Ooma Forums

I know this has probably been covered a 100 times, but I am up against the wall at this point while trying to send faxes with ooma. I have gone through 2 fax machines in hope that maybe the problem was something related to the fax. I have tried every combination of ECM, and Baud rates available on the fax.

Current configuration:

Fax connected directly to ooma Hub with no splitters into the phone port.
Fax is Dialing with *99, pause, then phone number. You get stutter tone after the *99, and hear the handshake.
ECM = OFF
Baud Rate = 9600

When using this config, it has failed 100% of the time.

Fax machines attempted are HP J3680, and Brother FAX-565 and both fail the same way.

Does anyone else have any other advise, since I know this works for some of the users here.

-Brandon

bcreekmore wrote: Current configuration:

Fax connected directly to ooma Hub with no splitters into the phone port.
Fax is Dialing with *99, pause, then phone number. You get stutter tone after the *99, and hear the handshake.
ECM = OFF
Baud Rate = 9600

When using this config, it has failed 100% of the time.

Does anyone else have any other advise, since I know this works for some of the users here.

Hi, I just installed my Ooma hub yesterday, and had the exact same issue as you've described. Even with *99, and hearing the handshake, only about 1 out of 5 - 10 faxes went through. And it turns out that at the receiving end, the fax that I thought went through showed up as a receiving error.

I didn't have any issues receiving faxes at my Ooma hub-connected Brother MFC-7820N that were sent using a fax service such as FaxZero. I tried all sorts of settings, and have finally found one change that makes my fax work with 100% reliability for both sending and receiving.

On the Ooma hub, I've disabled QoS for the upstream internet stream. The default is 384 kbps, and before disabing it, I tried values that ranged from 50% to approximately 80% of my upstream bandwidth as estimated by http://whichvoip.com or http://speedtest.net. Nothing worked, until I went the other way, and disabled it. I've sent faxes to a variety of machines with no problem.

I've also moved my Ooma hub to be after my router, rather than before it - although this change doesn't appear to affect faxing.

Hope this helps you.
DG

Wow, that is interesting. I just tested your suggestion, and it worked! 10 page fax went right through with no problem. This looks like a bug, not a codec issue, etc? Can someone from ooma chime in on this one. Possible theories, as to why turning off upstream QoS allows faxes to work, and maybe a fix for this?

bcreekmore wrote:Wow, that is interesting. I just tested your suggestion, and it worked! 10 page fax went right through with no problem. This looks like a bug, not a codec issue, etc? Can someone from ooma chime in on this one. Possible theories, as to why turning off upstream QoS allows faxes to work, and maybe a fix for this?

It puzzles me as well - and I would prefer to know why this works.

It would appear that either I don't understand QoS very well (which is possible), or there is something strange about the QoS implementation in the Ooma hub. Logically, it would seem that a QoS that is about 80% of the available upstream bandwidth should be optimal (at least as described in an Ooma document on QoS).

Right now, my Ooma hub is behind my router - a Netgear WRN834B - which has an "intelligent" QoS implementation, and things still work, as long as QoS is disabled on the Ooma device. This leads me to speculate that there may be a bug in the Ooma hub QoS implementation.

DG

THANKS DG, it works for me, surprisely, after disabled QoS for the upstream internet stream....

daet wrote:

bcreekmore wrote: Current configuration:

Fax connected directly to ooma Hub with no splitters into the phone port.
Fax is Dialing with *99, pause, then phone number. You get stutter tone after the *99, and hear the handshake.
ECM = OFF
Baud Rate = 9600

When using this config, it has failed 100% of the time.

Does anyone else have any other advise, since I know this works for some of the users here.

Hi, I just installed my Ooma hub yesterday, and had the exact same issue as you've described. Even with *99, and hearing the handshake, only about 1 out of 5 - 10 faxes went through. And it turns out that at the receiving end, the fax that I thought went through showed up as a receiving error.

I didn't have any issues receiving faxes at my Ooma hub-connected Brother MFC-7820N that were sent using a fax service such as FaxZero. I tried all sorts of settings, and have finally found one change that makes my fax work with 100% reliability for both sending and receiving.

On the Ooma hub, I've disabled QoS for the upstream internet stream. The default is 384 kbps, and before disabing it, I tried values that ranged from 50% to approximately 80% of my upstream bandwidth as estimated by http://whichvoip.com or http://speedtest.net. Nothing worked, until I went the other way, and disabled it. I've sent faxes to a variety of machines with no problem.

I've also moved my Ooma hub to be after my router, rather than before it - although this change doesn't appear to affect faxing.

Hope this helps you.
DG

I'd like to know what is going on as well. Our "fax guy" is out this week, but I'll have him investigate when he is back.

Dennis P wrote:I'd like to know what is going on as well. Our "fax guy" is out this week, but I'll have him investigate when he is back.

I have a theory - either the restrictions imposed by QoS, or the time taken to calculate bandwidth introduces small but variable amounts of latency - this doesn't matter for voice transmission, but affects fax transmission - which is very timing dependent.

DG

I toyed around with the QoS settings but they turned out not to make a difference. What did work for me was reducing the number of rings required for the fax machine to pick up to 2. Actually, I think all that matters is that the fax machine picks up before the ooma voicemail does. As such, I ended up increasing the number of rings [ooma.com/lounge->preferences->voicemail] of to 5 or 6 [higher than the fax machine]

I've actually had more luck faxing with Ooma than my previous primary VOIP provider (or the one before that, too). I'm using a Lexmark all-in-one. My hub is behind my router (but the PAP2 I used with the previous provider was, too). Faxes typically don't work well with any VOIP service; I was pleasantly surprised once I had set up the Ooma hub. I don't like leaving my fax machine on all the time, plus, I've been burned in the past with multiple spam faxes that eat through paper and ink/toner. So for incoming faxes, I use a free fax service that delivers the fax to me via email (K7). In the past, when I had more faxes coming in on a regular basis, I subscribed to a paid service that did the same thing.

after trying fax for few days mine finally worked with ooma, i have brother MFC 7820N, i used *99 pause and and the number, it worked, status report says it was sent, the cool thing is i could use any pc in house to send fax using MFC 8720N. i have used splitter at hub to fax and other to multi set panasonic phone. the setting on fax is set to 9600 and compatibility to basic (this is very important) otherwise it might not work. my ooma hub is after router (apple airport extreme dual band)