Getting the Cisco SPA-112 working with 3cx 16+

I was just recently tasked to get an old analog adapter working with our newer phone system for a client.

We used it years ago for sending and receiving faxes and it works well. They can be found on Amazon, basically giving you 2 analog ports. In this example we are just setting up line one, but if you need line 2 as well, you just need to follow my step 1 examples.

On 3cx:

You need to create a user extension for the device to use, I created 7000 for my use. Since this device is so old, we'll need to set it up manually but it's not hard at all thankfully.

We just need to take not of the auth info from 3cx, just go to the extension editor for you extension, and take note of the auth_id and password.

SPA-112 setup:

If you hit http://SPA112-IP/ in a web browser you can log into the phone device.

The username and password by default is:

username: admin
password: admin

Once logged in, go to the network tab and static the device if you'd like, or static it in your DHCP range on the router.

Go to Voice tab, once there, there are a few things you need to take care of.

  1. Proxy settings - The proxy is going to be either your 3cx phone system, OR your 3cx Session Border Controller IP:Port combo. in my case it was 192.168.2.2:5060
  2. Subscriber info - Under user id we want to put the users extension. Check Use Auth ID. Under Auth ID and Password fill in the 3cx authentication info you found in the 3cx step.

Once this is set up, click save, and wait approx 40 seconds for the device to reboot. Once rebooted make both an outbound and inbound call.

3. If you need to use this device for receiving faxes, and your provider supports T38, make sure you scroll down a bit and enable T38.

Thanks for stopping by!