<div class="gmail_quote">Thank you very much for your answer Steve.</div><div class="gmail_quote"><br></div><div class="gmail_quote">Would be FS + mod_spandsp good both for incoming and outgoing faxeds?</div><div class="gmail_quote">
<br></div><div class="gmail_quote">What could be achieved to avoid media timing issues you told? </div><div class="gmail_quote"><br></div><div class="gmail_quote">Regards</div><div class="gmail_quote"><br></div><div class="gmail_quote">
<br></div><div class="gmail_quote">2011/5/9 Steve Underwood <span dir="ltr"><<a href="mailto:steveu@coppice.org">steveu@coppice.org</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On 05/09/2011 01:16 AM, Juan Antonio Ibaņez Santorum wrote:<br>
> How much reliable FS + mod_spandsp is compared to other solutions<br>
> (open source or not)?<br>
</div>The open source options are:<br>
<br>
Asterisk + spandsp<br>
Asterisk + Hylafax + iaxmodem + spandsp<br>
Freeswitch<br>
<br>
These are all tested and proven to give well below 1% failures, even<br>
with quite a lot of concurrent FAX channels in use, if things are set up<br>
well. They can give you bad failure rates if things are not set up well.<br>
I believe that right now you will have less trouble achieving a reliable<br>
setup with Freeswitch. Going forward, most of my effort goes into making<br>
the Freeswitch option the most thoroughly implemented one.<br>
<br>
The main commercial option is:<br>
<br>
Asterisk + Digium's commercial FAX<br>
<br>
Of course, there are numerous other fully commercial FAXing options<br>
which could be used in conjunction with things like Asterisk or Freeswitch<br>
<br>
The Digium FAX module is based on the well known Commetrex FAX engine,<br>
which is widely deployed, and should be capable of solid results.<br>
However, the module is more than just the core FAX engine, and some<br>
people do have serious trouble with the module. I have helped moved<br>
people off this, and onto Asterisk + spandsp, to improve their<br>
reliability. In a couple of those cases people were getting quite a lot<br>
of pages cut short when receiving FAXes with T.38, even though a<br>
wireshark log showed a perfect exchange, from which I could correctly<br>
decode these FAXes. The module was not reporting any errors. In a couple<br>
of cases strange machines were sending weird things the Digium FAX<br>
didn't cope with very well. I worked with these people to make sure<br>
spandsp did handle the weird stuff well, and we ended up with a more<br>
usable solution. These people told me that when they complained to<br>
Digium they got little help. The best was an offer of a refund. Paying<br>
to get some support didn't seem to work out too well for these people,<br>
but I guess if the support you are looking for is mostly in getting<br>
things configured and working on day one you might get value for money.<br>
<br>
All these solutions require reliable signaling and reliable media<br>
timing, and many people have setups which cannot achieve that. Most<br>
people don't understand how things work, and will claim a solution<br>
doesn't function for spurious reasons. For example, a number of people<br>
say the spandsp module for Asterisk doesn't work, because they keep<br>
getting a 488 response. That response has nothing to do with the FAX<br>
engine. It is a negotiation error that occurs outside the FAX engine. If<br>
they fixed their configuration the error would go away. However, many<br>
just move on, having "proven" to themselves the solution doesn't work.<br><br></blockquote></div>