[asterisk-users] Digium Fax Driver

[Tzafrir Cohen]

On Sun, Jun 07, 2009 at 10:15:42PM -0500, Tilghman Lesher wrote:

> IAXmodem is a completely different ball of wax, and I think you would agree
> that if the builtin FAX support in spandsp provided excellent support, there
> never would have been a reason for IAXmodem to be developed.

Reminder: SpanDSP was originally GPL. Steve Underwood wrote rx_fax.c and
tx_fax.c that were basically thin wrappers for it. They were not so easy
to use because:

1. They were out of tree to start with (which made life much more
   difficult. Certainly before 1.4).
2. The API and ABI of SpanDSP kept changing, and you had to know the
   right version to use.
3. They weren't much well-behaving Asterisk apps (e.g.: used their own
   log file) and generally got very little maintinance (also due to
   (2)).

There was much resistance to even adding those apps to asterisk-addons.
I guess that merely (2) would have made them a support burden. IAXmodem
avoided the issue by using its own copy of SpanDSP.

With the release of SpanDSP 0.0.5 things started changing:

A. The license was changed to LGPL for the library itself. This allowed
   using it is Asterisk and FreeSwitch.
B. Finally some attention to stable API and ABI.

An app_fax.c was written initially in Asterisk-Addons only about at this
stage, with an eye on T.38 integration. Shortly after it was moved to
Asterisk itself. 

This was when Asterisk 1.6.0 was at release stages, IIRC. At the time
IAXmodem was well-mature. So what you wrote should probably be rephrased
as:

 If the builtin FAX support in *Asterisk* provided excellent support, there
 never would have been a reason for IAXmodem to be developed.

(But still see Lee Howard's comment in the other followup).

-- 
               Tzafrir Cohen
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