nanog mailing list archives
Re: phone fun, was GeoIP database issues and the real world consequences
From: Jay Hennigan <jay () west net>
Date: Wed, 13 Apr 2016 22:22:46 -0700
On 4/13/16 8:54 PM, Peter Beckman wrote:
On Wed, 13 Apr 2016, Jay Hennigan wrote:
When either of those people dial 9-1-1, where does the ambulance show up?I suspect your response was sarcastic, but when you dig into what really happens, it's not nearly as sophisticated as one might hope. If the numbers are land or VoIP lines, and the address associated with the numbers are registered with the Automatic Location Information (ALI) database run by ILECs or 3rd parties to fetch the address keyed on the calling number, and the 911 PSAP is E911 capable, they operator will see the ALI address.
If they're land lines, the NPA/NXX will be local to the CO so you won't have out-of-area numbers other than a rare corner case of a very expensive foreign exchange line. If they're VoIP lines, the address is *supposed* to be so registered, but softphones and even VoIP handsets tend to move around without the user considering 9-1-1.
VoIP was the scenario to which I was referring. A VoIP phone native to 408-land that moves with a remote office worker to Boston without a conscious effort on his company and VoIP provider to track it down and update ALI will reach a PSAP in San Jose or thereabouts. The PSAPs have forwarding capability but generally only to neighboring PSAPs with a single button. How quickly will they be able to get the call routed to Boston, if at all? And as we saw at the beginning of the thread, forget geo-IP. The ambulance goes to the Vogelmans' farm. If a remote office worker, it could be VPN back to the VoIP PBX in 408-land anyway.
So, it isn't just IP addresses that aren't easily geo-referenced. It's also phone numbers. The number may start as a well-referenced PRI going to an IP-PBX after which all bets are off. If the ANI is the company's HQ main number where the PRI and IP-PBX are located, then it's just about impossible to route 9-1-1 from a worker's IP phone in Boston to the right PSAP.
If they are mobile devices, it depends. Basic gives you nothing (all phones since 2003 should have GPS, but people hang on to phones a long time..);
Mobile is a separate case where it's expected that the NPA-NXX isn't going to be tied to a location. In California, mobile 9-1-1 goes to the CHP and not the local PSAP based on the cell tower or GPS for that reason. If not a traffic incident, they forward to the appropriate PSAP based on the caller's info or perhaps whatever ALI (or estimate) they get from the cellular provider.
-- Jay Hennigan - CCIE #7880 - Network Engineering - jay () impulse net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV
Current thread:
- Re: phone fun, was GeoIP database issues and the real world consequences, (continued)
- Re: phone fun, was GeoIP database issues and the real world consequences John Levine (Apr 27)
- RE: phone fun, was GeoIP database issues and the real world consequences Matthew Black (Apr 27)
- Re: phone fun, was GeoIP database issues and the real world consequences John Levine (Apr 20)
- Re: phone fun, was GeoIP database issues and the real world consequences Dan Lacey (Apr 20)
- Re: phone fun, was GeoIP database issues and the real world consequences RT Parrish (Apr 24)
- Re: phone fun, was GeoIP database issues and the real world consequences Leo Bicknell (Apr 18)
- Re: phone fun, was GeoIP database issues and the real world consequences Eric Kuhnke (Apr 18)
- Re: phone fun, was GeoIP database issues and the real world consequences John Levine (Apr 18)
- Re: phone fun, was GeoIP database issues and the real world consequences Jay Hennigan (Apr 13)
- Re: phone fun, was GeoIP database issues and the real world consequences Peter Beckman (Apr 13)
- Re: phone fun, was GeoIP database issues and the real world consequences Jay Hennigan (Apr 13)
- Re: phone fun, was GeoIP database issues and the real world consequences John Levine (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences Owen DeLong (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences John R. Levine (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences Larry Sheldon (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences Jean-Francois Mezei (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences Owen DeLong (Apr 14)
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- Re: phone fun, was GeoIP database issues and the real world consequences Jonathan Smith (Apr 14)
- Re: phone fun, was GeoIP database issues and the real world consequences Peter Beckman (Apr 13)
- Re: phone fun, was GeoIP database issues and the real world consequences Jean-Francois Mezei (Apr 13)
- Re: phone fun, was GeoIP database issues and the real world consequences Owen DeLong (Apr 13)