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Comment by Overtonwindow | Hacker News Reader

But HOW does it work? It's not clear by the article precisely how this is done. Possibly a triple call system. Three calls to that same number at once, each a millisecond after the other, and when the third hits the voicemail the other two disconnect immediately.

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You really only need a double call. It's quite easy.

I wrote this ages ago http://edoceo.com/exemplar/call-to-voicemail

Oddly, my number gets blown up by these things.

How about call waiting?

It's a far from perfect system. But it hits right like 90+% of the time. YMMV

That's why I was thinking triple call. Only double call would cause call waiting.

I've never gotten them. -shrugs- How strange.

Wasn't thinking of that. I assumed the phone company was complicit and selling this as a service to the telemarketers, but we can't really know if the article avoids any implementation details.

Another way of doing this is looking at LRN database and hitting the voicemail access numbers for the carrier. Often times the pilot number will let you dial a mailbox directly.

LRM database? Could you please elaborate?

LRN database is kind of like the DNS of telephony. Since local numbers can be on any switch, LRN tells everyone which switch manages the number.

See: Location Routing Number https://en.m.wikipedia.org/wiki/Location_Routing_Number

Or bribe the phone company and get direct access to the mail box.

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