blocking scam calls

[#1]

Is there any way to block calls which:

• show a calling number on 1471 (or on your 'phone if you've got one that shows CLI), but

• do NOT show a number ("from an unknown number") on 1572 option 1?

I know some callers - such as hospitals, doctor's surgeries, etc. - withhold their number; that's fair enough, but those show as number withhheld or similar on 1471.

If not, why not? I'd say well over 95% of the scam calls I get match the above.

(I usually press 1 or 2, then when I get a human say "while we're tracing the number, I'd like to ask you some questions about your scam operation". They usually hang up at about "ask".)

[#2]

@G6JPG-0 

I sympathise with what you're trying to achieve, as I used to be plagued by up to FIFTY scam calls every day before I got a CPR Call Blocker (£15 on eBay).

HOWEVER I would question why are you looking for a solution now ? - when you'll be forced to convert your PSTN landline to VoIP probably within 12 months.  Blocking unwanted calls on VoIP is likely to require a completely different fix depending on what phone system you have or intend to get.

FWIW, since I ported my BT landline number to A&A VoIP, the scam calls have dropped to maybe 2 or 3 a week.

I don't understand why it's now less, as the phone number is unchanged, A&A don't appear to block anything on VoIP, and my call blocker is removed (as it worked in-line on the Openreach phone cable).

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[#3]

We have had this issue. I now have a BT Truecall phone which you can either block the calls or send them to answerphone. We have known people "whitelisted" and "anonymous" send to answerphone. Unknown numbers are answered before the phone rings and the caller has to leave their name followed by pressing the # key before they come through. All this is on Andrews and Arnold VOIP 

[#4]

Would that CPR call blocker block the type of call I specified (faked CLI) but let through others (real CLI and withheld CLI)?

Yes, I'm aware of the POTS switchoff, and will be looking into VOIP before too long. But I've actually thought the telecommunications companies between then should have been able to block the type of call I described - fake CLI that 1572 knows is fake - for some years.

Interesting that VoIP (a) cuts down the number of such calls (b) doesn't stop them altogether.

[#5]

I'd previously heard of STIR/SHAKEN but hadn't kept up with progress on implementing it.

However, a quick Google brings up plenty of results (which I've not had time to read).

e.g.

https://commsrisk.com/uk-rejects-stir-shaken-us-plan-to-control-global-caller-id-now-dead/

https://commsrisk.com/yet-more-disinformation-spread-about-stir-shaken-and-the-uk/

[#6]

@G6JPG-0 

CPR call blockers are powered by the PSTN line. This has caused me a problem in the past as if you have a fault this can be detected as an impedance fault, confusing the issue.
BT TrueCall call blocking phones effectively stop spammers’ autodiallers getting through. As a result I have not had one spam call since swapping to one of these at least 5 years ago.

[#7]

Trouble with TrueCall and similar is that they force genuine (but unknown to me) callers to go through a process. Sure, it may stop scam calls, but it might stop some genuine - but time-strapped, or not very techy - callers.

I was wondering if there was a way of stopping specifically, and only, the type of call I described: they do show a CLI, but 1572 knows it is fake. It would need to be something PlusNet implemented, as it needs information only their equipment has. I very much doubt there is, and PN (and others) won't be interested in adding one with the impending demise of the POTS, but just wondered if there was something and I just hadn't found it.

[#8]

@G6JPG-0  here are some ramblings regarding junk calls on VoIP from "RevK" (AKA Adrian Kennard - Director of A&A)

No definitive answer, and the comments below are interesting, but at least someone is thinking about technical solutions.

[#9]

Thanks, interesting. Though nobody there described the sort of call I described (so I've added a post).

[#10]

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@RobPN wrote:

I'd previously heard of STIR/SHAKEN but hadn't kept up with progress on implementing it.

However, a quick Google brings up plenty of results (which I've not had time to read).

e.g.

https://commsrisk.com/uk-rejects-stir-shaken-us-plan-to-control-global-caller-id-now-dead/

https://commsrisk.com/yet-more-disinformation-spread-about-stir-shaken-and-the-uk/

---

That's what I call fighting talk! 😃

AFAIAC, this is all a solution without a problem. Why? Well, keeping it very simple: I don't get scam phone calls.

Why not I do not know. Just another of life's many mysteries...

[#11]

https://commsrisk.com/uk-rejects-stir-shaken-us-plan-to-control-global-caller-id-now-dead/

https://commsrisk.com/yet-more-disinformation-spread-about-stir-shaken-and-the-uk/

That's what I call fighting talk! 

AFAIAC, this is all a solution without a problem. Why? Well, keeping it very simple: I don't get scam phone calls.

Why not I do not know. Just another of life's many mysteries...

Yes, the commsrisk editor does seem to be very against STIR/SHAKEN! (Justifiably so, if it's just a moneymaking scheme the scammers can pay to get round.)

This, and others, is most definitely not a solution without a problem - you must be a member of a very small club that don't get scam calls! Mine varies - I get days with none; I think I've had up to six. I think I've read of people who have had 30 in a day. So it's not a problem for you - but it most definitely is for many of us! (Well, for me, not that much of a problem, more just an irritant. But for some, especially the gullible, it is a problem.)

[#12]

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@G6JPG-0 wrote:

I think I've read of people who have had 30 in a day.

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For me when still on BT landline, 30 unsolicited SPAM calls was a typical day, my worst single day record was 49.

Fortunately my call blocker prevented the phone ringing 99% of the time, but could see the quantity in the daily call log.

.

[#13]

I am using a BT cordless with integrated TrueCall. I've now migrated to VOIP with Andrews and Arnold (highly recommended - landline bill now between £1 and £2 per month) using a Grandstream adapter plugged into the back of the router, and the phone plugged into that. Call blocking works better than when on the copper pair as CLID is much more reliable.

The effectiveness of the call blocker depends on the user: unknown callers or those who withhold their CLID have to give their name, and I have to choose to accept their call. Most scammers just ring off and I never hear the phone ring, but the odd one does try to bluff it "Hi, it's Andrea from the Green Homes Scheme" or "It's Mike" - you've got to be confident and put the phone down. Frequently, of course, the withheld calls says "Doctor" or "Assistant to Mr xxxxx at the hospital", so the good calls do get through and I'm not aware of any genuine caller being turned away.

[#14]

@G6JPG-0 From what I read, 1572 is a system based on "known felons" in some way, I'm guessing from people flagging the numbers as bad is one way. BT could also be clever, and do a check against "non-allocated numbers", and other such things.

Such a system (a) costs & takes time to 'educate'; and (b) is only as good as the data they use... A third party solution would need to do something similar.

(This is very similar to Geolocation of IP addresses: if, for example, a sports site as it thinks you're not in UK, then their geolocation data is bad or not up to date... There's many lists out there, you get what you pay for!)

Do you ever get false positives? Or does your 'whitelist' generally stop that?

[#15]

There are a whole set of Ofcom general conditions which all telecoms providers fail to implement. There is a requirement that the presented CLI should be a valid dialable number. So many of the presented CLI numbers associated with scans are undialavle / invalid.

All calls carry an originating CLI which might not be the Dane as the display (presented) CLI. These ought to raise alarm bells.