I would say no. And faxing just needs to go away. But with those statements out of the way, I'm interested to see if anyone puts forth other MTA / ATAs that just work. We've been using Innomedia devices for a couple of years, and they seem to 'mostly work'. Not perfect by any means, but enough that we don't get a lot of complaints.
Shawn On Fri, Nov 14, 2025 at 2:37 AM Nathan Anderson via VoiceOps < [email protected]> wrote: > (...or, "Any currently-manufactured ATAs with a T.38 gateway > implementation worth a damn?") > > Perhaps some will find this shocking, but for the longest time, we have > been using Motorola VT1005 as our basic, low-port-count TA. We had lucked > into a large source of overstock, still-new-in-box units for cheap some > time ago, but that source is now gone. So we are shopping around for a new > model to take its place. > > Part of the reason we stuck with the venerable Moto for so long was > because our wish list looked like this: > > 1. Reasonable price point > 2. Good performance for price > 3. Solid T.38 implementation > > More to the point, we preferred a single TA that could fulfill all > requirements, rather than having to stock multiple different models (e.g. > one for voice-only, another for customers who actually cared about fax, > etc.). And for the residential/SOHO crowd, it struck me as ridiculous that > some 1-2 port count TAs out there often have MSRPs that are higher than the > routers they're going to be sitting behind (I'm looking at you, Cisco...). > > The thing about the VT1005 is that not only did it have a solid T.38 > gateway feature, but it was hands-down the MOST bullet-proof implementation > I have EVER run across, period. It "just works". Even if I was okay with > stocking a special model for our fax-using customers, and even if price was > no object, I seemingly CANNOT buy another TA with as good an implementation > for love nor money. It was the same story every time: every couple of > years, I'd order another TA model and/or pull out some previous eval units > we'd acquired before & update their firmwares, re-test them, and still run > into tons of issues. So as long as the Moto was still available, I just > kept kicking the can down the road. > > I'm going through that same hell again now, and I have realized over the > last few weeks of opening tickets with hardware vendors & tearing my hair > out that there is a common thread to my failing fax tests. > > 1. Fax TRANSMISSION always works fine (T.38 gatewaying kicks in, the > modems train with each other at 14400bps, pages are sent successfully). > 2. Fax RECEPTION is what breaks down (T.38 gatewaying kicks in, but the > receiving modem -- the one plugged into the TA on our side -- always Fails > To Train at virtually any speed) > 3. ...though #2 is only true with CERTAIN fax modems, while others can > receive faxes with non-Moto ATAs JUST FINE, at speeds up to 14400bps > > The fax modem I usually run my tests through is a cheap little USB-based > hardware modem, but one with only Class 1.0 fax support. It's based on > what seems to be a fairly ubiquitous Conexant chipset, the CX93010. When > paired with Windows Fax & Scan and connected to a Motorola VT1005, > receiving faxes via T.38 works just *fine*. But when paired with literally > any other ATA with T.38 support that I've tried, it will either attempt but > fail to train at 14400bps all the way down to 2400bps, or (with one ATA in > particular) it will finally successfully train and send CFR after training > all the way down to 4800bps, or 2400bps at the worst. > > As far as I can tell, this is not strictly speaking a T.38 problem > per-se. This is an issue seemingly with the DSP on the ATA that's > emulating the remote modem, and there is something about most of these DSP > implementations that at least this particular Conexant-based modem does NOT > like. It can send faxes through these ATAs all day long, but whatever > tones these TAs are generating, the Conexant just isn't having it. > > If I sub in a different fax machine in its place (e.g. big HP > multifunction Laserjet), fax reception (mostly) works great through a lot > of these same ATAs. And similarly, if I just put the Moto back in service > with the Conexant modem, that also works just fine. > > Now, sure, blaming the modem is fair game. And I don't discount the > possibility that there is something that it's doing wrong. The thing > is...the Moto VT just freaking works with it. And the fact that there is > at least one modem model out there -- one with a common enough chipset -- > that virtually all currently-manufactured TA models out there spouting T.38 > support cannot interop with makes me concerned that I'm likely going to run > into more such interop problems in the field with customers' own fax > equipment, after we start deploying & the TA we choose to go with is > suddenly exposed to a much more, erm, diverse crowd of fax machine models. > > What on earth could this modem could be so sensitive to that it doesn't > work with any of the TAs I've tested with it (other than the Moto)...? > > -- > Nathan Anderson > First Step Internet, LLC > [email protected] > > _______________________________________________ > VoiceOps mailing list -- [email protected] > https://lists.voiceops.org/postorius/lists/voiceops.voiceops.org/ > To unsubscribe send an email to [email protected] >
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