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FreePBX (MeshPhone) Office Code

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N5MXI's picture
FreePBX (MeshPhone) Office Code

I'm attempting to setup FreePBX with the MeshPhone configuration. Who assigns or how can I determine what my "office code" is? What is my npa?

In the Sorry Message, change the digits 97321 to be your npa plus the; first digits of your local extension range. This is called your "office; code".


N2MH's picture
Office Code Derivation

Your 5-digit Office Code  for MeshPhone is built from two sources: your area code and the first part of your extension number range.

1. Your area code (probably 361) forms the first 3 digits of your Office Code. In the telephone industry, NPA (Number Plan Area) is the official term for "Area Code".

2. Depending on the length of your extension numbers, the remaining 2 digits of your Office Code may be either

- the first two digits of your extension number range (for 4-digit extension numbers)
- the first digit of your extension number range (for 3-digit extension numbers) prepended with another digit to make your 3-digits unique with other 3-digit extension ranges in your network code.

As an example, I live in Area Code 973 and my extension range is 2100 thru 2199. Thus, my Office Code is 97321 and my MeshPhone numbers are 973-2100 through 973-2199.

Please note that the use of Area Codes for MeshPhone network locations is simply for convenience in predicting/assigning network location codes. It has no connection with the public telephone network other than the fact that AT&T did a good job of developing them back in 1945. No part of the public telephone network is used for MeshPhone.

Mesh PBX office code routing
     Mark, this is a great concept, to actually get some standardization in the dial plan across the entire Ham Mesh PBX network.  While adhering to the standard you indicate to derive each sites NPA and office code, how are you proposing to route these calls?  I have been away from AREDN Mesh for a while so I may have missed some other documentation related to this, but it sounds quite interesting and I'd like to know more. 
73, Bill, N4SV
N2MH's picture
Trunk(s) and Routing Table


As I mentioned in an earlier post in this thread, the 7-digit MeshPhone number is made up of a person's Area Code plus 4 digits corresponding to his local extension number. Calls get routed to other PBX(s) via a dedicated IAX trunk to those PBX(s). The 7-digit MeshPhone number is sent over this trunk. When it gets to the far-end PBX, it goes into a routing table that inspects the number coming in and routes it accordingly:

- to a local extension
- to a PBX further down the network
- to an error message that includes the Office Code for that PBX.

This inspection takes place using built-in asterisk digit handling code, which includes stripping or adding of digits, as needed.

Depending on network topology, any PBX can trunk to other PBX's. Thus, any pbx does not need to have direct connectivity into all other PBX's. It only needs connectivity to get to another PBX that can route his call.

Outgoing calls are originated by the user dialing an access code of 78, receiving another dial tone, then dialing the 7-digits to reach the desired party. This call hits the same routing table as incoming calls and gets routed appropriately.

A lot of this is spelled out on my Mesh webpage called " MeshPhone VoIP Network Info" which I think you should be able to see. That web page will take you to a series of other Mesh web pages with more information.

Yes, a lot has changed. We'll be happy to get you on board. Among other things, once you are on board, you can participate in the weekly VoIP net on Monday nights (US).

73, Mark


Trunks and routing URL
     Mark, I don't seem to be able to locate the web page info you reference on MeshPhone Network info, would you mind sending the link.

73, Bill
N2MH's picture

Bill, try this:


Note: this is a url that works only on the Mesh and only if you can see my nodes, N2MH-xxxxxxxx. I do see two nodes from you on my network. So, I would expect that you can see my nodes.

If you would like some one-on-one help, please contact me by clicking on my callsign above my logo in this message and then going to the Contact tab.

73, Mark, N2MH


AA7AU's picture
Public URL available?

For those of us not connected/tunneled, would you have an external public URL for that (what looks very valuable) resource?

- Don - AA7AU

N2MH's picture
Not at the present time

At the present time, there is no public URL for this information. However, I am working with the AREDN Web Team to develop a place for it here on the AREDN website. As you can imagine, it won't happen soon, but it is definitely in the works.


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