Setting up a Grandstream HT802 for fax service. Without changing any other settings, if I set toronto6 as the SIP server, it registers, but if I set fax2, it doesn’t.
I can watch the Syslog from the Grandstream, it seems that it connects to both servers, but for the fax server it never gets any further.
The fax DID is configured to route incoming faxes to the correct subaccount. Because there’s no setting for it, I’m guessing that the fax DID doesn’t need to agree with that set in the ATA as is the practice with the voice numbers.
NAT is appropriate, enabled, and configured per wiki. TLS is not enabled (yet).
I was using fax2 'cause that’s what it was originally set to.
I substituted fax1.voip.ms and it registers.
I can make voice calls via the fax machine handset. Faxes get as far as the modem tones (that takes me back) but the actual fax send never starts, and the fax machine hangs up and waits to redial.
You get the fax to have its initial handshake, but faxes are quite sensitive to many things such as timing, jitter, echo cancelation, packet loss, codec missmatches, etc. It might need finer adjustment in the FXS port settings, including but not limited to a more basic codec like PCMU, the fax mode (T.38, or others, try this one first), reception and transmission speed, etc. And of course, make sure you do not have SIP ALG enabled on your router. (And use TLS connection if this is not already the case to reduce network issues.)
But frankly, I would take the fax and send it to your local recycling facility, and use a virtual fax (or FoIP). This is more reliable, PDF no paper, email to fax, fax to email, etc. I think in many cases, it could be easier. It depends of the usage.
We are the local recycling facility! I’d love to send the thing to the grinder. It’s a medical application, though, so I have to make something fax-y work. I’ve done it before, it’s always a new adventure.
Thanks for the analysis, some of the things I’ve tried and some not. I did set T.38 first thing. I have toyed with ALG before, but it’s not present now. I left TLS off for simplicity, will try enabling it and see.
Also, let me correct myself on my previous post: SIP ALG should be deactivated (a router setting).
Using TLS might solve communication stability issues (i.e. things related to network issues).
Yeah, it makes so many years I did not setup a fax that my only other tips would be to seach with an AI for troubleshooting. It can save you time as it can parse many websites much faster.
This is more reliable, PDF no paper, email to fax, fax to email, etc. I think in many cases, it could be easier. It depends of the usage.