Re: [telecom] Number length, was Goodbye to copper? [Telecom]

Automated routing over the most cost effective trunk lines. Should a call go out over a regular line, an instate WATS line, outstate WATS line, FX line, tie-line, etc.? If the primary choice isn't available, what is the best second choice?

I suspect these choices were more significant in 1999 than they are now.

I can provide one reason: anal-retentive management at some companies. :-)

Real example at one client company in the San Francisco Bay Area: they'd permit "local" calls from any phone to communities where employees lived, restrict long distance dialing to those with passwords in the LD file, and restrict international dialing to those with passwords in the INTL file.

Thus, I had to setup those (asterisk) files so "local" calls would be those in the 415, 650, 408, 707, 831, 510, and 975 area codes, and all other calls would be denied without a password being entered. Many of those weren't "local" in the billing sense because some people would commute 100 miles a day.

Ah, just remembered, 800, 877, 866, etc. were permitted, too, without a password, as was 911. :-)

PBX's must have these for any dial restrictions they assign to the various groups of extensions that they have.

Basically they need to know what is Local, Long Distance, International etc.

Extension restriction is an ancient function of dial-PBXs. The simplest, of course, is restricting who can dial outside calls. That feature is still in use today, such as for hallway phones and the like that. Years ago employees and visitors who wanted to make personal calls had to use a pay phone. Most large businesses had payphones for employee or visitor use scattered throughout the building, such as one near the restrooms on every floor, several in the cafeteria and of course in the entrance lobby. (Today, when a large building often won't have a pay phone at all, it's hard to believe how many payphones were installed in buildings).

According to the Bell Labs history, in the 1950s they developed a toll restriction, that is, an extension could dial local calls but not toll calls. This was done in the central office; apparently certain dial-9 PBX trunks were assigned to that class. The central office of course maintained up-to-date tables. I worked in a large hospital that had that service. Most extensions could not dial out at all. Some extensions (and patient room lines) could dial out locally. In those days all toll calls went through the PBX switchboard where the attendant requested time & charges and prepared a toll ticket of the calling extension.

(I suppose one can still ask for time and charges on an LD today, but the operator handled-surcharge would far exceed the cost of the call.)

One feature of Centrex was that each extension had its own billing, so that toll calls were automated billed back to the proper extension, eliminating the need for the PBX attendant to write up toll tickets. (Some Centrexes were served by ONI offices.)

Since toll calls are so cheap today many of these features are not significant today, but they still are in use. Business long distance still has a charge to it, and certainly international calls do.

I would say so. My Vonage primary number is in Washington DC. I am in Southern California. This arrangement is the fucntional equivalent of a transcontinental FX line, which would have cost several thousand dollars before the Internet blossomed.

That's a great idea: whenever you're feeling down, you can dial the local weather. ;-)

Bill

That's what I love about VoIP. It doesn't care where you are geographically, your phone numbers is always the same.

There's a downside to that: ascertaining the location in an emergency.

Let me clarify.

One evening at work I was interrupted by the Building Manager accompanied by two local Police Officers claiming someone had made a 911 call from our floor. Surprised (thinking I was the only one still in the building), I asked them for the number, then ran to the phone closet where I had a floor map with the location of every phone (in the NorTel/BCM system) and found it to be in a conference room.

Running over to that room with the officers, we found the auditors still at work and claiming they made no phone calls. Satisfied there was no emergency, the officers left.

But I checked the phone logs and a call was made, recorded as 911. What I believe happened is the auditors thought they had to dial "9" to get an outside line, then dialed some digits beginning with "11" (probably a typo since I cannot think of any valid long distance or international number beginning with "11").

Point being: knowing the number, I knew the hardwired location.

With cellphones, a (rough) location can be gleaned knowing which tower(s) is/are being used.

How can (or does) a 911 call using VoIP provide a useful location? I ask because that same company, after they were "forced" to "upgrade" to a VoIP provider halfway across the USA, had their VoIP phones' IP addresses assigned by DHCP from the provider 1500 miles away. The provider wasn't clueful, noone else shared my concern for 911 handling, the company soon went belly-up, and I ceased worrying about them.

But I do worry about 911 handling in the general sense after an episode years earlier when I "made the rounds" of another client before leaving for the night and discovered one person on the floor in his cubicle. 911 brought immediate response and the paramedics stated the person had passed-out from appendicitis and my call saved his life. Ever since, I always "walk through" a client's suite, floor, or building before leaving for the day because I'm usually the last person out the door.

Not everyone has unlimited long distance and can freely make multiple or chatty long distance calls. The meter is running and the bill adds up.

If you're out of your home area and you want someone to call you, through your home area, it could be a toll call for them.

I thought modern cellphones had GPS location which was always transmitted to a 911 center. (Whether the 911 centers have the ability to use this info is another question that needs to be asked.)

Cellphone towers aren't much help in determining location--even in dense areas the call could be handled by a distant tower. (I made a calll shown as using a tower in New York City even though I was no where near NYC. I make numerous calls from a fixed location and they show up as handled by at least _four_ different towers, that is one day it's point 1, another day it's point 2, etc.)

Vonage requires uses to enter their physical address into their system before allowing 911 calls. This is used to route 911 calls to the proper PSAP based on location, not phone number. The provided address is also passed to PSAPs that have e911, so the emergency services show up in the right place.

In my opinion, Vonage goes to a reasonable effort to make sure subscribers know they must go through this step to allow proper 911 operation, and to make sure subscribers know to update the address if they move the VoIP terminal. You can read their TOS and see for yourself.

I'm not sure how other VoIP providers take care of this, but I suspect it isn't too different.

-Gary

The subscriber has to have sufficient brain power to understand that the VOIP location has to be kept current with Vonage.

In any case, I also have an LEC wireline phone, so that is a non-issue at my residence.

Although my primary number is in Washington, DC, I have a virtual number that is local to my actual location. And, unlike the local LEC I could select a virtual number that is local to my town and to a friend 30 miles away who otherwise would have to make a local toll call to reach me.

and

And that's the present flaw with VoIP and emergency calls: action by the user is required to establish present location. Assuming a user will always update the location is, well, an assumption, and most of us are probably aware what Benny Hill said about assumptions. :-)

A passive system, perhaps using an embedded GPS chip, would seem "best", but my experiences with GPS reveal the signals don't penetrate much of today's infrastructures (e.g., steel-framed buildings, thick masonry, etc.) and, thus, cannot be relied upon. Perhaps a combination of GPS and inertial sensors such as these could infer the location based on detected movement since the last successful GPS acquisition as we read on PNI's site:

" PNI sensor modules allow autonomous and remote-operated vehicles to navigate " accurately underground, indoors, and anywhere GPS is compromised or " unavailable.

Something for the next generation of VoIP devices. Technology is a moving target.