Hey guys,
We're trying to save some money by ditching our land lines (we have two phone numbers!) and moving to VOIP.
I decided to go with OBIHAI because of how highly configurable the devices are, and the fact you can use the free Google Voice service.
I've already moved one of our two lines over to Google Voice (via the 'move to cellphone temporarily, then port to Google' trick), and it's been up and running for a few months now.
My mom's FAX machine is on the second line. This was the hard part, because Google Voice does not do T38 or similar. I had played around with it, because some users in Reddit's /r/voip had reported that some fax machines actually do cooperate with Google Voice if you set them to the lower-speed mode.
Well, regardless, that didn't work. We tried several times, and we were generally able to GET faxes, but not send them.
So I just signed up for PhonePower over the holiday break. I picked them because they're cheap ($5 a month for OBIHAI users) and explicitly support faxing and the T38 codec.
Well, much to my dismay, it's doing the exact same thing as it did before on Google Voice. I sent a test fax from my RingCentral number at work (I don't have a real fax machine to test with, just the "e-fax" service.)
The message came in on the first try, so I was feeling pretty optimistic.
So I had my mom try to send it back to me to see if it would go through. It didn't. I received a partial transmission - and the Brother fax machine would automatically retry as it knew the transmission failed... I got 3 or 4 failed faxes. Each one was a bit different, one was only about 1/20 of the page, one was maybe 1/4 of the page, but the point is that it didn't get anywhere close to sending the whole transmission.
I called PhonePower and asked them what they would suggest, and the guy I talked to said (much like I had heard from Reddit) that the fax machine needs to be in low-speed mode (which Brother calls "basic" - 9600bps with error correction disabled) and that you shouldn't be using error correction. He confirmed that they support T38, and said usually if you set it up through OBITalk it should "just work" - exactly like I was expecting.
So I had my mom change it from standard (~14000bps) to basic mode and try again. The same thing happened. I'd get a tiny sliver with the page header and not much more - it's like the connection gets terminated in the middle or something.
Looking in both my local config settings and the OBITalk Expert Settings, I can see codec profile B has T38Enable checked, and T38ECM unchecked - which is correct per PhonePower's tech support. I confirmed that "SP2" is using codec profile B, which it is.
So I'm really out of ideas here. Since I like troubleshooting things myself before asking for help, I tried enabling the "FAX Event" mode in codec profile B, but that didn't seem to affect things one way or the other.
Surely somebody has used a fax machine with PhonePower using an OBI - that's one of the things the company advertises as being supported! Does anyone have any other advice? I'd hate to have to get a new fax machine, because the one we have was hard to come by - it's got a "smart answering" mode where it will wait for our answering machine to pick up the call, then if it hears the fax beeps it'll take over and receive the transmission. Most cheaper machines, it either automatically picks up all calls or you have to manually pick it up to start receiving.
One other thing I wasn't sure about, the default settings for T38 have the "Fax Passthrough Codec" as G711U. G711A is the other option you can select. Additionally, G726 Bitpacking is set to big endian, with little endian being the other option.
The guy at PhonePower did not know what those settings did, as they make it pretty clear they can't support OBI devices (it's why they sell their own, and why the OBI plan is cheaper since you don't get hardware support) - hence why I'm posting here!
Fast replies would be appreciated since I'll need to use the 30-day money back guarantee if we can't get this thing working before the end of January. I paid for a whole year upfront - but if my mom can't receive faxes, what are we paying for?
Edit: I guess I should have specified - I bought an OBI202 because it's got the two phone ports (one per line). Our house has two actual, separate lines, it's not just two phone numbers.
So I have it configured where Phone 1 is using SP1 (Google Voice) and Phone 2 is using SP2 (PhonePower). Phone 1 defaults to SP2 for emergency calls, since PhonePower supports 911 and GV doesn't. Take a look here:
The other question I'm sure I'll be asked is in regards to how I power an entire house's phone line from an OBI - thankfully most of the work was done already! For the past 3-4 years, we've been using our ISP's bundled telephone service instead of an analog one (it was a tad bit cheaper but not much). When the cable guy came to set it up back then, he took care of all the wiring, voltage adapters and all that fun stuff to make it work with VOIP. So basically, I just unplugged the phone cable from the back of the modem and into the OBI instead. Assuming the OBI202 outputs the same type of signal that a telephone modem would (and I'm pretty sure the answer is yes), the rest just works. Both lines (GV and PhonePower) will ring on every phone in the house, it's pretty neat.
