Difference between ATA and DTMF

[Telephoner123]

I'm starting to research how to get my old phones online now that we have canceled landline service at our house.  I keep seeing references to ATAs and DTMF converters.  What is the difference? And do I need both for a rotary phone?

[unbeldi]

ATA stands for analog telephone adapter, which is an electronic device that connects a traditional analog telephone to a voice-over-IP network. They come in a variety of types, some embedded into an Internet-access adapter, set-top box, or they can be stand-alone devices that plug into a local area network switch or router. They all convert the analog signals, both speech and call control or supervision used by traditional telephones into digital forms suitable for a variety of voice-over-IP protocols, such as the Session Initiation Protocol (SIP), and the Media Gateway Control Protocol (MGCP), to name the most common.
With an ATA you can reuse a traditional telephone with voice-over-IP.

Just like old-style telephones can use two different methods to dial a telephone number, namely rotary dialing (pulse dialing) and tone dialing (TouchTone), an ATA may support one or the other method, or both. Dual tone multi-frequency (DTMF) is the technical term for TouchTone signaling.

Most ATAs today do not support the rotary dialing technology anymore, they simply ignore the dial pulses sent from the telephone.  To support this, which is what most telephone collectors need, you have to be careful when selecting an ATA.  The choice is not great.

The alternative to selecting a pulse-capable ATA is to use a pulse-to-DTMF converter between the telephone and the ATA.  Some choices exist, but it appears no one choice works reliably in all situations.

One of the easiest and most reliable choices is to buy an old residential/small business PBX system, such as the Panasonic KX-T30810 or KX-T61610, that are very popular with members on this forum.  These can cost less than many single-phone converters, while connecting either 8 or 16 telephones, whether they use tone dialing or rotary dialing.

[Jim S.]

One of the easiest and most reliable choices is to buy an old residential/small business PBX system, such as the Panasonic KX-T30810 or KX-T61610, that are very popular with members on this forum.  These can cost less than many single-phone converters, while connecting either 8 or 16 telephones, whether they use tone dialing or rotary dialing.

Also each port can handle 4 phones, this can be handy for intercom purposes. You can have a phone in your home office, Garage, shop and phone booth, and your wife only has to try 1 extension.

JMO,
Jim S.

[Owain]

Also each port can handle 4 phones, this can be handy for intercom purposes. You can have a phone in your home office, Garage, shop and phone booth, and your wife only has to try 1 extension.

But that means it's not possible to dial internally between office and garage. Much better to use a hunt group, or loop one of the extensions back into an unused line and set that line's ringing appearances accordingly.

Or use the paging output to connect to the in-house public address system :-)

[Fabius]

The VOIP service I use is Magic Jack. It's probably the most affordable VOIP out there. I have used them for a couple of years now. They have greatly improved their service. You can plug their unit into a desktop or laptop's USB port or directly into your internet router, then connect the output to your system or just an individual phone. . I renewed all my Magic Jack numbers and it cost $35 a year per number plus about $2 911 fee per line. I also like the fact you can pick your own US or Canadian number. We have a home in Michigan and a small apartment near our kids in Indiana. I use a Panasonic
KX-T61610 in each location. I have Panasonic phones and rotary (WE 302s & payphones) phones. Where there was no hardwiring for a phone, such as a bathroom, I used a cordless phone. I was surprised how often the bathroom phone gets used. The Panasonic is fun to work with and fairly cheap on eBay. I use the default programming as it suits my needs but you can program the system to meet your needs. I also have a CNET line into the system.

[dsk]

We should not just look at internet telephony as an option, but whatever you get pulses from rotary phones are accepted by a minority of other services.  That makes you need something to to convert rotary to touch tones (DTMF) and as mentioned over the PABx's; Panasonic KXT 308 or 616 are great.  Some phones  and pulse to tone adapters do not work well together, but the Panasonic pbx works well.  The trunk line might be an ATA connected to internet, The MagiJack needs a running PC, and you may get a number of adapters where you put in a SIM-card and connect a wired phone, or connects to your sellphone via bluetooth.

dsk

[Fabius]

The MagiJack needs a running PC, dsk

The newer models of the MagicJack do not need a PC to work. I have the newer ones and they plug right into the router and then wired to my Panasonic PEBX. No PC needed.

[dsk]

Great new information about MagicJack! 
dsk

[Victor Laszlo]

Is it possible to port an existing PSTN number to Magic Jack?

[poplar1]

Is it possible to port an existing PSTN number to Magic Jack?

Yes.

[andy1702]

I agree about the Panasonic PBX, they work very well and convert the pulses from old phones to the tones needed by most ATAs flawlessly. I'd advise against using an ATA that accepts pulse dialling directly. The problem is these pulse accepting ATAs are very fussy about the pulses they receive. If your dial is pulsing a bit fast or a bit slow they will easily mis-dial or maybe not dial out at all! It's far better to use a PBX between phones and the ATA to convert the phone pulses to tone. For some reason the PBXs don't seem to be fussy about dial speeds at all. If you do get a PBX you can then have extensions all over the house / garden and you can probably pick up an ATA that's a lot cheaper (PAP2/NA is a popular one) which will almost totally offset the cost of a good second hand Panasonic PBX off E-Bay.

The system I use at home happens not to be a Panasonic, but a BT Revelation. It does basically the same thing though. I have the ability to have four incoming lines, or which I use 3. Line 1 is a normal wired phone line out to the PSTN. Line 2 is connected to an ATA which is set up to have C*Net as the voip provider. Line 3 is another C*Net line connected to a second line provided on the same ATA. I then have a spare incoming line which could be connected to a public voip provider such as Vonage etc which would allow me to use it to call any PSTN number (at a cost) and do away with my wired line 1.

Andy.

[markosjal]

The VOIP service I use is Magic Jack. It's probably the most affordable VOIP out there. ..

The most affordable is Goole Voice. IT IS FREE !

You pay a one time fee of about 7 USD to simonics.com and they handle transcoding to/from SIP 

If you need E911 support that can be added to asterisk or even on many ATAs see GV911.com

I have used Google Voice for years now it is reliable and the simonics.com Google voice gateway is very reliable .

so it costs $7 USD paid to Simonics.com

No monthly fee if no 911 required.

GV911 is 1 USD per month (you can use their dialplan example in Sipura/Linksys/Cisco ATAs although it says it is for Obi device). Grandstream HT 502 manual http://www.grandstream.com/sites/default/files/Resources/ht502_user_manual.pdf , page 56 says you can do string replacents like <2=011> , so change this to <911=1NXXNXXXXXX> , where 1NXXNXXXXXX is the PSTN number GV911 asigns you for 911



PM me if you want more info or help

Mark

[Phonesrfun]

OK, folks, this was a great post.


I tried this out.


Since I already have a Gmail account, all I had to do was request a Google Voice phone number which was immediately given to me based on my city and state.  Initially, the number was tied to either my home or my cell number.  I chose to have it ring on my cell number.


I got onto ebay and ordered a Grandstream HT502, which came within a few days of ordering it.  The Grandstream ATA plus shipping total was under $25


Once I got it, I went to simonics.com and registered and the cost of that was $5.99 and also immediate.  I got the information and put it in the Grandstream and once that all got registered and rebooted, the number was now capable of making and receiving calls as a stand-alone phone.


The Grandstream does support rotary dialing, but it seems to be a bit touchy.  For instance, I need a pretty stable rotary dial.


All in all, for a total all-in cost of $31.00 one-time, it surely seems like a great solution.  Note that I did not do the 911 calling which would cost $1 per month. I still have my other land line so I have no immediate need for the 911 coverage.


This seems like a real reasonable way to get a number and dial tone and a way for collectors to demonstrate phones without going the route of a PBX, although once you get one of these lines, you could certainly connect it to a PBX.  In fact, the Grandstream has two ports, so there is probably no reason you could not get another number registered to it.

[Phonesrfun]

One issue with the thing.  Numerous false ringings... like every 5 minutes, with nobody there and no record of incoming calls on Google.  Did a little googiing and found that apparently the default IP port number is one that is prone to hacking.  True or not, the recommendation was to change the default port which I did.  False ringing has stopped.


I notice that one of the advanced settings of the Gransstream is for reverse battery on call completion.  This could be helpful if one had one of the AE semi-post-pay coin phone hooked up.

[AE_Collector]

I have a bit of an issue with the ability to opt out of 911 service. I saw the efforts we went to make 911 calls from PBX's work in all situations. The problem is that most PBX's have dial 9 for outside service which means a person who is unaware that the phone they grabbed to call 911 in an emergency is a PBX extension OR even if they are aware of that, in an emergency they are likely to go off hook and dial 911 which only dials 11 after grabbing an outside trunk. Precious seconds lost in confusion in an emergency.

We set up PBX's to dial 911 on outside trunks no matter what convoluted attempt to call 911 was made from extensions. So now take this Google phone service that has NO ongoing monthly charge, just a dirt cheap one time charge. Even I would be tempted to avoid the hassle of signing up to get the ongoing 911 service in that scenario.

I pay 9 or 10 cents (Canadian) per month for Greater Vancouver E911 service on my Telco pots line so $1 US per month for 911 service through Google voice is quite simply an outrageous price that will dissuade even more people from doing it. A typical scenario where countless $$$ millions are spent providing the E911 service but large numbers will opt out of the service to literally save a buck.

And finally, Something else that happens is that people have poor memories. A voip line us installed without 911 service because it is just an extra line to the main pots line. Some time goes by, before long the voip line is the main line being used without a review of the fact that there is no 911 service on it. Then at some point the decision is made to ditch the pots line and by then 911 service is nowhere near being on the radar. I have customers with monitored security systems who eliminate their phone lines AND ignore the trouble light on the keypad that appears soon afterwards and then they are mad at me when they discover they are paying for alarm monitoring that can't function! To me this is quite a similar situation to the no 911 situation except the alarm monitoring problem actually created a "trouble light" warning that was STILL ignored.

Off my soap box now...John, I need your soap box to get off of!

Just my view on what can go wrong and WILL go wrong and why some things really shouldn't be allowed. And I didn't even get into the likelihood of people moving their voip service from one location to another and doing nothing to update the 911 address info.

Terry