[Freeswitch-users] Fwd: Major deployment of outbound FAX on latest version of Freeswitch question

[Steve Underwood]

On 05/12/2011 05:21 PM, Juan Antonio Ibañez Santorum wrote:
> Hello Steve!
>
>    I would like to ask you one question about fax system. You told 
> that using FS+mod_spandsp could be gotten successful faxing rates over 
> 99%. Looking at your experience, is 99% nearer to 100% or to 99%? 
> Which errors do you find usually on that 1%?
>
You can run tests all day in a lab without failure. The real test is how 
well things work against a wide diversity of machines in the real world. 
This http://www.soft-switch.org/spandsp-soft-fax-performance.html says 
something about our testing, and what is achievable. Its quite a lot of 
work to get real reliability numbers. You get a lot of call failures on 
a typical public FAX server due to things like wrong numbers, voice 
calls into a FAX port, people purposefully dropping half completed FAX 
calls, and buggy FAX machines doing weird things. Don't ignore the last 
one. There are famous make machines with serious bugs. You need to 
manually check the failed calls one by one to get real reliability 
figures. In the end there are always a few calls where you are never 
sure who's fault the failure is. All I can say with hand on heart is the 
number of unexplainable failures is well below 1%

Regards,
Steve