[Asterisk-Users] IAXmodem fax polling

[Lee Howard]

Matt Riddell wrote:

>Colin Anderson wrote:
>  
>
>>>Steve Underwood also informed me about chan_fax
>>>(http://www.sofaswitch.org/chan_fax/), I'll have a look.
>>>      
>>>
>>This looks awesome please report back to the list on this if you get it
>>working correctly. 
>>    
>>
>
>What's the idea of this?  How does it relate to spandsp, t38 patches,
>iaxmodem, hylafax?
>

It relates because chan_fax uses the spandsp library and is similar to 
iaxmodem in that the "modem" part behind both chan_fax and iaxmodem is 
almost exactly the same stuff.  It relates to HylaFAX because HylaFAX 
interacts with fax modems in order to send and receive faxes.

It has practically nothing to do with T.38.

IAXmodem is nice in that it's small, and can be installed on virtually 
any IAX2-supporting system.  The downside to IAXmodem, however, is just 
that... IAX2 isn't exactly an ideal IPC medium... pushing all data 
through the network driver isn't exactly necessary for the purpose of 
getting bits from the PBX to the soft-modem DSP.

chan_fax removes that less-ideal stuff from that scenario by putting the 
modem directly into the channel driver.  The expense of this, however, 
is that it isn't as simple an approach.

Lee.