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POTS / Modem replacement

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BugZap13

Programmer
Dec 2, 2013
30
US
I currently have 4 POTS lines hooked to a Dialogic 4 port modem. The setup is used for employees to clock in/out. Software running on a PC answers the call and prompts the caller for their employee number, etc. The POTS lines are supplied by the Cable company (COX) and are getting more expensive each time the contract is renewed or changed. Secondly there seems to be a problem with various VOIP providers being able to call the analog numbers. The cable provider has traced a call from a clients VOIP phone and the call never gets routed to their system. The caller either gets a ring no answer, a busy signal or it goes through. Not sure where it is getting lost but the client with the originating VOIP phones is not willing to spend any time trying to trace the problem.

I have 2 questions. First has anyone had similar failures with calls originating with a VOIP provider never reaching the cable company? Second is there such a thing as a VOIP to Analog converter where I can replace the cable companies modem with the converter? This would bypass the cable company and I would be able to get VOIP lined from my provider eliminating the cost increases?

TIA
Mark
 
I work on Cisco Call manager. We have ATA that will provide analog dial tone. We have used them to provide temp service when a pots line goes out of service and the phone compay needs to fix the line. We don’t have an issue with calls not going through. But they are not modems.
 
We also have some Cisco ATAs, but prefer to keep fax lines on our legacy AT&T 5ESS, at least for now as we migrate to Cisco phones. The ATAs don't have issues with calls going through, but will still sometimes not reliably send or receive a fax. That's even with the recommended codec settings.

Analog lines from cable companies I thought were a pretty good alternative for faxing instead of line from the CO, but maybe their technology has changed in recent years and the trunks originate as SIP, and SIP is not reliable for faxing.

My home phone service is (sort of) a VoIP provider, Ooma - with an ATA. I tried to make a modem call once, and forget about it. I think Ooma used to recommend at least testing their line with a modem application, like faxes or alarm systems before disconnecting the service from the CO. Then again, I've heard of Magic Jack users say they've been able to use the line for faxing.
 
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Try this (assuming you have internet access where the PC is located)...

1) Create a twillio account*,
2) Connect two Grandstream HT802s or four Grandstream HT801s,
2a) The Grandstream will SIP register to the twillio account and allow the Dialogic modem to send and receive VoIP calls through Twilio's network. This is essentially a whitelist allowing only those Grandstreams to connect.

------------
Try it with one Grandstream and see how it goes.
------------

The great thing about the above setup is -- eventually you can rid yourself of that "Software running on a PC" while keeping the same numbers -- Twillio has amazing IVR build technology that works on the twillio platform or offloads to a platform of your choice.

*- It's likely twillio has some queuing method to allow all 4 Grandstreams to connect to one number -- I'd keep it simple, and get 4 numbers...

C.
 
It's been awhile since I've used them so I don't recall - but if the Grandstream ATAs have a T.38 option (they probably do) I'd enable that.

That, or G.711. I don't know if one is recommended over the other.
 
Software running on a PC answers the call and prompts the caller for their employee number, etc.

So it isn't a DATA modem that is answering, but a Dialogic board that is using voice prompts and keypresses to interact with the employee.
ATA's should be perfectly reliable for this purpose. They ARE NOT usable for modem tones, and somewhat usable for Fax tones (if you lower the speed and disable error correction)

Callers not reaching your current setup may be a problem with the previous carrier not having removed the stale routing and still trying to complete calls on their network, or you may have a Hunt Group issue with your current carrier, perhaps something like the 3rd line in hunt is incorrect, so when you already have 2 calls in the system the 3rd caller hunts to a line that isn't connected to your Dialogic board.
 
So it isn't a DATA modem that is answering, but a Dialogic board that is using voice prompts and keypresses to interact with the employee.
ATA's should be perfectly reliable for this purpose. They ARE NOT usable for modem tones, and somewhat usable for Fax tones (if you lower the speed and disable error correction)

Callers not reaching your current setup may be a problem with the previous carrier not having removed the stale routing and still trying to complete calls on their network, or you may have a Hunt Group issue with your current carrier, perhaps something like the 3rd line in hunt is incorrect, so when you already have 2 calls in the system the 3rd caller hunts to a line that isn't connected to your Dialogic board.
My bad - the initial post does say the callers are prompted to enter information, which is via DTMF. When I saw 'Dialogic 4 port modem' I was assuming data transmission of some sort, The term Modem threw me. I concur with what Tommy said.
 
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