New Zoom phone system with analog paging system

[Scottdv]

We recently upgraded from an obsolete ESI phone system to Zoom phone. The Zoom folks recommended we purchase an Audiocodes mp112 ATA device to make the paging system talk to Zoom. I followed the instructions to provision the ATA device and it shows up as being online in Zoom. Normally, when you call into the paging system, it auto-answers so you can send out your message through the paging amp/overhead speakers. Currently, the extension assigned to the ATA just rings and goes to voicemail. Anyone work on something similar?

[Vinnie]

Hello @Scottdv 

I would suggest to connect a regular analog phone into the ATA's FXS port to make sure it is ringing and that you can actually answer and talk. Also I would disable the Voicemail on the ATA Port configuration if possible.

If the test is all fine, it is possible that there is either a cabling problem between the ATA and the Paging system.

There are also other factors to consider:  When an FXS port rings, it does it at a specific frequency and voltage; I can't remember the details but I think is around 25Hz and the A/C voltage goes between 60 and 90Volts so the destination port (FXO of the Paging system in this case) can detect there is an A/C voltage "signaling an incoming call". Take a look to the Specs of the AudioCodes Specs to make sure it is compatible with the FXO port of the paging system.

Although on new analog lines/devices the polarity is not critical, it is possible in this case it is; if you are using a regular Phone cable RJ11-to-RJ11 cable you should be OK, otherwise...check the wiring.

And last but not least:  Analog ports (FXS and FXO) may operate in two modes:  "Loop-Start" or "Ground-Start" and the second one is very dependent of the Wiring/Polarity of the connection:  I have checked and the Audiocodes mp112 is ONLY compatible with "Loop-Start" so you have to make sure your Paging System supports "Loop-Start" as well; sometimes there are DIP-Switches or settings on the devices you need to adjust to change to one operation mode or the other.

I know it sounds "complicated" but I will be happy to help checking if you tell me the model of your Paging System. 

[Scottdv]

Thanks for such a fast and detailed reply. I'm the entire IT department at our school, so definitely more of a generalist that doesn't know as much about these things. The paging system does not have a model number but I've attached a photo. The closest thing on the Bogen website is a PCMSYS3. There is an RJ11-RJ11 cable going from the Trunk port on the Bogen to the FXS1 port on the Audiocodes. Good idea with the analog phone, I'm tracking one down tonight to try tomorrow. Thank you so much for your help! We have school starting next week and it's really a safety issue to not have the paging system up and running.

[crough]

Any information on connecting a GRANDSTREAM HT813 FXO port.  ZOOM configuration is completed.  Just will not take paging equipment off-hook.

[Vinnie]

I have found what it seems to be the datasheet (please confirm):

https://us.rs-online.com/m/d/d266ebbc98b7e76a5f77d5c6d01385cc.pdf

It says that supports (and I quote) "...allows simple connection to loop and ground start trunks, paging ports, and to analog 90V station lines..."; I believe the later is the one that most likely applies to your case, and if the 90 Volts is strictly important, it is very likely the "Audiocodes MP112 ATA" you have might not be in compliance; if you can find a Volt-Tester (or Voltimeter) and measure the voltage output of the MP112 and let me know what it says (those devices typically work at 70 Volts level and that should suffice in theory (but not ideal).

I can't find the manual of the PCMSYS3 to take a look and read more about it. Do you have it?

[Vinnie]

I have found the manual online; as I suspected there might be some "switches" that need to be checked/adjusted. I am not familiar with this device so let me read the manual and I will do my best to help, but be prepared to contact BOGEN Support and ask them if the Audiocodes MP112 ATA is a devices that can actually activate it and if there is something you need to adjust to make it work.

https://www.bogen.com/sites/default/files/2021-02/PCM200c_0.pdf

[Vinnie]

Now I was able to see the picture you sent (it helps a lot, thanks!).
I haven't checked the manual yet but I believe the RJ11 cable is connected in the wrong Spot based of what seems to be the settings:

1. Up Switch seems to be setup to LS (Loop-Start) which is correct as your ATA only supports LS
2. Bottom Switch  seems to be set to "STATION" (Which is what the ATA supposedly is giving you - FXS)
3. The Red-Banded Grey-Cable ( I assume coming from the ATA) is connected to the "TRUNK" Port but I believe it should be connected to the "STATION" port, to match the current Switch Position configuration.
4. I think the 90V NGT RNG says it send a 90 Volts Ringing signal from the Analog Line (ATA) to be detected as an incoming call/connection to be able to answer.
   
   I will take a look to the manual to confirm what I am saying; we don't want to damage anything, although those analog ports are very robust, it is unlikely they will "burn".

Vinnie

[Vinnie]

Hello Again @Scottdv 

Look at the Page 12 of the manual, that should be your correct setup: PBX Station (FXS) Level, Loop Start.

I see in the picture, the cable is also connected to the TRUNK Port but if you read the description in the following Page 13, STEP 2 explicitly indicates to connect it to the RJ11 STATION/90V NGT RNG port which makes more sense for me.

I am convinced you should concentrate on page 12 and 13, and disregard the part in the diagram on which port the ATA should be connected to.

[Scottdv]

@Vinnie I owe you a drink, we're almost there! I can now call in and initiate a page, but the system doesn't hang up when I hang up on my end and get a fast busy signal that doesn't stop until I unplug the RJ11 cable.

[Vinnie]

I would adventure to say it is a setting on the ATA: There is something in traditional telephony called  "Forward-Release" and "Backward-Release" signaling that allows to indicate to the other side when one side hung-up the call. Let's think for a moment because I am not sure what to check:

1. I assume you are calling from a Zoom Phone: It rings, the end-device detects de ring and "closes the circuit" and establishes the Audio-Loop and you can now "speak".
2. For the line to get release, the "Circuit Loop" needs to be open for either of the ends ATA, or Paging; you tested this by disconnecting the cable and it works.
3. The question is: Why the ATA is not "releasing (opening the loop circuit)" of the FXS port when you hang-up the Zoom Phone?
   • Did you configured the ATA as a regular extension?
   • Did you enabled Paging in your Zoom Account? I have never used Paging with Zoom Phone in particular but I got the feeling this is "a must" step.

Here is the information (in case you need it) about how to activate and configure Zoom Paging in your account:

https://support.zoom.us/hc/en-us/articles/14406369394189-Setting-up-Zoom-Phone-cloud-paging

I suspect it might help with the "Forward Release" of the audio channel after you are hang-up the call.

No need for a drink 🙂 

I am happy to help; if I can I will be with you until it gets done. Let me know how it goes.

Vinnie

[Scottdv]

@Vinnie, I changed the disconnect settings in the ATA and everything is working as it should. For a school, a working overhead paging system is super important for safety, and I couldn't have got this up and running without your help. I can't thank you enough for all of your detailed explanations. If you're ever in the Philly area, I owe you a drink!

[Vinnie]

Thanks @Scottdv . I might take your word on that 🙂 but really there is no need.

Education is among the most important pillars for a healthy and prosper society so it was a pleasure to be any help; I wouldn't have never left you hanging alone.
If you don't mind I will ask you for a favor so this post might be of any use for other people with similar requests: Would you explain what was the setting of the ATA that "put the cherry on top" and completed the solution? 
Goo luck on Monday...school already started here last Monday. Having a lot of fun with the traffic 🙂 

[Scottdv]

Absolutely, there was a setting on the ATA (Audiocodes M112) under SIP Definitions/AdvancedParameters/Disconnect and Answer Supervision. I enabled the option for Current Disconnect (screenshot attached). I used the tried and true method of clicking on every single menu option until I saw something that looked like it might be the right choice. That did the trick and I had it up and running about 30 minutes before our first safety drills of the school year. Thanks again and I hope this thread might help somebody with a similar problem in the future.

[DavidMc1]

Just want to say thank you for adding the final setting to this.  Saved me on our zoom implementation with a bogen u1312 used in a library.   Exact same symptoms.

On another note,  we had some help lines on elevators that had the same issue.   This setting fixed those as well.