This past holiday season I received as a white elephant gift an older outdoor weatherproof telephone by Allen Tel. Prod. From what I could tell this phone was used at the local community college by the campus police. Unfortunately, I wasn’t able to find a whole lot of information on this model, and its lack of a dial limited what I could do with it.
After it sat idly for a couple of months, I decided I could use it to link my workshop and house together. I already had a payphone from the 80’s sitting in my workshop, and figured that if I created an Asterisks installation then these phones could talk to one another over VoIP.
My plan was to use a Cisco SPA112 adapter on both ends to convert the analog phones to VoIP. I naively thought that the Allen telephone would have a standard RJ11 connection inside of it; however, upon opening up the telephone I was faced with a myriad of screw terminals. Since I couldn’t find the proper documentation for this phone, I decided to poke around inside with a stripped RJ11 cable connected to the VoIP adapter while keeping the headset pushed up against my ear. After a few false positives, I discovered the correct combination.
Pictured to the right is how the connection was made. The green wire goes to a block that looks like “L2” and the red wire goes to the “K” block. I bought an RJ11 to spade terminal cable off of amazon to make the connection cleaner. I then electrical taped the black and yellow wires to prevent them from making any accidental contact with other parts of the board.
Now all I needed to do was connect everything to Asterisk. For this I used the FreePBX Linux install to handle installing Linux and configuring Asterisk. There are plenty of tutorials online that explain this process, however; the gist of it is, after installing FreePBX I configured two extensions, one for the shop, and one for the house. Then I configured the Cisco SPA112 adapters to connect to the FreePBX server.
The only snag I ran into was entering the password into the SPA112 to authenticate it to FreePBX server. On the FreePBX box, in the configuration section for the extension there is a “Password For New User” and there is also a text box labeled “Secret”. I originally was putting in the “Password For New User” into the password section on the SPA112; however, I should have been using the “Secret”. After I resolved that both SPA112’s authenticated and I was then receiving dial tone on both phones.
I was able to call the phone in the house from the payphone in the shop because it had a touch-tone dial on it; however, on the Allen phone, it didn’t have a dial on it at all. To get around this I configured the Allen phone to dial the shop automatically when the handset was lifted off the receiver. It took a little bit of trial and error, and some thorough googling, but I eventually discovered how to configure the SPA112 to do this.
By adding |S1<:100> to the end of the dial plan of the SPA112, I was able to have it automatically dial extension 100 (my workshop) when the handset was lifted from the receiver. For example, if my existing dial plan was (*xx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.) then to have it automatically dial an extension I would change it to (*xx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.|S1<:100>)
This has become a fun way to communicate between the house and workshop without having to venture into the Arizona heat.
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