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Fax over VoIP Killing Me


Absolutely not! you can use real fax machines plain and simple through an ATA , you can add “virtual” iaxmodem or t38modem to virtualize , you can print all incoming faxes to any networked printer routed by DID and send any file (converted by hylafax and it’s extensions) you can use scanners as input devices and there even some hylafax clients that work in winbloze all you need is software that reads and write G4 tif files and that basically is hylafax/libreoffice/imagemagick/ghostscript with all the bells and whistles. Furthermore you have email2fax and fax2email abilities available.

(Steven Sedory) #22

Very cool. Thanks. I definitely need to look further into it then.

(Steven Sedory) #23


We are getting 100% successful faxes now!!

We’re using the same trunks, the same asterisk settings, and the default ATA settings (the Obi 200 you suggested).

So for those of you with fax woes like I was having, and who HAVE to use traditional fax machines, here’s our setup:
-Current version of FreePBX as of this post
-Anveo Direct as VSP
-Outbound Service in Anveo setup with a custom route that only uses ATT, Level3, and LANCK, all T.38 enabled routes
*FYI, for inbound (DID), they say all of their US DID’s are T.38 capable, even the ones we’ve ported. So far, that seems to be true
-T.38 Pass through enabled in FreePBX
-Various ISP’s at various sites (Verizon, TimeWarner, Telepacific, Cox, Internap)
-All sites tied through ipsec VPN from their SonicWalls to a single HA Cisco ASA setup
-On SonicWalls: all features unchecked on VoIP page
-On ASA, inspect sip removed from config
-ATA: Obi 200. Default settings
-Various fax machines used at various sites. All default settings kept, except send/receive speed set to 9600. Haven’t tested faster speeds since the recent successful breakthrough
*Haven’t tested non T.38 routes to see if just ulaw works for fax. Just happy the T.38 ones are working!

That’s it. Thank you again everyone for your input. I hope this post helps others like me that come across this “white whale” as one put it.

(Steven Sedory) #24

*Correction: on the Obi 200, we have Codecs->FAX Event->Enable and Codecs->Codec Settings->T38ECM both enabled. Not sure if this is having a positive affect or not, but don’t have time to (nor do I care to, sorry) test otherwise. I’ve spent 180 hours in the past two weeks on this I think, so…ya.

(John Davies) #26

From what I can see, the Obi 200 has been discontinued in the UK now.

Is this still the preferred method of managing analogue fax machines over IP in 2018?

(Steven Sedory) #27

Yes, at least for us. We’ve been using it for years now.

(John Davies) #28

Are you UK based? They still seem available on Amazon in the US.

Do they depend on Googpe Talk in ant way or is that just a redundant sticker on it?


either an obi100 or a Chinese clone spa3000 from ebay, both under 20 bucks, can register directly with your preferably T38 compliant voip provider should work, no PBX needed.

(John Davies) #30

They all seem to be discountinued / unavailable in the UK. With importing, we’d have issues sourcing the correct electrical plug etc! :frowning:

(Dave Burgess) #31

Faxing over VOIP has had more than one of us put a FAX machine to our head with the hope that it could go off and put us out of our misery.

You could look at the offerings from Synway - they sell a lot of this kind of stuff. I’ve never used the FAX gateway, but I’ve used a lot of the their “Asterisk compatible” hardware and I’ve always been impressed.

(Steven Sedory) #32

US. And no they don’t depend on Google Talk at all, just good ol SIP.

(Steven Sedory) #33

If you want to import a bunch, let me know and maybe I can help. As for power, you can use any $5 AC adapter really (obviously the right size and input/output).

(John Davies) #34

Ah thanks, ordered a HT812 (and purchased a Fax Machine to test too!!!) so will let you know how I get on!

(Peter Arnold Nott) #35

So after all that, do you think the Obi 200 or 100 would be any better than the SPA112 as your ATA? I am having much the same problems with much the same setup. (although I suspect my ISP may be at fault here)


We use FaxStation, works swimmingly! Couldn’t be happier

(Steven Sedory) #37

100% yes.

That said, there are a lot of other factors, but again, yes. Going from the SPAs to the Obis for us brought up our success rate into the 80-90% category, which retries typically take care of.

You also must to as much QoS at your customer site (assuming your server site is good). A lot of our customers use SonicWall, so we use the built in BWM (bandwidth management) to give any traffic going to our servers priority. When we forget to do this, we have lots of fax issues. Clearing the bandwidth path best you can makes sure the very finicky fax data doesn’t get interrupted and thus fail.

(Peter Arnold Nott) #38

Well, I gave the SPA112 another shot and made one change: plugged it directly into the router’s LAN port and not the ethernet switch. Didn’t mess with QOS settings or anything much else. 100% success.


OMG I will never try anything ever again for faxing. The obi200 is amazing!!! Never any
Problems it just works. No special configuration or anything.

Make sure you have a nice clean internet connect with little to no data loss and you will be good to go.


We did well with an Obi for all but one local pharmacy chain. Never connected. Switched to a grandstream ata and everything worked very well. Now I just need to buy a spare.


Amazing how all this works we had tried granstream, Cisco (linksys), and a few others and never had any luck on a consistent basis. And as stated above no more problems now with the obi200