It would not only be a form of fraud, but sounds be a violation of the Rural Call Completion rules (specifically 47 CFR 64.2119(a)). I would recommend you make a complaint to the FCC and categorize them at Rural Call Completion issues. Provide as much info as you can on carrier names, dates and times of the calls. The FCC staff do contact carriers and intermediate providers to track down RCC problems. I worked with one rural provider in the US on an issue related to rural call completion, and our complaints were getting callbacks to help us troubleshoot from Comcast, Verizon and AT&T at different points in the troubleshooting. The FCC requires all the intermediate providers to retain records of call routing attempts in a readily-accessed format for six months. https://www.ecfr.gov/current/title-47/section-64.2103 There are minimum standards of quality for carriers related to the successful delivery and routing of calls. https://www.ecfr.gov/current/title-47/section-64.2119 (I'm an engineer, not a lawyer, and this is technical advice, not legal advice.) Mark R Lindsey | +1-229-316-0013 | mrl at ecg.co | Schedule a Meeting <https://ecg.co/lindsey/schedule> | Newsletter <https://www.linkedin.com/newsletters/mark-lindsey-voice-7021614437413330944/>

On Jul 26, 2023, at 09:28, Nathan Anderson via VoiceOps <voiceops at voiceops.org> wrote:

...by which I mean, we send a call to a term provider via SIP, who then *seems* to terminate the call to the wrong callee entirely.

What the heck actually causes this?

Whenever I have experienced it, it inevitably involves a rural carrier of some kind, one that likely charges a lot to accept traffic. Over the course of a few days, we just went through twelve rounds of having a wholesale term provider blacklist various carriers from their LCRs for calls headed to this particular exchange, before the problem stopped happening. "Is it working yet?" "Nope." "How about now?" "Still nope." And it's random and sporadic enough that I have to place a lot of test calls (as well as continue to field feedback from our end-users) before I can be sure that the problem is actually fixed. It's aggravating...

It doesn't seem to be the final destination carrier that's screwing up the call routing after having received the call: I can call the same number over and over again through a "reputable" carrier, or via my personal cell (but I repeat myself), and get connected to the right destination every time. Based on my experiences, I highly doubt the misdirected calls are even getting as far as the CO's switch for that exchange.

So I have to hypothesize that some sketch carrier getting is picked from an LCR table, one who just doesn't like sending the call to a rural carrier who either charges that much, or that they suspect is engaging in fraud. But...WHY *misroute* it? I'd rather you just reject the call if you don't want to carry it.

The misrouted calls in this latest case more often than not seemed to be hitting a foreign voicemail system that sounded an awful lot like AT&T Mobility's default voicemail greeting. But we have definitely had calls just end up ringing the absolute wrong phone...in one case a few months back, I tried ringing the public library branch in this one rural town, and ended up getting the answering machine for some random business (...and also the call quality was *abysmal* on top of that). (Never did manage to figure out where that business whose answering machine I got was actually located. It was a generic-enough name for a business in their industry, but what I can tell you is that there was no business by that name in the rate centers covered by that rural carrier. And also that my CDRs back up the fact that I did *not* mis-dial that call.)

About the only theory I can come up with that makes a lick of sense is that these cut-rate carriers in these LCRs decide to throw to a rando number if they get asked to term to a high-cost exchange, so that they can record a call completion and charge the caller for it anyway. Which would be a form of fraud itself, if that's actually happening.

I suppose there could be a leg of the call that is being signalled non-digitally (so, not SS7, not SIP, ...), and something is getting either mis-transmitted or mis-interpreted. But if they were doing something like (e.g.) in-band DTMF over a crap connection to an old switch somewhere, I would expect dropped digits, and thus not enough to construct a viable & valid destination number out of.

-- Nathan

_______________________________________________ VoiceOps mailing list VoiceOps at voiceops.org https://puck.nether.net/mailman/listinfo/voiceops

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. On 2023-07-26 08:28, Nathan Anderson via VoiceOps wrote:

...by which I mean, we send a call to a term provider via SIP, who then *seems* to terminate the call to the wrong callee entirely.

What the heck actually causes this?

A long distance carrier, generally an intermediate one, being shady. Here at my workplace, we call that carrier something like, "Bob's Shady Long Distance Shack." Bob probably charges 1 cent per minutes, or less, as a flat rate. When he gets calls for cellphones or urban areas, the calls might cost him 0.1 of a cent per minute, and Bob is doing good. But when Bob gets calls to rural areas that cost more than one 1 cent per minute, he doesn't like that. It cuts into his profits. So he does shady stuff.

Whenever I have experienced it, it inevitably involves a rural carrier of some kind, one that likely charges a lot to accept traffic.

"Charges a lot to accept traffic," makes it seem like a troll under a bridge, making up whatever rate they want to pass. My understanding is that these rates were set by a process that involved distance, to help cover fixed infrastructure costs. Thus, rural areas cost more to call.

Over the course of a few days, we just went through twelve rounds of having a wholesale term provider blacklist various carriers from their LCRs for calls headed to this particular exchange, before the problem stopped happening.

It seems that Bob's Shady Long Distance Shack is popular. Either that, or there are multiple intermediate carriers in play. For example, if you route a call to carrier A, they route the call to carrier I, who routes the call to carrier BOB. If you try a different carrier, they might also send the call to carrier I, who will still send the call to carrier BOB.

"Is it working yet?" "Nope." "How about now?" "Still nope." And it's random and sporadic enough that I have to place a lot of test calls (as well as continue to field feedback from our end-users) before I can be sure that the problem is actually fixed. It's aggravating...

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. We have a test number with an announcement in every one of our assigned blocks. It is the last number, such as 9999 or 2999. If you want to test, look up OCN 1505 and OCN 194F. If you would like an exhaustive list of those numbers, email me off list.

It doesn't seem to be the final destination carrier that's screwing up the call routing after having received the call: I can call the same number over and over again through a "reputable" carrier, or via my personal cell (but I repeat myself), and get connected to the right destination every time. Based on my experiences, I highly doubt the misdirected calls are even getting as far as the CO's switch for that exchange.

Correct. If I had received the call, I would have routed the call. I can't imagine why any rural telephone company would route calls to fake voicemails, fake announcements, static noises, etc. I've even worked with my upstream on some calls, and they don't receive them either. If they received the call, they would have sent it to me.

So I have to hypothesize that some sketch carrier getting is picked from an LCR table, one who just doesn't like sending the call to a rural carrier who either charges that much

The FCC has a page about this, by the way. https://www.fcc.gov/general/rural-call-completion-problems-long-distance-or-... When working with your carriers, using the exact phrase "Rural Call Completion" should help. And please, file reports with the FCC! There isn't much the rural telephone companies can do at the receiving end, since we don't know about the calls we don't receive.

or that they suspect is engaging in fraud.

It's possible you are referring to this: https://en.wikipedia.org/wiki/Traffic_pumping Is that a thing that some rural telcos are still doing?

But...WHY *misroute* it? I'd rather you just reject the call if you don't want to carry it.

I also want to know! Don't offer to route calls you can't complete, right?

The misrouted calls in this latest case more often than not seemed to be hitting a foreign voicemail system that sounded an awful lot like AT&T Mobility's default voicemail greeting.

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.

But we have definitely had calls just end up ringing the absolute wrong phone...in one case a few months back, I tried ringing the public library branch in this one rural town, and ended up getting the answering machine for some random business

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?

(...and also the call quality was *abysmal* on top of that). (Never did manage to figure out where that business whose answering machine I got was actually located. It was a generic-enough name for a business in their industry, but what I can tell you is that there was no business by that name in the rate centers covered by that rural carrier.

Yup, that's common. More stuff to fake a person out. Make you think it must be a problem at the far end.

And also that my CDRs back up the fact that I did *not* mis-dial that call.)

Bob's Shady Long Distance Shack still wants to collect his money on that call, though.

About the only theory I can come up with that makes a lick of sense is that these cut-rate carriers in these LCRs decide to throw to a rando number if they get asked to term to a high-cost exchange, so that they can record a call completion and charge the caller for it anyway. Which would be a form of fraud itself, if that's actually happening.

I would argue it is fraud. But again, prove to me they are actually "routing" to any number, and not some audio file. I am currently struggling with one where an alarm monitoring company serving an alarm system at a facility can not call a Sheriff's office.. The alarm system can call the monitoring company, but the monitoring company can not call into our rural area. I have no way of troubleshooting this issue at the receiving end. I have no idea who the call center is using for long distance. I can only assume the monitoring company is actively working with their long distance carrier. I liken it to ordering something online, where the shipping method is labeled as "Best Method Ground" or something generic. And the online store dumps all their boxed up items off at a shipping center who does the actual shipping out. Some packages go out UPS, some FedEx, some USPS, some DHL, and so on. Sometimes those carriers outsource to another carrier, who might only get it as far as your regional USPS office. Then your regional USPS office hires a truck to bring it to your local USPS office. A mail carrier brings it to your office building. A guy in your office brings it to your department. Your cubicle-mate brings it to your desk.