Mike Johnston wrote:

I serve a rural area. I do the technical "make it work" stuff. I'm generally only involved in the business dealings insofar as determining technical incompatibilities (draw 7 red lines, all perpendicular, some with green ink and some with transparent). That said, please forgive any errors in what I say, and feel free to correct me.

This was all super interesting and helpful; thanks!

I try to find numbers that go to IVRs, fax numbers, automated airport weather numbers, etc. Anything that doesn't involve bothering a human over and over. It has to be with the same OCN though, and generally needs to be in the same NPA-NXX too.

Yes; correct. In this particular instance, a county library system that we service a lot of branches for was having trouble calling a particular branch that lies outside of our service area. I knew that branch's operating hours, and they have an answering machine, so I would run my tests while they were closed.

These are generally fake voicemails. Just a recording of some voicemail intro, to make you think you hit a voicemail box. The call hasn't actually been mis-routed. It hasn't been "routed" anywhere, other than to an audio file.

I suspected it was either this, or it was hitting a genuine voicemail system that was perhaps misconfigured and accepting calls for any RDNIS / voicemail boxes it received. Though I guess if I'd thought about it for 2 seconds, if it had actually been AT&T's voicemail system, then it would have told me that the destination mailbox in question had not yet been initialized / set up.

Are you sure it actually rang a line at some business? Or maybe it was, again, just an audio file? Some wav file on a server at Bob's Shady Long Distance Shack?

[...]

I would argue it is fraud. But again, prove to me they are actually "routing" to any number, and not some audio file.

Fair point. I don't actually know. -- Nathan