If you just Googled V&H, Coordinates, CLLI, CO, Central Office, FCC, NECA 4, or any combination, you just found this page.

I had an interesting problem today that required a lot of research about off these subjects.  I wanted to document what I learned today before I forgot it.

Where I work we get T1 circuits for a really low price, but with one condition, the Central Offices that serve each end must not be more than 25 miles apart.   We've used every inch of this for a group of locations in the south end of our County. 

When I ordered another T1 in one of the edge COs, this time I was told that it was too far away to get the great deal.  We would have to pay full price for the circuit.   Since this a factor of almost 5 more expensive, some research was called for.  I begged, pleaded, but I got "It's not us, it's the FCC, you have to understand, we MUST follow the Tariffs".  When I mentioned the other sites that had the low rate, I was told they were being billed wrong.  So by finding this one, I may have just increased about 5 more circuits five fold. 

When you deal with any phone company, you're going to hear 'Tariff' mentioned in about the same way as "Bible" in a church.  It is the basis for their regulated business.  It's subject to misinterpretation, there can be contradictions and people always want to use it to their advantage. But it's usually kept just out of reach of the typical customer... so there's also the element of faith.  I won't say that this subject is a secret part of the phone company, but it's sure not the most public part either.

Side note... One time, at another job, I had to look something up in the Tariff to prove a point.  Keep in mind, this was in the dark ages, BI (Before Internet).  When I found out that there was a law that said that the Tariff had to be made public, I asked the Telco where I could go see it.   Where was it in all of Miami?  Downtown?  No.  Their local HQ?  No.  It was only available in the payment office in the WORST part of town.  One of those places where the homeless want some money, in advance, to make sure your car doesn't get damaged while you're inside.   There it was, in notebooks, about 4 feet wide.  But no search engine.  Cost?  Coins for the parking meter and $5 for the protection money.  True story. 

When you order circuits from the phone company, they will often bill using air miles.  Back in about 1960, an engineer came up with a system to make it easy to calculate the mileage using a simple slide rule.   Tradition dies hard in the telephone industry, so we're still using the same system today. 

Each Central Office, also known as a Wire Center, is assigned a V&H (Vertical and Horizontal) coordinate.  Picture a big grid over the continental US.  10,000 by 10,000.  While there are long formulas to convert to and from the much more common Longitude and Latitude, it doesn't matter.  The phone company still used V&H.  Here's some history on the V&H system.  Here's the slide rule formula to find the mileage between V&H coordinates.  I haven't done it yet, but it looks like this formula could be used from inside Excel or maybe even Access to come up with the mileage yourself.  If you're a programmer and you want to go to and from longitude/latitude, there are some links to sample code.

So, how could the distance between two COs suddenly change?  A full day of digging and I found out.

The local Telco told me the V&H coordinates involved and that they checked and double checked, the distance was more than 25 miles.  Sorry.

I checked a few web sites and they calculated the distance as either 25.000 or slightly less.  In the official calculation, there's a lot of rounding up, so I have to go with the 25.000 value.  Either way, these sites agreed with me.

Here's the data I got from the Telco:

Some other web sites I found showed almost the same.. but not exactly

Could being off by one really cause so much difference in cost?  Yes, because we were already at the edge when we got that contract.  I found out that 1 is about 1/3 of a mile. 

So my mission now was to find out how that 0 became a 1.   This is where it gets interesting.  Everyone at the Telco and all the web sites I could find just mention the source of these numbers as 'The Tariff' or the "FCC NECA 4 Tariff" Every search to see this mysterious document ended in an order form.  I would have to pay at least $500 to even see it.  But doesn't every document ever written by man exist somewhere on the Internet? 

The source for this Tariff is a organization called National Exchange Carrier Association. 

"NECA has administered the Federal Communications Commission's access charge plan for more than twenty years.  Our expertise includes rate and tariff development, industry database management, economic forecasting, trend analysis and regulatory policy analysis."

They appear to be an organization to coordinate the charges between telephone companies. They then submit their data to the FCC. But as all the little padlocks show on their web page, you have to be a member to get much help.  I wanted to know the V&H codes without having to ask my vendor each time.   Seems like a simple thing to look up.  But not really.  At least this site wanted money to let me find what I was looking for. 

What do I know at this point?  Well, my phone number.  Let's see what that can get us.  NPA-NXX is the first 6 digits of your phone number.  Usually, all the numbers in one NPA-NXX are in the same Central Office.

There are a few sites that will help, but this one came up first in Google:

Marigold  If we search by NPA-NXX for 305-468 we'll see the CLLI code for that CO is MIAMFLPL. 

DSL Reports lets us do the same look up.  Scroll all the way down to see the CLLI code. 

What else can we learn from this CLLI code?  Here's the Telcodata site where you can enter in the code and find out more.  There are all the other NPA-NXXs served by your CO.   There could be more than one Central Office switch in each CO building, so there are longer CLLI codes.  Scroll down to our NPA-NXX, 305-468, then click on "Detailed Switch Info"  Now we have all 11 digits, MIAMFLPLDS0.  Even the address and a map to find the CO.  Even the V&H

Lat/Long: 25.80815, -80.33898

V/H: 8361, 557

Now we're on to something... these people seem to think our CO is at V 8361.  That's where we want it to be!  Why does the Telco think it's 8360?

Side note:  This page also shows the made and model of the CO switch.  "Switch Type: WECO 5ESS (Digital)"  Keep this bookmarked if you ever have to do an ISDN circuit.  Your settings will often depend on this information.

More digging will require access to what I'll call the HT, Holy Tariff.  The author doesn't seem to want me to see it for free.   So who will?  

Part of the NECA's mission is to file the Tariff with the FCC.  So maybe they have it?  

The FCC's web site is great when you know where to go.  They've done a great job with making all the data available.  But finding it can be a real challenge.  I'll save you the gory details on the search, so just go here:

National Exchange Carrier Association, Tariff FCC 4.

NECA has to file this monster document with the FCC electronically, and the FCC seems to have a great policy to post all filed documents on line. Here's our way to get to the data for free.

We're still not there.   More digging.  Start with the most current filing.  Click on the link to see the Administrative Sections.  436 pages in this one...  Do an .pdf search for "SERVING WIRE CENTER V AND H COORDINATE INFORMATION - FL" or sub your state's 2 letter postal code.

Take note of the number to the left... in my case 21.   That's going to help us find another document.  Back up to the list of all the documents.  Look for "Wire Center Sections xx-xx." and click on the document with the range that includes the number from the last step.  In my case "Wire Center Sections 12-36."  Get that document open.   You might want to get some coffee while you wait.  2874 pages to look through.  Again, let the .pdf search function do the walking.  Enter in that CLLI code from before, MIAMFLPLDS0. 

See that 08360?  That's the problem!  The 0 there puts it too far North and over the 25 mile limit we have.  How could this be?  When did it change?

So, back the list of all the documents.  Going back a few months, open another one, search for the CLLI code, check the WCV data, go back a few more months, search for the CLLI code...  Wait, this one is different:

NATIONAL EXCHANGE CARRIER ASSOCIATION, INC. TARIFF F.C.C. NO. 4
DIRECTOR ACCESS TARIFFS/ACCESS PLANNING 231ST REVISED SECTION 21
80 S. JEFFERSON RD. CANCELS 230TH REVISED SECTION 21
WHIPPANY, N.J. 07981-0918 PAGE 113
ISSUED: APRIL 14, 2006 EFFECTIVE: MAY 01, 2006
WIRE CENTER AND INTERCONNECTION INFORMATION
SERVING WIRE CENTER V AND H COORDINATE INFORMATION - FLORIDA
LOCALITY CLLI WCV WCH CC LATA OFFICE TYPE
---------NPA/NXX---------- ----------- ----- ----- ---- ---- -- -- -- --
MIAMI MIAMFLPLDS0 08361 00557 5191 460 AA BA DA GC
305/214,268,309,392,406,418,436,437,463,468,470,471,475 GD GL GQ GR
305/477,478,482,499,500,513,514,566,568,578,591,592,593 PA PJ QB QF
305/594,597,599,629,639,640,697,715,716,717,718,739,941 RC RD RH SV
305/994 T9 TJ TK VG
786/331,336,464,533(4000-5999),533(7000-7999) XA XD
786/533(9000-9999),845

So... sometime between April 14, 2006 and December 15, 2006, the NECA 'moved' our local CO north by 1 V number!  I drive past this CO twice every day and I can assure you, it hasn't moved an inch.  No earth quakes or land slides here in FL, so they can't blame that.   If your CO has moved a whole digit, I suspect you have bigger problems anyway. 

My next step was to let the Telco and NECA know what I found.   I'm waiting for a response.  I'll let you know how things develop.