[Asterisk-Users] Application Faxing using SIP

[Philip Edelbrock]

On Feb 18, 2006, at 11:35 AM, J Poz wrote:

> I have a specific business problem that I'm hoping someone has  
> ideas and/or has already worked out a solution.
>
> My application needs to be able to automatically create and issue  
> faxes to many different fax machines. The volume is going to be  
> very high. And it is only about sending faxes and not receiving them.
>
> My application is hosted by an ASP but the Linux (Fedora 2) server  
> is mine (dedicated). So the option of having PSTN lines to do faxes  
> is not an option since I don't own nor can put anything in the data  
> center. I found a SIP/VOIP provider that says they do faxing (and I  
> can connect to them using my own device (meaning asterisk or  
> something else if necessary)). Their requirement for faxing to work  
> on their end is to make sure i send them via their voip service  
> using G.711 codec.
>
> So I've done alot of research on faxing and asterisk and  hylafax  
> but I' m still at a loss. For starters, what is the architecture  
> that I need?
>
> my application --> QUESTION MARK???  ----> VOIP Provider ---> PSTN  
> ---> Fax Machine.
>
> So first question, what should QUESTION MARK be? Is it just  
> Asterisk or a combination of Asterisk and something like hylafax  
> (fax manager). And depending on that answer, what is the  
> configuration that has to be made on it. Even reference to material  
> that explains the configuration would be very helpful to me at this  
> time.
>
> Thanks in advance for the help,


The missing link might be iaxmodem.  It has two interfaces: IAX  
channel for asterisk, and a serial device (in /dev/) which emulates a  
faxmodem.  Then, fax away using hylafax.  I have tried faxing over  
SIP through a provider (broadvoice) to a coworker's fax on the pstn  
this way, and it worked.  I haven't done any testing in volume, though.

So you would have something like:

Doc -> hylafax -> iaxmodem -> * -> voip provider -> pstn -> fax machine


Phil

PS- I suppose if you had multiple SIP accounts with a provider, you  
could create multiple iaxmodems and do things in parallel (assuming  
enough bandwidth and cpu).

PPS- I hope you're not doing fax-spamming with this set up! ;')