Phones - Caller i/d (a bit OT)

[Andrew Gabriel]

They are passed as a flag, and also in the text field of the callerid data. (Not all callerid devices will display the text field, as BT abandoned using it for peoples' names very early on after a trial in one area.)

There are a number of occasions when BT proves additional info in the text field of the callerid data, as I described earlier. (Actually, I missed one out which I've seen, RINGBACK, which also mirrors the ringback call type in the callerid data.)

That's how the BELL system works. BT sends the data before the first ring, preceded by a line reversal. There's also an off-hook signalling method which is used during call waiting, but that requires that the phone indicates it can take the data when off-hook, or it's not sent.

[Brian Sharrock]

Thanks ! So the string is not originating _in_ my library of stored numbers. 'They' transmit strings as well as numbers for CLID.

[Peter Parry]

You are absolutely right. I meant to mention both but got distracted!

Has that ever been implemented? I was under the impression it wasn't used (or it may just be that not many phones can use it).

[Andrew Gabriel]

It is implemented, but I don't think many phones support it. Separate caller display units can't use it, as it is necessary to momentarily cut off the audio path whilst receiving the callerid data, so the feature needs to be integrated in the phone.

[Adrian C]

I must be plagued with different operators than you ;-)

I get a few of these a month, and previously when I have said "hello" an operator has either responded back, or the line drops immediately. Now I say nothing and wait for someone to make the first move. They never do, silence and the line drops ;-)

-- Adrian C

[James Hawkins]

Does anyone know specifically why they don't do this, or don't at least present the country of origin? I would like to ignore the International ones as they are 99% marketing but I have relatives abroad so I can't. BT surely knows the country of origin and probably even the originating phone number in most instances these days.

If someone were to say that there is money in it for operators like BT to ensure you do answer calls and they know all too well that if presented with the country of origin perhaps 80% of those calls would go unanswered from then on, I would not be at all surprised.

[Guy King]

The message from James Hawkins contains these words:

I would imagine that the originating country uses a different system to ours and that the data isn't present or not in a form that BT can be arsed to decode.

[tim(yet another new home)]

not just BT.

I was working in Asia this year and incoming calls from home were displayed as something like 000694000 which bore no resemblence to the real number.

If I missed a call, I had no idea who to call back.

tim

[Adrian Simpson]

In article , James Hawkins writes

Not all "international" calls are really "international". I recently had an "international" call from a company doing a survey, they claimed to be in Lowestoft, I didn't ask them why they appeared to be calling from overseas. On another occasion when I got one, it was from a mate of mine in Cheshire. Knowing he gets about a bit, I asked him where he was calling from, to which he replied "home". Turns out that he had some cheap calls deal with Wanadoo, so they were probably being routed via France.

Adrian

[Peter Parry]

The calls route through a number of countries and the routes change by the minute depending upon bulk traffic costs. The originating country isn't always easy to work out (as CLI information isn't universal).

[Andrew Gabriel]

If I redirect my landline to my mobile, international callerid is displayed, so BT clearly have it and pass it on in the redirection. It usually looks reasonable (it's always correct in the case of callers I know), but occasionally it's clearly garbage.

There may be problems with some of the exchanges not being able to handle international numbers in the callerid software (e.g. more digits). That's the only reason I can imagine BT mark all international calls with UNAVAILABLE when they clearly do have the number to hand.

[Ian Stirling]

AIUI, it's pretty easy to forge the number that's typically sent in the US, for example.

[Adrian C]

Calls made to my BT-line from Skype also show as 'International'

-- Adrian C

[judith lea]

They display all numbers of the person calling, unless that person has deliberately withheld their number. I have had a lot of silent calls to my office but not to my home which is ex-directory, they do indeed display the number calling, this information is also logged, so that information can be used later if these are malicious calls and are admissable in litigation.

[Peter Parry]

I get a number of calls from one overseas number direct to a mobile and they variously show up as the number itself, a meaningless number, international or withheld. How well the originating CLI survives seems to depend entirely upon the route taken which these days of purchase of bulk data can bear no relationship to the physical localities.

I vaguely remember seeing a BT document about this some years ago and believe they made the decision to show "International" as it was at least consistent rather than varying the display of information depending upon the time of day and direction the wind was blowing from! (I could equally be entirely wrong as it was a decade ago).

[Derek Gledard]

It works for me.

I think many dect clid phones do it.

It's only a "Dit"

DG

[Aidan Karley]

We get an irregular alternation of "Out of area", "Withheld", and "Unavailable" when the mother-in-law phones from Belgorod (Russia-Ukraine border). Can't see any pattern to why it gives each message.

[PeTe33]

I have just been tinkering around with VOIP at home. Using a company called voipcheap.com to dial out gives 5 hours/week worth of free calls to loads of countries including UK, and UK mobiles for a paltry 4p/minute (0.06 Euro)

Only slight (or significant) downside is Caller ID shows up as "out of area" because it is going via US presumably.

As long as your friends know you'll be "out of area" I guess it's not a problem.

:¬)