit number) or NPA (local 10-digit number).  So, perhaps a system could be programmed NOT to call the 911 Center if someone intending to dial 9, 1-213-555-1212 dialed instead 9, 11-213-555-1212. However, this would probably not be allowed because someone intending to reach 911 might without thinking dial extra digits.

Since 911 is standard, and insertion of  trunk access code by the PBX is mandatory when someone dials 911 without dialing the access code, the simplest thing to do now is to choose a different code to dial  for accessing an outside line for all calls other than 911, while still allowing "911" or "9911" to be routed to the 911 dispatch center. Or, leave "9" for calls to local 7 or 10-digit numbers, and assign another number (8, for example) rather than "91" for toll calls.

Of course, some places now require 1 + 10 Digits for all calls outside the local area code, and still allow 7 digits for those calls to the same area code. But then when an area code gets an overlay, 7-digit dialing is no longer permitted. This means all calls will now be 11 digits. So, for calls from PBXs, if the trunk access code is 9, then it seems misdialed calls may be a recurring problem (because every call other than to another PBX extension will begin with 91).

« Last Edit: April 24, 2017, 03:23:23 PM by poplar1 »
"C'est pas une restauration, c'est une rénovation."--François Martin.

Victor Laszlo

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Re: a rogue 911 call from a KTS....
« Reply #22 on: April 24, 2017, 06:50:01 PM »
(Sigh) another case of idiots in power trying to overcome a simple problem by making it so complicated that we all just throw up our hands.

It would not cost THAT much to equip any hotel room phone with a button marked "911" similar in size and placement as the useless "TAP" buttons of the past.

For probably a buck or two per $15 phone, all the caller would need to do is press the button. The circuit board in the phone would do the thinking, and translation, necessary to get the call to the PSAP.

Offline Babybearjs

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Re: a rogue 911 call from a KTS....
« Reply #23 on: April 24, 2017, 10:43:30 PM »
Dan- Butt Dialing.... that's it... my KTS was Butt Dialing 911!
John

Offline mentalstampede

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Re: a rogue 911 call from a KTS....
« Reply #24 on: April 25, 2017, 08:53:34 AM »
This thread made me think of this:

https://youtu.be/FBQyksGkGKA
My name is Kenn, and I like telephones.

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Offline Babybearjs

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Re: a rogue 911 call from a KTS....
« Reply #25 on: April 25, 2017, 02:18:26 PM »
Cute Video....
John

Offline Owain

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Re: a rogue 911 call from a KTS....
« Reply #26 on: April 25, 2017, 04:04:21 PM »
It would not cost THAT much to equip any hotel room phone with a button marked "911"

But would a child know to use that button if they didn't have one at home?

And with very young children around a single button for 911 on the phone increases the risk of unintentional calling.

The real awkwardness I think is the use of 9-1 for 'access + long distance' as well as 9-1 (then 1 for emergency), and you have 91x as area codes as well.

In the UK with PBX digit insertion we could set 9-99 to dial 9-999 immediately as there is no other number or code starting 99. Historically many exchanges would connect to 999 after dialling 99, because sub-exchanges would dial 9 to access the parent exchange, and the 99 level on the parent exchange would go to emergency.