It's a Quectel EG25-G under the hood:
It's the "global" model, seems to support just about everything carrier/frequency-wise. I'm using it on Verizon in the USA.
115200 by default, manifests as 4 USB serials (and a wwan network interface). I'm running off ttyUSB2 (both ttyUSB2/3 seem to work for smstools).
Here's a few lines from my modem config pertinent to this setup:
I think it might be a Verizon thing, but even when it's registered smstools thinks it's not registered (not smstools fault, the CGREG commands report funky status). Similar issue with the BER.
The more interesting / specific thing - is that Quectel has some kind of "lightweight m2m" protocol/server software etc. I.e. for sensor type networks. This is on by default and you will get occasional "error" messages about this not being set up, not bootstrapping etc. The init line in my config disables the m2m stuff to make the modem much more quiet.
Also (possibly another Verizon thing...) - I had to set:
I could send manually in text mode all day long. PDU mode was giving me fits. Seemed like if I sent to +1AAAPPPSSSS (US/Canada format) the messages went into a blackhole. Setting the national_prefixes got me sending in PDU mode finally.
Not endorsing this product per say, it's just what I bought and had success with. Hopefully this information will help anyone else who might be interested in this or a similar model.