The death of voiceband modem communications is slowly but surely happening. I started Project Fax in recognition of this, as a way to remember one of the technologies, but sadly from the few faxes I have received, it seems I might be too late.
Regardless, we exist in an awkward period where there are still users of voiceband modem technologies, and somehow in an IP-centric world, we have to maintain backwards compatibility in a way that is somewhat reliable (enough) and hopefully not too costly.
To that end, fax diagnostic services are important for us to verify the proper functioning of our equipment. In Australia, Telstra operates FOLDS and FOLDS-B which provide technical information about the quality of your fax transmission. The only other commonly cited phone numbers are those in the USA, so I sought to try them out before they eventually go extinct.
As I reside in Australia, and I’m not travelling to the US anytime soon, I had to devise connectivity to the US to both fax the service and obtain the reply fax without having a physical land-line in my possession.
As a result, VoIP technology (i.e. not optimal for fax) was leveraged to perform this. All the test fax numbers are toll free and calls can be placed to these numbers through free online SIP toll free termination. The one I chose to use was Alcazar Networks, as they forward the CID as set and claim T.38 support. Note that calls in pass-through mode use G.711u in the USA as compared to G.711a in Australia, and setting the incorrect mode can result in call quality degradation due to transcoding.
The incoming line was provided by Callcentric, using their “free” inbound US DID program – the same number that is used for the US incoming line for Project Fax. Incoming calls are auto-answered by Digium Free Fax for Asterisk running on my FreePBX server, converted to PDF and e-mailed to me. This is a “virtual” fax machine to receive the faxes.
While I could place outgoing fax calls using the FreePBX server, I found the process to be problematic and unreliable. I tried using WinFax PRO under Windows 2000 Professional in a VM with a USB-to-Serial adapter with my Netcomm modem of choice, but it wasn’t operating properly today for some silly reason, so I resorted to an old Dell Latitude C600 laptop with Windows 2000 Professional and WinFax PRO using its internal mini-PCI 3com modem. In essence, a real physical computer to do the faxing. This was connected to the Grandstream HT802 ATA to convert the call to IP, sending it directly to Alcazar Networks by configuring it for “no-registration” operation.
To ensure the fax would be sent back to the correct number, the DID was programmed to the incoming Callcentric number, and the CSID was set in the US “domestic” 10-digit format – i.e. xxx-xxx-xxxx without the hyphens.
Hewlett Packard (1-888-HP-FAX-ME)
The most often cited number is this one, and you receive a return fax if your fax to them completes successfully. No technical information is provided about your call.
The next most often cited one is Brother’s test line. Again, no technical information is provided.
This number is operated by Canon, and I only recently discovered it. This one seems to send you back a fax that they have scanned rather crudely, but there is no technical information provided either.
I have managed to successfully, and without cost to myself, test and demonstrate the three toll-free test fax numbers in the US that I am aware of. The reply fax was successfully received and documented. Unfortunately, unlike the Australian services, none of the US services above provide any technical information or guidance as to the quality of your fax transmission – only providing an indication that your fax is successful with a reply even if the call was marginal.