It's not hard to whistle a handshake. I've been able to get a modem to connect. Of course actual data is out of the question. It's just loud sharp tones, then just match pitch, the other modem will change a few times and just match it.

It was a silly trick whistling to modems, but these days nobody has one. And I can't say I miss dialup.

On March 10, 2017 5:29:29 AM GMT+08:00, Dave Horsfall <dave@horsfall.org> wrote:
On Thu, 9 Mar 2017, Noel Chiappa wrote:

 Interesting: I've heard this same story, but told about TIPs and the 
 ARPANET. A computer at BBN was set up to regularly dial all the TIP 
 modem lines, to check that they were working. One line was always down, 
 so they listened in, and heard some human say "it's just that pevert 
 with the whistle again".
 
 I wonder which one was the original: anyone know for sure?

Now that takes me back; urban myth, because the calling modem didn't 
squeak until the called modem did.

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