I've worked at a telco for 15 years and I can say this problem is not going away anytime soon. The issue is the SS7 network that carriers use inherently trusts calls from long distance trunks without verification... I've analyzed incoming spoofed calls from our STP and they all come from foreign point codes on the SS7 network somewhere else in the world. One potential solution was to block incoming calls from an LD trunk with a local NXX, but since number portability came into play this would also block legitimate calls and couldn't be implemented without also having a whitelist of ported numbers to let through. While you could in theory customize your SS7 STP to do this, the manufactures of that equipment are not very interested in that development work without being paid to do it, and since the FCC/CRTC and other regulatory bodies haven't forced it yet... nobody is voluntarily going to cough up the $$$. This is very similar, in a way, to how email used to be in the 90s.. with open SMTP relays all over the place and anyone could spoof email.. all you need to do to access it is have some sort of digital interface (like a PRI for example) to be able to connect directly and specify (ie spoof) your ANI when placing a call). *--* On Thu, Apr 5, 2018 at 1:44 PM, Dovid Bender <dovid@telecurve.com> wrote:
On Thu, Apr 5, 2018 at 11:12 AM, Brian <brian@nc-ct.net> wrote:
On Thu, 2018-04-05 at 07:55 -0700, Brian Kantor wrote:
So the logical conclusion is that caller ID is useless as an anti-vspam measure and the situation is hopeless, so the only solution is to not personally answer the phone at all -- let voice mail take a message.
Pretty much. We've received calls here with the CID displaying as our own info, and others coming up as a neighbor's number. Some even appear as law enforcement when they're scammers looking for donations to charities that don't exist. I suppose if you're going to commit one crime, go for broke.
This is what I have adopted on my personal landline. With the ringers disconnected. Although I get probably a half-dozen incoming calls a day, perhaps one a week will leave a message. Most of those messages are recorded announcements that started playing even before the voicemail greeting finished.
I've been enjoying quiet on a VoIP line with asterisk. Those who I know/expect/desire calls from I can route them directly to my extension, those others get the IVR. It works parallel to IP routing. I can go a few days without hearing my phone ring yet my logs are filled with spammers/telemarketing calls. Robo-dialers have no clue which extension a human may be at, and I've been doing this for over 15 years with great success. With a digium wildcard, this can work for POTS lines as well.
A simple "Thank you for calling the line of $NAME. To prove you are not a robot press 1". That seems to weed out most of them.
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