ATA Enquiries, Faxing

[neronut]

Hello all,

A friend, today, was asking me about FPL, he asked if one could attach a fax machine to an ATA and send faxes through it. After some research I found that this is seemingly possible, but the reliability is sketchy. There seems to be some ATAs that support a standard called T.38, such as the Cisco SPA122. It is suppose to be Fax over IP (http://en.wikipedia.org/wiki/T.38). Other devices, such as the PAP2T, say they support Fax passthrough using the G.711 codec. However, reliability is really poor.

Has anyone tried and tested any method of doing this? What is the recommended ATA around here? I learned this evening that you can fax to the voicemail if you have e-mail forwarding turned on, this is quite useful.

If anyone has any insight that would be great,

[Jake]

I have faxed through my PAP2T many times. I did find that if I tried to fax a very complicated paper (such as an image) it failed. but simple typed or handwritten letters went no problem.

[TheHardy]

On the fax machine, turn ON ECM (Error Correcting Mode), and set max baud to 9600. This will MAJORLY improve your chances of successful fax send/receive.

You CAN tinker with a higher baud rate, but your mileage WILL VARY dependent on your ATA and connection speed, latency, jitter etc.

Feel free to ask other questions if you wish!

[neronut]

What is the most common/recommended ATA to get?

[bridonca]

The PAP2 is the most common, Grandstream products I recommend because they handle NAT well. Most ATA devices are more or less the same when it comes to faxing. Other factors weigh in much more like a quality internet connection.

[TheHardy]

Bridonca makes a very valid point -- as long as it is not some "cheap P.O.S." ATA, they all work more or less. A really bad ROUTER and a sketchy internet connection will cause you more headache by a long shot.

By using ECM and setting max tx/rx to 9600, you should be able to overcome minor-to-moderate internet connection fluctuations. If, however, like myself, you are on wireless broadband, you will have a MAJOR uphill battle (one reason why I don't even try an ATA at this time).

Stable internet,
half-decent properly configured fax machine/fax modem,
decent VOIP-friendly router,
decent ATA.

I think that is the correct order to sort things out in!

[Pierre]

DeHardy,
What do you consider decent ATA and VOIP friendly router?

Pierre

[neronut]

I have to say, this forum is awesome. I spend hours last night just reading and learning. It seems the PAT2T is one of the most popular ATAs. It is the one my friend has and it seems to work fairly well, aside from some minor echo issues. The one thing that I have run into and got confused is the name of the Ports on some ATAs. The FXO and FXS ports. What do they mean and which is the most important one? I gather that one is so you can also connect the ATA to a real phone line.

Also, Is there specific codec restrictions to look out for? I read that G.711 allows for Inband faxing but would getting an ATA that supports T.38 help? I guess for normal phoning none of this really matters, as long as the voice makes it through. Some ATAs seem to support STUN which allows them to easily traverse NAT setups, this I perceive as a big plus.

Thanks TheHardy and bridonca for the kind info. I'm trying to get as much information as possible so I can make an informed decision instead of jumping into a world of weird issues. Sorry for the kinda all over the place post.

[TheHardy]

DeHardy,
What do you consider decent ATA and VOIP friendly router?

My setup includes neither of these, so I have no first-hand experience. Many many posts have been made by others with working setups, and most seem partial to whatever they have settled on and is working.

Browsing through some topics, or doing a forum search for a specific ATA and separately router model names will yield you enough information. For the router, brand-name non-bargain bin seems to be a good start ... lots of complaints about the "ValueMart" no-name ones and their less-than-stellar VOIP handling.

[dibsmft]

The PAP2 in various models is very common. It was used by various sip voip services for many years. There are large numbers of PAP2s that were originally locked to a specific provider (I think Vonage was using them for a while). The PAP2 has two FXS (Foreign eXchange Subscriber interface - that connects to a local phone set but not to the PSTN exchange) ports and so can connect to two voip providers at the same time but not to a regular PSTN phone line. Be careful if you buy a cheap PAP2 on line as some are not unlocked, some not properly unlocked and some may be forgeries.

I have a SPA3102 (Linksys) which has only one FXS port but also has an FXO (Foreign eXchange Subscriber interface - to connect to the PSTN exchange phoneline that come into the house) port. This means that SPA3102 can be used to connect both a standard (POTS) PSTN phone line and to a voip service. Incoming calls both from the voip service and the PSTN line ring the same phone connected to the FXS interface and outgoing calls can be made to either voip or PSTN. Calls can be transferred from PSTN to voip and vice versa. The configuration of the 3102 is quite complicated but it is a great little device. The one that I have I used for years but it is not so useful now that I have dropped my PSTN line. I was able to call from the UK using voip (sip) to the ATA and then dial out to number is Canada using PSTN (local calls free . While in Canada I could call the PSTN number of the ATA and then dial out using the voip (sip) line. The 3102 claims to support voip faxing but I have never tested it. From what I know faxing can work but it is better to use (POTS) PSTN if you have it and connect directly to the PSTN line.
I also have a Grandstream GS286, a much simpler device with only one FXS port. It is easy to configure and usually works without much bother although some routers will not play nice with them. I can see why Fongo sell it and it and, like the PAP2, it is used by other voip providers to give their phone service.

Both the PAP2 and the GS286 have been around for a long time now and there are more modern devices available that may be much better but I have not been able to test them.

My main phone is a Yealink T22P three line (SIP) IP phone. I works very well although I have not yet quite figured out some of the settings. The sound quality is amazing. However, because the Fongo service in St. John's NL is quite limited (no local DIDs and poor local free coverage)) I have not connected it to the Fongo service and have to use other providers but I expect that it would work OK with the SIP settings.

[neronut]

Thanks dibsmft for all the Info. I don't have a PSTN line, just my lowly Rogers mobile, so I think I will look for a gateway that is FXO free. I have noticed some of the ATAs have built in routing functionality. I'm assuming that that can be disabled (just like my Bell Modem/Router) and they can be used as if they were just ATAs.