This number called me four times yesterday, but no message was left. The message I received when I called this number back was: "The number you have dialed is unallocated." I have never heard of this message. It sounds like there is no such number, so how did someone call four times from that number? It is irritating.

The "The number you have dialed is unallocated." message was either generated by their VOIP provider or by their phone system.  All of this stuff is very configurable - the old rules of Ma Bell being the only source of system messages are no longer in effect.  

Caller ID info is not very meaningful, and there is no real connection between phone numbers (DIDs), which are used for inbound calls, and the ability to place outbound calls.  Likewise, system messages are whatever the DID holder wants them to be, so not terribly meaningful either.

Hope this helps shed a little light on the "mysterious" shenanigans engaged in by tele-nuisances.

Here are some details on this particular nuisance:

Inetmedia, LLC
(303) 785-5014     3677 S Huron St Ste 105, Englewood, CO 80110-3466

fight voip with voip filtering

caller ID comes up as "INETMEDIA, LLC"
has called me 10 times so far today