In general you should not use internet on another computer that using the same internet connection while sending a FAX, but with a router that has QoS capabilities, you should be able to. I have not tried that, but I've just peaked my own curiosity and will try that now to see how well my Cisco handles the network when a FAX is transmitting. No Apple routers, past or present have QoS capabilities.
My Samsung SCX4521F multifunction works for sending, but not receiving. Receiving is difficult and you're better off using a Fax service that converts to PDF if you need to receive a lot. There are lots available and several were posted on this forum, some free. lbmofo posted a good list here
For a dedicated fax machine or a multifunction, look for one that list support for G.711 or T.38 in the specifications. Most manufacturers have their product manuals online in PDF format, and you can look near the end of most manuals and find the specifications. My SCX-4521F only supports the older T.30 specification, but I got lucky because it still works. With one that list support for G.711 or T.38, you might be able to receive faxes as well.
Service: Premier 1/30/2012
BELL Canada Port: 1/30/12 - 2/13/12
TekSavvy via BELL FTTN: 25 Mbps/10 Mbps
Setup: Sagemcom 2864 > Cisco E2000 > Time Capsule v1 > Telo
Handsets: Panasonic KX-TG6655S DECT 6.0
However, faxes are a bit ancient these days.. more and more people are PDF/scanning & digitizing documents and just emailing them for a faster and less hassle send-off (accelerated by mass adoption of tablets & smart phones). Faxes harken back to the days of dial-up modems, which faxes are part of.. Hey, maybe someone wants to try a dial-up 56k modem and dial *99 and see what happens re: bandwidth (16--64KB isn't a good tradeoff for 3-4.5KB), lol.
** It takes a bit for the dtmf of a dialtone to oscillate enough for a fax machine to detect as the ooma chime fades to oscillation of dialtone before dialing.
Also for an Ooma Telo, *96 will work for Faxing, when *98 or *99 doesn't.MLW99 wrote:It was not until I tried *98 (not *99) that my cheapo computer fax modem was able to send faxes. This setup is in an office setting configured as follows: Building Internet modem > building switch > personal switch > Ooma hub > fax modem. I have my fax modem configured as follows: Data Protocol=Disabled. Port speed=9600 baud. Compression=disabled. Flow control=none. I made no QOS setting changes on my Ooma hub. Hope this helps some of you.