Modem failed handshake

A few years ago, I tried to connect to Juno or Netzero dialup VIA Google Voice with an OBI 200 device. Essentially, I was trying to connect to the internet through the internet. For reasons I don't know, it didn't work. As you can hear, it fails to handshake. I tried it a few different times with a few different modems. I used to install a fax component of a medical software suite as part of my day job so I had a drawer full of these Startech USB modems at one point that I had pulled out of clients' offices because the software vendor claimed they didn't work with their application. A few different modems, different connection numbers, all the same result. Whats weird is you can fax using google voice and that does do some handshaking but dial up internet doesn't work at all. I assume that's by design. Maybe Google Voice detects certain line noises and intentionally garbles them? Someone much smarter than me probably knows the answer to that. What you hear in this video is exactly what I heard when I tried it.