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How Do I Filter Phone Calls on a Land Line?
An anonymous reader asks: "I have a telephone on a plain old land-line, with the option of subscribing to caller-id.
I would like to filter incoming phone calls, diverting them to either the handset or answering machine, based on whether the caller-id matches a list of trusted phone numbers.
Considering that many of today's land-line telephone handsets can display caller-id and store a list of favourite phone numbers, I don't think this is technologically difficult.
AI am not interested in: subscribing to a service provided by my telephone company. I would prefer the filtering occurred on my side of the phone line, or implementing a software solution on my PC. Frankly, that is overkill, and I don't want my PC turned on permanently. I would prefer something like a small, solid-state hardware device. Is there any such thing available?"
http://www.privacycorps.com/products/?id=20
Well the obvious answer (at least to me) is Asterisk. If you don't want a "computer running all the time" build a small box, well.... tuff. Think Mini-ITX. You can put a small HD in in, and put it in a small case. If its only "diverting" calls it doesn't need much power or storage space at all and wouldn't draw much power (also, if you do it right - it could be all passive cooled).
Also - I'm sure no one wants to spend _that much time_ setting up Asterisk, so use TrixBox (Formely Asterisk@Home) instead.
snowulf.com
My AT&T E5965C does exactly that. It's about $120 if you can catch it on sale.
Here it is at Amazon
The Caller-ID information is sent between the first and second ring, so the only way to avoid ringing is to drop the first ring 100% of the time. On the occasions where you do want to talk to someone, the time left to get to the phone is that much shorter.
I have an AASTRA talking Caller-ID box in my house. It does a great job of managing the phone. If the caller has intentionally blocked their Caller-ID information then it automatically answers after one ring and tells them I don't accept blocked calls (which are inevitably from telemarketers) and they should call back with Caller-ID enabled. For the rest, it speaks the phone number so I know who it is before I get to the phone. If it's someone I don't want to talk to then I just let it ring until the answering machine cuts in. It supports blacklisting so that people who annoy me don't even get to leave a message. One interesting feature is that I can record a short audio clip and have it matched to a specific name or number so that it will play that audio clip instead of speaking the number. That's a great help with things like payphones which I will always want to answer no matter what the number is (my telco sends "payphone" as the Caller-ID name).
Years ago (when I still had landlines) I had a box that intercepted all incoming calls without allowing the phones to ring. It delivered a simple message "Please enter your desired extension, or, if you do not know the extension, please dial "O" or wait on the line. Bleep!"
People were given one of several numbers to enter: 472 for family, 333 for work, 505 for businesses, for example.
472 always rang through with a particular ring, 333 rang through with another, 505 it would allow through or not depending on how I set the switch, with yet a third ring style.
Anyone who didn't have a good three digit number went to the answering machine, with no audible ring on any phone.
It was simple and effective, and anyone with the proper code could get through from any touch-tone phone.
People never had any problem with my giving them an extension number, as in "Call me when my car is ready, 206 555 0293, extension 505.)
I don't know if anyone still makes that simple box, but it would be worth checking for...
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Tomas