Who picked the sequence of 9-1-1?

[Phil Thien]

I do IT, and these days a lot revolves around business phone systems.

Most of these systems use "9" to get an outside line, and of course "1" to dial a long-distance number. Right there you're only one digit away from dialing emergency services.

So yes, Thursday for the 2nd time in a year I dialed 911 at a client site.

Brand new phone, the "1" button bounced and gave me two, and the next thing I know I was talking to the 911 operator.

On our work system we don't dial 9 to get an outside line, because I despise this. But on many systems where they have a ton of employees that have dialed 9 for years, they don't want me rocking the boat by changing their dialing plans.

Couldn't they have made it some other sequence though? Who the heck came up with 911?

[paul cottingham]

Usually, when I set up dial plans, I would make the emergency number 9911, for this very reason. It was never a problem as people would dial 9 automatically anyways.

[Dave Lehnert]

I always heard that they picked the date the system was invented. Sept. 11th.

[Eric DeSilva]

Here's one possibility: http://www.911dispatch.com/911/history/background.html

Although you may be putting the cart before the horse--you could just as easily ask who decided that it was appropriate to use "9" to access an outside line on a PBX. I'm guessing that most systems at the time of 911's birth were key systems, not PBXes, so I'm going to guess that 911 pre-dated the use of "9" for an outside line...

I'm also a little mystified how it is that I never have to dial "1" on my cell phone to call long distance, but my office PBX hasn't managed to figure out that problem. That would sort of solve the problem too.

[Robert LaPlaca]

I do IT, and these days a lot revolves around business phone systems.

Most of these systems use "9" to get an outside line, and of course "1" to dial a long-distance number. Right there you're only one digit away from dialing emergency services.

So yes, Thursday for the 2nd time in a year I dialed 911 at a client site.

Brand new phone, the "1" button bounced and gave me two, and the next thing I know I was talking to the 911 operator.

On our work system we don't dial 9 to get an outside line, because I despise this. But on many systems where they have a ton of employees that have dialed 9 for years, they don't want me rocking the boat by changing their dialing plans.

Couldn't they have made it some other sequence though? Who the heck came up with 911?


Kind of funny story, I worked in the IT world also and most every PBX used the famous 9 for outside lines.. Was at my elderly mothers house in another state, went to dial someone from my mothers landline phone and started to realize I had erroneously dialed 9-1, hung up figuring not harm was done. About 10 minutes later the local police showed up at the front door, needless to say I was in total amazement... The officer was nice enough, just wanted to make sure all was OK, I told him that I only dialed two digits and he said after digits 9 + 1 the call goes though as a 911 call! I told him they must get millions of erroneous 911 calls, he said you better believe it.

Still kind of find it hard to believe that the Verizon phone switches state engine doesn't wait for the third digit, but I didn't want to attempt to test it out again to see..

[paul cottingham]

Here's one possibility: http://www.911dispatch.com/911/history/background.html

Although you may be putting the cart before the horse--you could just as easily ask who decided that it was appropriate to use "9" to access an outside line on a PBX. I'm guessing that most systems at the time of 911's birth were key systems, not PBXes, so I'm going to guess that 911 pre-dated the use of "9" for an outside line...

I'm also a little mystified how it is that I never have to dial "1" on my cell phone to call long distance, but my office PBX hasn't managed to figure out that problem. That would sort of solve the problem too.
That is a matter of the dial plan. If your office has any extensions that start with "1" then putting it in the dial plan would cause chaos. (I think. It has been a while since I set up an Asterisk system.)

[Eric DeSilva]

I think what I was saying is that the choice of "9" to access a line for a PBX could just have easily have been "8", for example. I'm assuming they used "9" because it allows you to assign PBX extensions from 1000 through 8999 continuously, rather than 1000 through 7999 then from 9000 to 9999 (I'm actually guessing they don't assign the range 0001-0999, but they may not assign 1000 through 1999 either). But I don't think most people really would care.

The issue with "1" for long distance is a different one. I can dial NPA-NXX-XXXX or NXX-XXXX from my cell phone and it connects correctly. Dialing NPA-NXX-XXXX from my office PBX system doesn't work unless the number is in the local calling area--otherwise I have to dial 1-NPA-NXX-XXXX. The point is that my $500 smartphone can figure this out but my $10M PBX can't, which strikes me as odd. It may be that in landline systems you still pay separately for LD services so there has be some differentiator for LD, whereas LD is bundled into most (if not all) cell phone plans. I still find it annoying, since as an end user, it doesn't matter to me whether the number is LD or local--if I need to make the call, I need to make the call and I'm not paying for it anyway.

[Phil Thien]

Usually, when I set up dial plans, I would make the emergency number 9911, for this very reason. It was never a problem as people would dial 9 automatically anyways.

Normally we do, but we have clients that insist on both 911 and 9911 working. And this was one of those.

[Brian Elfert]

We went from an old expensive PBX at work to a software based PBX that uses SIP based VOIP phones. The old PBX required a 9 for an outside line, but it allowed both 911 and 9911 for a 911 call. The new system doesn't require 9 for an outside line. It still requires a 1 for long distance, but I think that could be changed through programming. Like someone else said, I think office systems still require a 1 for long distance because long distance isn't free. I know at my office no one gives a second thought about a long distance call because we pay like 2 or 3 cents a minute these days.

[Phil Thien]

I think what I was saying is that the choice of "9" to access a line for a PBX could just have easily have been "8", for example. I'm assuming they used "9" because it allows you to assign PBX extensions from 1000 through 8999 continuously, rather than 1000 through 7999 then from 9000 to 9999 (I'm actually guessing they don't assign the range 0001-0999, but they may not assign 1000 through 1999 either). But I don't think most people really would care.

The issue with "1" for long distance is a different one. I can dial NPA-NXX-XXXX or NXX-XXXX from my cell phone and it connects correctly. Dialing NPA-NXX-XXXX from my office PBX system doesn't work unless the number is in the local calling area--otherwise I have to dial 1-NPA-NXX-XXXX. The point is that my $500 smartphone can figure this out but my $10M PBX can't, which strikes me as odd. It may be that in landline systems you still pay separately for LD services so there has be some differentiator for LD, whereas LD is bundled into most (if not all) cell phone plans. I still find it annoying, since as an end user, it doesn't matter to me whether the number is LD or local--if I need to make the call, I need to make the call and I'm not paying for it anyway.

Right, 9 would have been used originally to provide the maximum flexibility in the dial plans. Dialing three, four, or five digit numbers beginning with anything else would have routed to extensions that were local, remote, or special.

Our preferred dialing plan works just like a smartphone. It is interesting to note that people w/o a lot of cell phone experience still dial 1 as a prefix, whereas the younger generation don't. The system doesn't care, it strips the 1 off. But it is just interesting to watch the age gap at work.

We get a lot of resistance to our cell phone dial plan. "Our people have been dialing 9 for years, they will never adjust." Really? You don't think they will figure it out? I say, "I've spoken to your employees, they're pretty bright, I think they can handle it." Nope.

And people freak out about the 911 service. You tell them they have to dial 9911, and some will say "is that legal?" Like the phone cops are going to show up and arrest them.

[Brian Elfert]

I still find myself after nearly two years dialing a 9 for an outside line when sending a fax. I don't do it with my desk phone, but I do on the rare occasion I send a fax. You would think I would have learned having been in the initial pilot group who went on the new phone system months before the rest of the company.

[ray hampton]

If you make a cell call , the call go to the close-by tower [not long distance ] and get route tower to tower,
when 911 come out people would dial 9ii or 9II and someone got the bright idea to teach people how to dial, pay close attention to the spacing between the character 911 and 9II
I had trouble seeing the different between a I and 1 both a double 11 or II will be easy if I remember this
911 = nine one one
9II =nine eye eye

[Steve Peterson]

I blame the guy that designated dailing a 9 for an outside line. 911 would have been defined in the days of rotary phones. A 9 would be a long pulse, followed by 2 very short pulses. I wonder why they couldn't have used the code for SOS (short, long, short). This could have been either 191 or 101 on a rotary phone.

Steve

[Eric DeSilva]

Rotary phones didn't use pulses like that--the phone interrupted the circuit each time the rotary passed by a number, so "9" was actually nine short pulses. On old rotary phones, you could actually dial by hitting the button to hang up quickly X times for digit X, pausing, then doing the same for the next digit. That said, 1-1-1 would have been a better technical choice because it would have been the fastest to dial (least number of pulses to process), but a leading "1" was already designated as the long distance indicator.

[Pat Barry]

IT people are always wrong, at least that's a very common, user, viewpoint IMO. IT/IS does not do value added work, they just make things complicated and make things harder to do because they do so much to guard their own system that they don't care what the users need. So who's to blame? In our company, we use the 9 to dial outside, just like you described but all emergency calls get directed to local security on a special number that is posted on every phone. Talk to Ma Bell, they invented the 911.

[Art Mulder]

I think what I was saying is that the choice of "9" to access a line for a PBX could just have easily have been "8", for example. I'm assuming they used "9" because it allows you to assign PBX extensions from 1000 through 8999 continuously, rather than 1000 through 7999

I work at a university and my extension begins with "8". Actually so does most of my department's extensions.

On a modern digital system couldn't they just as easily have designated "#" or "*" to get an outside line? Heck, I've got 13 other buttons on my Cisco Voip phone on my desk, so they could have easily used another.

But then... I've never, ever dialled 911 erroneously. I'll have to ask around here and see if anyone else has. Especially the folks in the main office, who I bet dial long distance a lot more than I do.