How to block ghost calls

[cgrainger]

Hey All,

I am one of the admins who look after the 3CX/PBX server in my office. Basically for a while now we have been receiving a ton of "Ghost Calls" Looking into the issue i was able to find the root cause and take action. We have blocked a ton of numbers, IP addresses, and blocked IP Calls in the firmware on the physical handset. This has appeared to cut down the number of calls on an hourly basis (by 90%) however we still get two or three a day.

Apart from the changes implemented already, is there any other setting or service that can be used to stop any ghost/robocalls.

<b>Note:</b> That all the calls that have been blocked were suspected of being a sip scanner (100,1000,10000 etc) however the numbers that keep calling appear to be physical numbers from a mobile or landline service.

<i>Cal</i>

 

[leejor]

Are these Direct SIP calls to specific phones, or something passing through 3CX? If direct, what make of sets are involved? There have been a number of posts over years on some solutions available, but set specific.

 

[cobaltit]

So a current and configured to spec 3CX system with supported phones should be receiving zero ghost calls. Now you may be getting spam/spoofed calls to your actual DIDs, but you should be receiving zero ghost calls with no configuration needed.

 

[cgrainger]

hmmm kk i assume there would be no way to physically check for a human and disconnect before ringing then

 

[cgrainger]

Are these Direct SIP calls to specific phones, or something passing through 3CX? If direct, what make of sets are involved? There have been a number of posts over years on some solutions available, but set specific.

they are passing through our 3CX

 

[cobaltit]

hmmm kk i assume there would be no way to physically check for a human and disconnect before ringing then

There's lots of ways, but you have to balance the benefit of screening the calls vs the drawback of annoying legitimate callers. The easiest would be to route calls to an IVR first. Can be something simple like 'Thank you for calling XYZ company. Press 1 to continue'. Other options are something like Nomorobo which we offer on our SIP trunks. Ultimately though the spoofing has emboldened this spammers so until SHAKEN/STIR is rolled out it's going to be an issue

 

[leejor]

If these calls are passing through 3CX (coming in on a trunk), then they are not technically a :"ghost call". They would be considered Spam calls which many of us have to deal with often. Unless they happen to re-use the same number(s), and can be blocked that way, which most spam callers don't, then you would have to resort to the IVR "human test", as mentioned above. Some providers now offer a similar service, although perhaps, not for businesses..

 

[cgrainger]

awesome,

Thanks for the info everyone