[Asterisk-Users] Sipura 2100 and Asterisk and Fax

[Mark Eissler]

I've just made an interesting observation that I'd like to share with 
you all: the popular Sipura SPA-2100 just doesn't seem to be as great 
as I'd hoped.

I've been trying to get inbound AND outbound faxing working via 
Asterisk and at least one of my termination services: Voicepulse or 
Sixtel. In general, inbound has been working flawlessly but outbound 
has been pretty much broken. Finally, this week I decided to spring for 
a new SIP adapter thinking..."err, it must be my old Azacall 200 that's 
the root of the problem!" Boy was I wrong!

The SPA-2100 got here a couple of days ago but I didn't get a chance to 
fully configure it (aka create a dial plan string for my setup) until 
yesterday. Happily, the first few test faxes to my eFax account went 
out fine even though I routed them through my Sixtel trunk. For the 
most part, when I try to fax out through Sixtel I get a microsecond 
chirp and then silence. At least, yesterday morning everything was 
working fine and I thought..."hey, must be the new adpater!" But no. By 
the afternoon it was back to the chirp and then silence.

I switched to testing inbound via Voicepulse. Now that failed too! This 
had been working time and time again with a hitch with the old adapter? 
What the?????? Must be somewhere in the eight million and growing 
poorly documented config parameters that Sipura gives you. I already 
had all of the Fax stuff off and also turned off the echo stuff. No 
success. I tried changing gain levels...going as low as -12 and as high 
as +12. No success. I tried all of the 600 and 900 impedance settings. 
No success. Finally, I thought to myself...."maybe it's timing? Maybe I 
need to put Asterisk on a faster machine since it's only on an old PPro 
system circa 1998. Hrmmmm. So I installed on an idle PIII that was in 
the rack.

This a.m. I switched over to using the faster Asterisk setup and 
started running the same fax tests (BTW, I'm using free faxback systems 
to test inbound faxes, pretty handy. Go google for them!). Started with 
outbound. Sixtel was still chirping and then dying. So I switched to 
using VPC's megacent outbound for testing. On the old system I always 
had to turn trunking off to fax out successfully over VPC so that is 
the config I went with. Well, it was still no go. I turned all of the 
FAX stuff back on in the Sipura and then I got a fax to go through 
successfully. Hrmmm...

Next, I tried inbound faxing. No success. Didn't matter if the FAX 
stuff was on or off in the Sipura. I googled but could find no help on 
any of this. Most folks seem to still be using POTS for faxing. So I 
poppped out the Sipura and put my Azacall 200 back in. Sent a test fax. 
Perfect! Requested several multi-page faxes from a faxback server and 
they all came in fast and perfect!

The Sipura is now sitting on my desk, ready for an RMA#. Unfortunately, 
the Azacall has a nasty habit of crashing every few days so it's not a 
permanent solution. What I cannot seem to understand is why the old 
Azacall works when the Sipura-2100 (brand new hardware, with the latest 
firmware) just refuses to cooperate in this setup. I figure it must be 
my fax machine and the baud rate.

You see, I have a Brother MFC8300 that's hardwired to 14400bps. I'm 
thinking that the Azacall will support up to 14400bps (like the later 
Cisco ATA-186's will) but the Sipura will only support up to 9600bps. I 
emailed Sipura to find out and all they could manage to tell me was...

===
"You will have better reliability when using 9600bps when using fax.
(along with G711, etc..)

T.38 fax support for SPA-2100 will be available Q2"
===

Gee thanks guys! You could just say "We're too lazy to ask engineering 
what the deal is..." or "We know the real answer but it's a secret..."

So there you go. It's nice that the Sipura has all of the 
configurability that it does but, in the end, if there's no way to know 
how to tweak those parameters or if it still doesn't offer just the 
right switches and knobs then you're pretty much out of luck. Also, if 
the hardware itself doesn't support a certain capability (like being 
able to force a fax machine to retrain to slower speeds) then you're 
also out of luck.

Disclaimer: It is possible that I just have a defective SPA-2100...but 
what are the odds? Besides, my Azacall has supported T.38 for almost a 
year now and the SPA-2100 still doesn't have it (at least, not in the 
current firmware). Not that any of that matters anyhow...

-mark

--
Mark Eissler, mark at mixtur.com
Mixtur Interactive, Inc. - at - http://www.mixtur.com