I've been playing with voice over IP telephone service for the last couple days. I've had a plain old Magic Jack plugged into a USB port on my desk computer for a while now (2 years maybe). I use it as a spare line, and for the tackle and mold making sideline business. It works pretty decent. Sometimes its a little tinny sounding, but as long as my Internet works it seems to work. Since I upgraded my internet service a while back it has worked much better.
Well, I decided to check out 8x8. They are a service claiming to provide professional grade VOIP services. I know of businesses much larger than mine who are using them. So far I am not impressed. They setup my account wrong, and they couldn't fix it. They had to send me another piece of VOIP equipment to get it to work the way they set it up. Its so I can send faxes using an ordinary analog fax machine over their VOIP service. It doesn't work. (I haven't had an actual fax machine hooked up in years for my business, but I need to test everything.)
They claimed to make some adjustments to their compression codecs, and it supposedly tested in both directions, but I never received a test fax. When I tested further just to make sure hardware was good I plugged both the fax machine and the fax modem into a plain old telephone service (POTS) line. Both pieces of equipment worked fine on POTS. Then on a lark I decided to plug the fax modem into the Magic Jack. I don't figure there was a snowball's chance in heck of that working, but amazingly it did. Then back to the VOIP port from 8x8. No joy. Call goes through, I can hear the fax tones, but it fails every time.
Sadly I must conclude that 8x8 is not quite were they need to be just yet for me to recommend them to my customers. If they want a cheap phone line for occasional use I think a Magic Jack would be a better choice.
I've got three 8x8 VOIP adaptors sitting in my communications room right now. All different models.