Asterisk with Alarm Panels


I know it is not recommended, but for over a year I have been running multiple alarm panels through our PBX server. They have been working wonderfully. Up until the past 2 months apparently.

According to one of the alarm techs that showed up randomly at one of our locations. The signals are just not coming through properly. They are in fact coming in “jumbled” are his words.

We are using a older version of asterisk, free pbx, centos. Since there is no direct upgrade too the latest distro.

Here is the information I can provide:
OS: Centos 5
Asterisk: Asterisk
ATA: Cisco SPA112 firmware 1.3.1 (003)

I truely don’t know what could be causing this now. As abitger alarm company we are using is getting signals just fine.

I can only assume they changed something on their side. Anyone have any ideas i can try to look at on my end?

Obviously something has changed to cause the problem. Alarm panels have a number of different formats and ways they can communicate, but often issues like noise/jitter and echo can have the biggest impact. Have you noticed any call quality issues come up recently? Also make sure the ATA has all of it’s “built in” feature codes disabled, as some alarm panels communicate using DTMF tones that the ATA may interpret and “gobble up”.

If you’re in good standing with the alarm tech/company, you should be able to ask them to try a different communications format. Some like SIA are based on frequence/key shifting, while others like ContactID are based on standard DTMF tone sequences. We use SIA for all of our customers, but as long as your have your ATA configured properly ContactID should work just as well…

There has not been any changes in call quality. He have had a increased call volume lately, but the asterisk server is using a dedicated 60MBps DS and 10MBps US connection and we have not noticed any drop in quality or lag.

It was working very well until about 2 months ago aparently. They in fact didn’t even realize we switched the alarm panels over until they showed up at one of our locations today check on why the panels were acting the way they are.

I do have all the feature codes disabled that it will let me in the ata. Including all the codec switch codes.

The alarm company in question refuses to assist us in this matter. As they do not support digital lines. It took me 3 weeks of prodding them just to get them to tell me that they use ContacID instead of SIA.