Caller ID integration UK

[StigOfTheDump]

We seem to be plagued with callers offering double glazing, cavity wall and PPI recovery services. We are registered with TPS but I assume most of these calls come from abroad now with VOIP.

I have just registered with BTs free 'Privacy at Home' scheme which includes free 'Caller Display'. I see there are standalone caller ID boxes on ebay for not much money.

Has anyone ever integrated a Picaxe to one of these to be able to reject with-held numbers without paying BTs £4.30/month charge? I could then turn off the ringer and use a sounder on the Picaxe to alert for real calls. The only downside would be the scammers might waste a lot of their valuable time waiting for me to answer the phone when it isn't even ringing.

I know BT are very touchy about connecting equipment to their lines. I wondered whether some sort of optical recognition could be devised to read the diplayed number even if it only could recognise a certain character or even pixel(s) in particular places.

Has anyone ever tried it?

 

[techElder]

Would you only let it ring on an acceptable list of numbers? How large would that set be? How would you edit the list?

PS. We now have calls (in the USA) from the same company phone numbers from all over the US. They spoof the caller ID regularly and don't monitor the "no call" list here.

 

[inglewoodpete]

Maybe it's time to step up(?) to IP telephony. A miriad of options, all available for a fee!

 

[g6ejd]

I think that decoding the caller-id data (a short burst of Frequency Shift Keying (FSK) ~ 128-bit length) just after the ring would be relatively easy, but not for a PICAXE as I don't recall seeing any FSK demodulation capability. This could be done in the low-level machine code though, so getting a little more complicated.

Unless the service provider sends the data down the line of course decoding will; never be epossible, luckily (unlike most providers) BT is sending the data for free.

To my mind, it would be cheaper, quicker and easier to buy a phone (only a very few don't have the caller-id capability) and use that rather than paying BT £52/year for a display box, especially when £52 would get someone a top end Panasonic for that money, which matches caller to address book and can reject classes of call for example VOIP /out of area/international which are frequent called-id displays for marketing calls.

TPS takes about 3-months to kick in.

 

[StigOfTheDump]

To start with I would only bar with-held numbers. If they don't want me to know who they are, I don't want to speak to them. If you 1471 these nuiscance callers, they seem to come from with-held numbers.

Internet telephony is not a viable option here. We live in the sticks and can only manage 500k broadband as we are too far from the exchange.

Since my first post I have got 3 turns of the incoming telephone cable wrapped round the scope probe and can see the ring tone coming in, but out of phase with the actual phone ringing. An email has just informed me that my 'Caller Display' will be active from Monday so I will see what other information I can syphon off. Some form of pick-up on the cable could be a better option than the optical way.

Wouldn't it be absolutely brilliant if BT sent nuiscance callers numbers with an additional code to disable number recognition devices.

 

[Buzby]

Hi Stig,

I tried this years ago.

There was no PICAXE involved, I had a '56K voice modem' and some PC software that came with it.
The software recognised the CLID and displayed it onscreen. The audio was routed to the PC's speaker and mic.
This particular software came with examples of how to integrate it with VB or C, but I didn't do much with it.

Hacking the caller display box will be tricky, but the modem option is still a viable option, and nowadays these modems are cheap as chips on e**y.

It would be reasonably easy to replace the PC with any RS232 capable device, such as a PICAXE.
This could then drive a sounder with different tunes for different incoming numbers.
( I am fairly sure the PICAXE won't be able to handle the voice data. )

The beauty of the modem option is that it is all BT safe, as you only connect to the modem, which is already BT approved.

There is a good write up about how CLID works here : http://www.ainslie.org.uk/callerid/cli_faq.htm

Sounds like an interesting project !.

Cheers,

Buzby

 

[StigOfTheDump]

Thanks Buzby

That's very encouraging.

Apart from your name obviously, when I'm trying to hack a telephone system. Takes me back to the old illegal CB days in the 70s.

10:10

 

[srnet]

To start with I would only bar with-held numbers. If they don't want me to know who they are, I don't want to speak to them.

My experience has been that a reasonable percentage of people who really do have a genuine reason to speak to me and where I do want to speak to them, use witheld numbers.

 

[Dippy]

When I get home from work I typically have 4 or 5 'witheld' , 'unknown' or 'internationals' in the phone log.
If I take the day off work (e.g. today) I often answer calls without looking at the screen.
Most are surveys or double-glazing etc. (Most don't seem to comply with TPS in UK but there are probably lots of wriggleouts).
The internationals are usually surveys by people with unintelligible accents (factual, not racist) and faint voices.
So, my experience is exactly the opposite of srnets - sadly.


I started a design a few years back and here is some info that may help your project.
Firstly, in UK at least, the ID data should come through before the ring signal so you could use a 'relay' to prevent your phone ringing - and maybe divert the call onto your own 'entertaining' or 'utterly offensive' (just kidding) response routine.

Check out Consumer Microcircuits Limited , Zarlink and similar.
Useful info can be obtained from SIN 227 from BT (for UK).
As to whether these are out of date now (or even still exist) is up to your careful research.
Great care is required with your circuit design and component choice.
My project was not in PICAXE BASIC so I can't provide code.

Obviously any cockups resulting from tampering with phone lines are on your own head...so I don't want any moans aimed at me if you screw up.

Personally, I think it should be illegal for Companies and Corporations to withold their numbers.

 

[inglewoodpete]

If you use a message bank or similar answering machine, legitimate callers with ID blocking can leave a message. I found that sales and cold callers don't leave a message.

In Australia, the "Do Not Call" register is policed pretty strongly and I rarely get a call from these people these days. I have CID display, too, for the few that try it on.

 

[hippy]

I recently had the joys of someone trying to scam me for some accident that I'd apparently had in the last three years. Always happy to waste their time and money I simply played along. Unfortunately they did not seem to have any script ready for "yes, what information would you like me to supply you with" and eventually hung up on me !

Worst scam ever ! I'm mystified how it was meant to have worked.

 

[techElder]

That was really my point in a previous post. Here in the USA the phone spammers found out real quick that few would answer if the display showed "BLOCKED" or "WITHHELD", so many of them have gone to the method of routing their calls through numbers from all around the country. The caller ID simply displays something similar to "Seattle, WA" and a real number. I guess they do it through VOIP. These are truly spammers. If you settle on one method of blocking them, they will just switch methods.

Illegality is not the issue here. It is illegal. Enforcement is the issue. As you well know, government does not respond fairly.

... Personally, I think it should be illegal for Companies and Corporations to withold their numbers.

 

[Dippy]

I assume it's not illegal in UK. I honestly don't know. Get Eclectic on the case.
On the odd occasion that my Bank phones me the number is always withheld.
I must check as I'm bursting to have a moan about something!
It's raining so I'm bored


I must admit I've never seen anything like your phone scammers/spammers do. Cunning and annoying. And shows up a weakness in the system.


Though , in some cases, maybe the annoyed recipient can help the authorities.
A million people complaining about something dodgy can sometimes get balls rolling.
That's probably what started the (somewhat patchy and feeble) TPS and MPS in UK.
But, like you say, legislation and enforcement are two different animals.

Sometimes even Governments can be moved by sheer numbers and the Press (and, in UK, media programmes such as "Watchdog" and "You and Yours" and other current affairs output). Votes and image.

 

[Buzby]

.... Apart from your name obviously, ....

My name comes from the nickname I got for being on the phone to my girlfriend all the time, not because I worked for BT !.

Getting back to the real issue, your idea of tapping off via a magnetic loop is fine, it doesn't affect the phone line at all.

However, you will need some analogue circuitry to amplify and 'clean up' the signal before it gets to the PICAXE.
Then you will need to spend time hand-decoding the pulses, and then write clever code to do the job in the PICAXE.

With the cost of a 56K modem being less than the price of a Skinny Latte, I know which route I'd take.

( I just saw on e**y that the Xircom PCMCIA modem I paid £300 for all those years ago now doesn't sell at £2.99 ! )

Cheers,

Buzby

 

[Dippy]

Mmm... have you spent less time on the phone since March?
I notice the share price has dropped.

 

[Buzby]

It was a long time ago !.

I married the girlfriend, and it's our 25th anniversary this year.

 

[inglewoodpete]

It was a long time ago !.

I married the girlfriend, and it's our 25th anniversary this year.

"I married her: it was the only way I could keep my 'phone bills down"

 

[papaof2]

The only downside would be the scammers might waste a lot of their valuable time waiting for me to answer the phone when it isn't even ringing.

In the US, the hucksters only let it ring 3 or 4 times before hanging up. I have voicemail set to pick up on the 4th ring and almost never get a "live" caller - although I do get some automated call devices, those that startplaying their spiel as soon as audio is detected.

I also have a (Phillips?) voice caller ID box that gives the calling number and can have a brief message recorded for those you want to speak to (family, friends, boss, etc). It's much simpler to listen for "Sam", "Sam's work", or "Sam's cell" than to remember 3 numbers for each person.