[VoiceOps] Rate Center Maps, Locations for NPANXXs

John Todd jtodd at loligo.com
Mon Sep 20 14:43:51 EDT 2010

Peter -
   I strongly suspect that you describe below a systematic problem  
with switch/NPAXXX mapping, as you indicate.  The exact example you  
use may be a bit misleading as to the extent of those errors, though.   
Bear in mind that the DC area has some very strange things in their  
phone mapping, in particular, the Beltsville CO which you identify.   
There are facilities served out of the Beltsville CO which are, shall  
we say, "non-standard".  The Arlington exchange you reference may be  
significantly farther away from the switch than is typical.  The  
Beltsville CO may show some unusual mappings; I would suggest you  
don't use it as an indicator or test case given the number of  
technically complex government use cases in that area.

   The first (or second?) data T1 we had almost installed in our  
office in Beltsville was an interesting example, though not directly  
voice-related.  The Bell Atlantic technician wired it up into our then- 
empty building, and asked "Is the tech at White Sands available to do  
an end-to-end test?"  Since we were expecting a T1 to go about six  
miles down the road, this was a surprise.  He looked at the expression  
on our faces, looked back at his paperwork, and said "Whoops.  Let me  
get back to you in a few hours with YOUR circuit."

   Lastly: Your phrase of "inconsistently and automatedly get the data  
I need" is a truism for number-to-geography mapping these days.   
Ultimately, there is a growing lack of geographic association with  
numbers, and the relative value of doing that association is  
diminishing.  For instance, I have no phone numbers associated with me  
on a common basis that mapped to a switch that is within 2000 miles of  
where I sit most often.  While I am a phone geek, this is growing more  
common even with friends who are not in the telephony industry.  Other  
than an increasingly inaccurate curiosity (pretty maps with lots of  
lines!) I don't see much use for geographic association in the future.


On Sep 20, 2010, at 11:08 AM, Peter Beckman wrote:

> In the past I've paid MelissaData.com $400 or so to get access to  
> their
> NPANXX-Ratecenter-Location-GIS data.  For each NPANXX, they list the
> Ratecenter, City and state/region, Lat/Lon coordinates.  It's fairly
> accurate, though I'm not entirely sure how they get the data.
> TelcoData.com doesn't keep City/State or Lat/Long coordinates of the
> NPANXX, only the switch that serves the block.  The problem is that,  
> for
> example in DC, Washington DC Zone 17 seems to be served from  
> Beltsville,
> MD, but 571-269-3 is a Virginia, likely Arlington, exchange.  So  
> taking the
> switch location as the lat/lon for the npanxx block is very incorrect.
> Cloudvox's API is awesome (Thanks Cloudvox!), but outside of Country,
> Region and Ratecenter, the city and location data from their API has  
> been
> somewhat wrong.  Examples:
>    http://digits.cloudvox.com/571/269/3
>    Ratecenter: WSNGTNZN17 VA
>    City: WSNGTNZN08 (what?!?)
>    Lat/Lon: 37.4315734, -78.6568942 (the center of Virginia, not even
>    close to the DC area)
>    http://digits.cloudvox.com/805/316
>    Ratecenter: SNLUSOBSPO CA
>    City: SANBARBARA (Not a valid city name)
>    Lat/Lon: 36.778261, -119.4179324 (155 miles from San Luis Obispo,  
> CA)
> There are others, but I won't bore you.  To give them credit, they  
> have a
> "geo_precision" which I assume tells you how many significant digits  
> you
> can trust, but is not mentioned in the API docs
> ( http://help.cloudvox.com/faqs/digits/digits-phone-number-location-lookup-api 
>  )
> Plus it is limited to US only (recently addressed here or on  
> asterisk-biz,
> may change).
> LocalCallingGuide.com is a bit better at their lat/lon, but they don't
> include City name, they only offer XML and not JSON or another  
> parseable
> format, and they don't list the ratecenter in the LERG 10 char format.
>    http://localcallingguide.com/xmlprefix.php?npa=571&nxx=269
> I'm expecting WSNGTNZN17, not "Washington Zone 17" as the Ratecenter.
> Between the TelcoData.com, three, I can inconsistently and  
> automatedly get
> the data I need.  I'd like to start offering a map of numbers  
> available,
> but the map is only as good as the data behind it.
> Is there another more accurate source that people use?
> Beckman
> ---------------------------------------------------------------------------
> Peter Beckman                                                   
> Internet Guy
> beckman at angryox.com                                 http://www.angryox.com/
> ---------------------------------------------------------------------------
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