Intertel/Axxent Protocol


What protocol does the Intertel Axxent key system use to communicate with its phones (Standard Digital Terminal P/N: 550.4400)?

I currently am “the it guy” for a small company (~60 people), and our phone system is on it’s last legs. I spend a lot of my time babysitting it, and that takes away from the time I should be spending on other endavors. Unfortunately, we have little to no budget to properly upgrade the existing system. We do have the appropriate hardware, I believe, to run an Asterisk system, if I don’t have to replace the phones. I know that the phones don’t use standard PSTN signaling, but I can’t find out if they use something completely proprietary.

Has anyone out there managed to replace an “Axxent” system with an Asterisk PBX without changing out the phones? If so, what channel protocol did you use? I have a feeling that it won’t work, but I read something out there that gave me some hope that they possibly use MGCP for their channel.

Anything that anyone can offer would be great, including telling me that it just isn’t possible.

Thanks in advance.


I too am asking this question. We have an old Axxent system with Inter-Tel digital end point phones (24). We need to upgrade and I would like to use Asterisk@Home and keep our phones…any body with clues on how to do this would be thanked very much :laughing:
Joshua Delcore


I haven’t worked with Inter-Tel phones for some time, but I don’t think they ever put VoIP phones on the Axxent system. Therefore, any DIGITAL phones you have connected to your Axxent system use a proprietary protocol known only to Inter-Tel and you cannot connect them to your Asterisk system directly.

With that said, you could play a trick on your Axxent and Asterisk systems just to save the price of hardware on the phones. Basically, you would configure some loopstart trunks on your Axxent system, and you would physically connect those loopstart trunks to a TDM400 on your Asterisk system. Within asterisk, you would configure each of the TDM400 channels as FXS.

To Asterisk, then, the lines to the Axxent would appear as four individual phones. To Axxent, the lines from the Asterisk would appear as four loopstart trunks.

You could then configure your dialplans on each box so that the phones connected to the Axxent could talk to the phones connected to the asterisk, and vise-versa. Similarly, you could configure your dialplans on each box such that the phones on the Axxent could use the PSTN lines connected to the Asterisk, and vise versa. This would also be a great way to make use of other technology you might have on the Axxent like T1/E1 cards or more densly populated loopstart/groundstart cards.

If you have the hardware sitting around (loopstart or groundstart card on the Axxent side and TDM400 on the Asterisk side), it’s kind of a fun experiment and it only takes a few minutes to set up.

Good luck!


Wow great idea…I will give it a try soon!
-Joshua Delcore