"softfaxmodem", "softmodem"? Windows faxmodem/modem over VoIP/SIP?
 

[OFF TOPIC] Does anyone know any Windows "softfaxmodem"/"softmodem" application that I can put dial-up connections and/or fax over VoIP? In fact I'm interessed in the modem part of it.
Maybe some kind of windows driver that emulates a faxmodem hardware that implements a modem that dials a SIP VoIP service.

Do you know something like that? This will help me a lot.

There is a Fax service in Windows, but not normally installed by default. Then you use this with an ordinary dial-up modem, maybe via a cheap calls provider on an ordinary landline. If you only have broadband, then you might need to buy a dial-up modem for probably under $20. Plug the modem into the other socket on the filter

If it's possible to do this over VoIP, it's something I haven't thought about yet. Maybe it would be as simple as connecting the fax modem to an ATA, but I expect there's a bit more to it than that, and someone else can comment. Or maybe some ATA's can emulate a fax [a total guess, this]? And codecs, etc?

You need your Windows CD. Go to Control Panel > Add or Remove Programs, then click on the left for Add/remove Windows components; tick Fax Services ...

Once it's installed, it's very easy to set up, and faxes can be written separately or from within Office programs, selecting Fax as equivalent to another printer.

Sipgate does it
 

Sipgate has a fax software in Germany. It works like a printer driver. Just install a small program from their website and use it as your printer of choice. They send it then as fax to your receiver.

Sipgate vereinfacht Fax-Versand - Golem.de

Andy, as far as I can remember (I haven't tested it), you should be able to send fax over Voip if you have an ATA that supports the T.38 protocoll.

T.38 seems to be tricky
 

T.38 seems to be tricky. At least Sipgate says:

Does sipgate work for fax numbers?

We have had mixed feedback from users on this one. We currently do not support the T.38 codec which is designed for fax transmittal.

Fax machines are finicky and even an imperceptable delay (using another codec) can result in the fax machine stopping transmission.

Some people report success and others not. We plan to add this codec and offer fax service, but currently it is not integrated.

Thanks all of you. But this is not exactly what I'm looking for.

El_Condor's suggestion is very close in fact. This is fax only and works only with sipgate, but its concept is exactly what I'm look for.

What I'm looking for is an application (windows driver or similar) that can emulate a fax and use SIP VoIP to send it. So, no need for fax card in the PC nor any phone line (pure PSTN or from an ATA). The application would capture the fax in the PC and send it using any VoIP service provider. The provider could be configured in the application just like we configure X-Lite, SJPhone, etc. That's why I'm calling is a "softfax" (just like softphone).

The fax feature is already very nice, but I'd like to also have a modem function. The idea is to have and application that emulates a modem so that I can put dial-up connections only over SIP VoIP, with no modem card nor phone line. This would be the "voip softmodem".

Now you made me courious. What do you need that for? Why modem over VoIP? Sounds weird.

everyone asks that! And not only for me! I've found 1 or 2 posts when googleing for this. In them other people ask just the same for the requesters (yes! there're other people looking for something like that around the world).

Well I can imagine some uses for it, but probably there're others. 3 of them are:
1. I've already seem (and worked for) some companies that the only way to connect their intranet/network is by dialing up. Due to security reasons they do not open their network via internet/VPN.
2. With only one PC and one broadband you can this way open lots of dial-ups. This can be used for simultaneous in/out connections to lots of other PCs/networks.
3. (the one I'm more interested now!) We can make money! :) Here in Brazil there are some free internet service providers that in fact they pay for us just be connected to them (in their business model they make money with the carrier interconnection). And now they pay more than I currently pay to some VSPs to call Brazil! So if I can open 5, 10,....slow dial-ups from only one PC to these ISPs I'll make some money (what they pay less VSP rate that I pay).

Wilson, check this:

Kapanga Softphone | Home

soport t-38 FAX codec

very nice wycodreams!!!

That fax functionality is exactly the way I was missing in voip software till now!!! Let's see if other softphones start implementing it. I'd love to have a freeware for eventual residential use in my notebook. But I'll try this one.

Unfortunately they do not have "modem" so I'll continue my research and I'll thanks any help.