We are running FreePBX 188.8.131.52 and Asterisk 13.30.0 with spandsp 0.0.6, IAXmodem, Hylafax+ 7.0.0 and Faxpro 13.0.44 on CentOS 6. Long time running machine that does well on iaxmodem/hylafax.
The client wants to eliminate POTS and so added fax boards to their Canon Imagerunner MFP. Setup seems easy enough and it will send a few pages fine but when it comes to 30 page documents, it’s rare to get past 20. I’ve checked the bandwidth, latency and jitter which all well within specs required. Things are so bad I installed a SPA112 and while it does better, it trains down to 12000 baud before it reliably sends data. note the canon fax board is pretty bad and trains down to 4800 most of the time.
I’ve changed the error correction from redundant, fec, and adjusted maxdatagrams trying to find a difference and/or sweet spot, no luck. The vendor got a Canon tech online and proceeded to spend 8 hours “testing” faxes in and out. They found the same thing I’ve been telling them all along. The SPA appears to work better than the Canon Fax Board. Big help!
The last test I performed was to connect an SPA112 to the switch the FreePBX box is running on and viola, it ran perfect with 14400 connects and fast page transfers. So it appears the switch network is faulty somewhere, somehow. I don’t manage that part but they tell me they have prioritized for VoIP… it seems pretty obvious to me.
My question is when you have a “perfect” path, latency under 1ms, zero jitter and 124Mb bandwidth (iperf), can the switch interfere that much? There are four hops between the FreePBX and the problem printer.