Mike Johnston wrote:

On 2023-07-26 17:43, Paul Timmins via VoiceOps wrote:

...

I wouldn't be surprised to see carriers dumping these calls via a GSM gateway, this is really common in europe with gray routes. It'd explain why you get weird cellular voicemail, if they sent the number to the cell phone wrong to actually dial out.

I've heard of this! In one instance, the call would come through every one in a dozen or so attempts. And it would often have the wrong calling number. Generally belonging to a cell provider. Audio was not great and there was noticeable latency. The call would only go for a few minutes before dropping.

Going back to the "wrong voicemail system" thing, though...I could easily see a call being placed via a GSM gateway carrying the wrong CLID info (call being sourced from phone # owned by the cell carrier, rather than the original caller). But whenever we would hit these voicemail systems, they would clearly read back to me the number that I *dialed* (e.g., "2125551212 is not available"), demonstrating that -- IF this is a legit voicemail system -- the diversion/RDNIS info is being properly signalled to it. Having RDNIS pass through unmolested over wireless via a gateway seems 1) unlikely (how would that even work? is it possible for a wireless endpoint to signal that??), and 2) the sensation one gets is that the mobile carrier's OWN voicemail system has somehow mistakenly been sent the call, which still doesn't make sense. So your theory about it being a fake termination makes way more sense to me. -- Nathan