Block calls with a twist...

[N7AS]

I get my share of telemarketer calls. I have a User Defined Digit Map (Mblk) to block these calls.

Label:        blk
DigitMap:   (1001|1?6672723381|1?3607194584|6000|0000000000)

In my InboundCallRoute: {(Mblk):}, etc...

I would like to take it one step beyond. What I would like to happen is when a call comes in that's listed in my blk DigitMap, fork the call back the number that called me showing the CID of the offending party. Maybe they will get the idea to stop calling.

[ianobi]

In theory this should work:

InboundCallRoute: {(Mblk):sp1($1>$1)}, etc...

However, I see two possible problems. Firstly, you will be paying for the call back to them. Secondly, you would need to check this box:

Service Providers -> ITSP Profile A -> SIP -> X_SpoofCallerID : checked

For that to work your voip provider on sp1 would have to allow CallerID spoofing.

This is all untested for the moment. Looks like an interesting idea, so I will look deeper into it when I have time.

[QBZappy]

l also tought it was interesting. Chances are that the cid received is more than likely not a real number. If it is a real number the idea of them making harassing calls to themselves is amusing.

[giqcass]

l also tought it was interesting. Chances are that the cid received is more than likely not a real number. If it is a real number the idea of them making harassing calls to themselves is amusing.

Amusing but in all likelihood ineffective.  Legally(in the US) they must show Caller ID of a number they control or of a party they represent.  It's quite common for these companies to use Caller ID for a phone that is never answered. 

For the more responsible companies I see a funny result.
Their robot places a call to you.  A human from their company picks up the phone.  Said human is annoyed by the robot call and they follow the prompts to unsubscribe from future calls. You are off the list.

Funny result 2
Accidental call to you from someones personal cell phone.  Said person is connected to their own Voicemail. 


Many years ago when most of us were still using POTS I paid for selective call forwarding to stop an annoying caller.  I auto forwarded all of her calls to our local laundromat.  She thought the phone system in our town was messed up. lol

[ianobi]

Another easy way to annoy unwanted callers is to send them to free demo or test destinations. Then they pay to call you and it costs you nothing to keep them on the line for a while. This works:

InboundCallRoute: {(Mblk):sp1(wbdemo@conf.zipdx.com)}, etc...

Or send them to an echo test and they can talk to themselves   

[azrobert]

I send unwanted calls to my Callcentric Fax to Email service like this:

{(Mblk):sp2(17771234567@in.callcentric.com;ui=48099999999)}

17771234567 is your Callcentric account.
In Callcentric Call Treatments route CID 4809999999 to FAX.

I read that some robo call systems will auto-remove your number from their list if it senses a FAX tone.
I don't know if this is true.

[ianobi]

I read that some robo call systems will auto-remove your number from their list if it senses a FAX tone.

Seems logical from the robo call system point of view.


I've tested some more and run into a problem which I think has been noted before. This:
sp1($1>$1)} equates to sp1(cid>target)}
$1 is an internal variable containing the value of the caller number of the inbound call.
According to the Obihai documentation sp1($1>$1)} should work. In fact the first $1 does not work and has to be a literal string. The second $1 does work.

Using softphones I got this to work:
sp1('fraudsquad'>$1)}
Normal DECT phones etc won't display "fraudsquad", but maybe a robo call system will record it! Alternatively, you could use a local police or fraud squad number and use this format:
sp1(12345678901>$1)}
12345678901 will be sent as CallerID to the number that made the original call.

Anyhow, there's a few ideas. As QBZappy pointed out, the incoming CallerID may be bogus  as we often see CallerIDs such as "100", "1000" etc.

[QBZappy]

Or send them to an echo test and they can talk to themselves   

I like this one. 

[giqcass]

I send unwanted calls to my Callcentric Fax to Email service like this:

{(Mblk):sp2(17771234567@in.callcentric.com;ui=48099999999)}

17771234567 is your Callcentric account.
In Callcentric Call Treatments route CID 4809999999 to FAX.

I read that some robo call systems will auto-remove your number from their list if it senses a FAX tone.
I don't know if this is true.

I can verify many autodialers have fax detection.  I can't verify they remove the number.  This is a very good idea.  I wonder if a working solution could send a short fax tone before ringing our phone for unknown numbers?

[azrobert]

I can verify many autodialers have fax detection.  I can't verify they remove the number.

Why would they have fax detection if they didn't do anything with it?

If they were smart enough they could start sending ads to you via fax, but I've been doing this for years and it hasn't happened to me.

Edit:

I'll answer my own question.
They wouldn't transfer the call to a rep if they detect a fax.

[N7AS]

I think I'l try some of these...

I may just forward them to 800-356-9919. That may keep them busy.

I remember back in 1985 or so when I lived on Cape Cod, we just got touchtome service (Boston had it years before). We were getting prank calls, so I was tired of answering them. I forwarded all calls to the local PD. A few days passed and a relative dropped by and said that they were trying to reach us and our phone was answered by the PD. I guess I must have forgotten to discontinue the forward. It's a good thing that CallerID wasn't available at that time.

[giqcass]

I can verify many autodialers have fax detection.  I can't verify they remove the number.

Why would they have fax detection if they didn't do anything with it?

If they were smart enough they could start sending ads to you via fax, but I've been doing this for years and it hasn't happened to me.

Edit:

I'll answer my own question.
They wouldn't transfer the call to a rep if they detect a fax.

I investigated a few robocalls services / programs because what you said made sense and I wanted to see if fax detection was a common feature.  Turns out it is.  Many just flag the numbers as fax, busy, disconnected, answering machine, or connected.  Apparently fax detection isn't reliable so they then give the client a list of those numbers and leave it up to the client as to what they want to do with the list.  Some let the client listen in to manually verify the status of the number.  It of course would make sense to remove a fax number from the list as long as you were sure it was a fax.  I did not do an extensive investigation into them all.  I just sampled a few.

I have never received a Robo fax but that was a problem when fax machines were more common.  I haven't heard of anyone complain about one in years.  I have however got a lot of fax machine calls to one of my cellphones but there is no way to know if it's spam or an accident because I couldn't see the faxes on a cell phone.

On a side note the FCC says you shouldn't talk to someone that robo calls you.  Which is obvious but they also say don't unsubscribe either.  They say when you unsubscribe the company that robocalled you knows it's a live number with a real person answering.  Then they resell your number to other robocallers.

[Ostracus]

I think I'l try some of these...

I may just forward them to 800-356-9919. That may keep them busy.

I remember back in 1985 or so when I lived on Cape Cod, we just got touchtome service (Boston had it years before).

Wow! That is old school.

[Robert.Thompson]

http://www.jeffdoubleyou.com/bin/view/VoIP/TestPhoneNumbers

[gderf]

Forward them to Lenny.

sip:lenny@sip.itslenny.com:5060

[Lavarock7]

I have had problems with Lenny (they also instituted a preamble that kinda negates it sounding like Lenny just answers the phone).

I have used 2 recordings, one is:

Due to the hurricane in the area you are calling, your call cannot be completed at this time.

http://www.phworld.org/sounds/modern/att/

There were a number od recordings Allison made for PBX's, numerous ones, but I can't find then now. Allison Smith did real recordings so her voice is familiar to people. When you slide in a humorous one like this, http://www.digium.com/sites/digium/files/content/resources/pleasehold.wav you really get peoples attention.

Some of her humerous ones are:

"Thank you for calling. Self destruct has been initiated will occur in thirty seconds. If you believe you have reached this destination in error please enter the twelve digit abort code now or hang up and seek shelter immediately."

"It's not you, it's me. Let's find an agent."

[giqcass]

http://www.digium.com/sites/digium/files/content/resources/pleasehold.wav

I love this one.  Then send the call to MOH lol!

[KAura]

A long time ago I wanted to block callers so I wrote a program...
I called my fax machine and recorded it trying to answer the call and saved it to a wave file.  I then played that wave file to all of the callers I wanted to block according to missing caller id information, a telemarketer list, etc.  I died laughing when some 'smart' people [that I had previously blocked] called back and actually tried to send me a fax.  Of course there was no way that they could possibly connect.

[giqcass]

We should set up a honeypot and test some of these deterrents.