I believe that you are wrong. We are talking about a dial-up modem not a DSL router. Dial-up modems doesn't auto-negotiate/connect. They let the stack do it. Unless he has a special kind of modem that i'm not aware of..
Well, believe what you like, but, I have 25 years experience with modems; my first one had an acoustic coupler! I have never in my life heard of a modem that requires the use of a TCP/IP stack, unless there is some new M$-compliant modem that I'm not aware of. All dial-up modems, and even the ones without dialing capability "auto-negotiate/connect" all on their own.
Proof: I take my serial dumb-terminal, and plug it into my Hayes compatible modem. I type "+++ATDT" and then the phone number of some other modem, and, then I turn the serial dumb-terminal off, so, the modem is acting all on its own. (Provided, the modem is configured to ignore the DSR line). The modem will dial the number, negotiate a connection with the remote modem, and go online. Simple as that. It's online, and will stay that way until the line gets disconnected (or one of them is set to time out and hang up).
So, lets say that MiamiDX causes the modem to dial, and never acknowledges that the modem is online, and also never tells the modem to hang up. The modem is online and connected, and the TCP/IP stack is not.
It is actually very possible to have misconfigured MiamiDX to cause this situation.
