Alarm system help PLEASE

Hello guys,

I recently gave up my home phone line to replace it with a
GrandStream HandyTone HT701

Which acts as an external extension, and is connected through Internet to my FreePBX / Asterisk server at the office.

Everything works PERFECTLY except the darn alarm system.

The SIP lines I have connected on my FreePBX server are provide by BabyTEL.

The alarm system service is provided by ADT.

Previously it was connected to a “phone” modem provided by Videotron (so it is basically a VoiP service but provided through a big modem that gives you Internet + phone out of coaxial cables)

No prob for finding the wires… the installation is rather simple… there’s a bypass for the alarm system to be able to take over the phone line… and the source wire was connected in the Videotron described above, so I just plug in the phone cable in the FXS port of my GrandStream HandyTone HT701

Anyhow, I can make and receive phone calls with extreme reliability and I love everything about this setup (VoiceMail through email, etc.) and I don’t wanna go back!!!

I would just need some help tweak up my GrandStream HandyTone HT701.

Are there some CODEC that would be better?
Is there any thing I need to set up in the GrandStream HandyTone HT701
in the extension configuration in FreePBX?


Just in case: there’s no “dial out number” or anything of the sort.

From the external extension (the GrandStream HandyTone HT701) you just pick up the phone and dial the number and it works.

Things that use analog lines like alarm system and fax machines typically have trouble tith SIP VoIP. uLaw is the best codec you can use for this but I have never seen it to work 100% like analog lines.

My trunk is already set on


anything else I can do??

I meant:


any help on this?

You were already told Alarm Modems and VoIP don’t mix.

Get a wireless modem for your security system.

Well okay then any recommendations on what company I should choose and where I can get this please ?

I’ve been browsing around but I can’t find any good review website :frowning:

Isn’t there a company out there that allows alarm system signals to go through Internet ?!?

Alarm systems are often very proprietary. A good place to start is with the vendor of the alarm system.

Not all, but some monitoring centers now offer IP monitoring, vs the traditional phone line, and I suspect this is spreading more every day. The last building system I had installed, I made sure the control panel was IP compatible. Some may argue this, but I suspect this for the most part is a superior solution to a conventional line, as it then keeps a heartbeat with the monitoring center, and if they lose it they notify you.

Outside that, and I haven’t used then, but I know at least at one point some monitoring centers would send out a somewhat modified analog adapter that would communicate with them over SIP. As everyone has mentioned, just like with FAX this can all be touch and go, granted the true IP monitoring we have used has been fantastic compared to a conventional line.

The security vendors in our area sell Verizon 3G alarm adapters. The data only subscription is under $20 a month. I think the adapter works with most panels.

are you only monitoring for security or fire as well? If your monitoring fire there are certain city codes that may require a pots line that bypasses any pbx. Some cities will not even permit wireless. check local codes. your monitoring station can usually guide you.