Trouble with Alarm Panel dialer communicating through an AudioCodes mp1288

[dstokes805]

Hello,

I am trying to connect a building alarm panel dialer to an AudioCodes 1288. No matter the settings I change the modem lines don't seem to synch up. I monitor the line connected to the legacy PBX and the communication seems the same. I know there is some delay which is probably causing the issue. I see modem settings in the Audio Codes, but the recommended Fax settings from Zoom seem to be interfering with them. 

Has anyone had any luck when attempting this before. I have also tried with a Grandstream ATA with no luck. 

Thanks,

Derek

[sparrow]

Who's the alarm company?

[dstokes805]

I am trying to work with older Bay Alarm panels.

[cdmiller]

I have the same problem with Bay Alarm panels with Grandstream and Audiocodes.  Any information would be appreciated.  We are trying to avoid replacing several panels.

[sparrow]

If this is strictly a dialing issue? I suggest you download a program called syslog viewer from the Audiocodes website. In your Audiocodes MP1288 syslog settings, point the address to your local desktop/laptop running that application. Then try initiating a call from the panel to Zoom to see what the SIP traffic is doing with the call. In our setup with our local alarm company, we don't use any fax/modem settings on the audiocodes gateway. However, not all alarm companies are willing to make things work with a VOIP provider. When your converting SIP to analog signaling, that transcoding causes early disconnect.

[Vinnie]

Hello @dstokes805 Modems and Faxes over IP are always tricky, especially if you are dealing with older equipment that don't support the newer standards. I don't see any information about the Alarm system but I would suggest first of all to contact them as ask them what is the recommended and what is the maximum speed their modems support because I was reading both, Zoom and AudioCodes documentation and it seems that is one of the things you need to configure. With that information you can try to match what they are asking and prevent the AudioCode trying to negotiation something that is supported by Zoom but not the Alarm system.

• Start limiting to lower speed negotiations; on the "Events Only" parameter: V.32 Modem Transport Type seems a good starting point; below that sems to low, but I guess that depends what the Alarm Company modem supports; look at this: https://en.wikipedia.org/wiki/List_of_ITU-T_V-series_recommendations 
• Make sure the alarm company is not forcing a negotiated "Minimum Modem Speed" that you can't reach with your setup.
• ⚠️Any Fax settings should need to be disabled.
• Use G711ulaw  ( I assume you are in US) and if you see somewhere in the Fax/Modem configuration something that says "Passthrough", that is what you need to select. Make sure no other Codec is selected, it is either G711ulaw or G711alaw.
• I didn't see a Zoom article explain how to set for a Modem but to a Fax, and I can tell you by experience, it is not the same and Modems are "pickier"; this is the Zoom article I saw (https://support.zoom.com/hc/en/article?id=zm_kb&sysparm_article=KB0068185 ) and I would suggest trying something different to what I saw there: Echo Canceller and Error Correction (EC) causes more problems than it solves so if you haven't tried, disable both.
• If there is anywhere something that enables "Compression", make sure you disable that as well.
• Limiting the speed to 9600bps should be fine, but some older lines might need even lower speed like 4800 or 2400 (need to check with your Alarm Company).

Now, from the AudoCode documentation, this are the options you need to try (if you haven't yet), in the same order I put them here:

1. V.152 Support: 
   • https://techdocs.audiocodes.com/session-border-controller-sbc/mp-1288/user-manual/version-740/Conten...
2. Fax/Modem Transparent Mode: 
   • https://techdocs.audiocodes.com/session-border-controller-sbc/mp-1288/user-manual/version-740/Conten...
3. G711 Fax and Modem Transport Mode: 
   • https://techdocs.audiocodes.com/session-border-controller-sbc/mp-1288/user-manual/version-740/Conten...
4. RFC 2833 ANS Report upon Fax and Modem Detection: 
   • https://techdocs.audiocodes.com/session-border-controller-sbc/mp-1288/user-manual/version-740/Conten...

I know it is a lot but good luck; I hope one of this options works for you, and let us know so other people can benefits from your "pain" and save them from "suffering".

Vinnie.