Ultimate Caller ID Screeners?

omasse asks: "I'm sick of telemarketing. Really sick. And since I'm in Canada, the new U.S. telemarketing law won't change a thing for me. The only easy solution is a technological one, and it ought to be fully transparent: No phone in my house should ring at all if it's an undesired call, and friends and family should not have to enter a 5-digit code to make them ring. To my knowledge, the only gadget that could do this is a sharp filter based on caller ID that I plug in my main phone drop. But Digitone's Caller ID Screener has been announced some time ago, there are no guarantees they'll meet their fall 2003 deadline, and I would prefer having a few products to chose from. There's been a discussion here once on a DIY home PBX system but that's way, way overkill for me. Could anyone tell me what are the ultimate Caller ID Screeners?"

Comments

Asterisk

[tzanger]

Asterisk can solve that for you. I am playing with it now. It can do different things based on the received CID and even do things like play the "disconnected line" tone sequence before passing the call to you if the CID is unknown.

Just a word of advise: Don't use Quicknet's cards -- the cards work fine but the asterisk developers seem to have something against them, almost forcing you to use Digium's FXO/FXS cards instead. The PhoneJack/LineJacks will work fine for a little while and then you'll get weird problems like oddball rings, CID not being passed through, DTMF not being passed through, all kinds of little issues that you'll have to restart asterisk or reload the modules to fix. The standard answer on #asterisk is "Use Digium cards instead." Right.

Telephone answering machine

[squiggleslash]

CLI (caller line identification, commonly but, as I'll explain, completely inaccurately and deceptively described as "Caller ID") is an answer to the wrong question. You want to know WHO is calling. CLI tells you what the phone number of the person is who's calling, or, for the more expensive variants, what the name of the person associated with the phone is. Neither tells you who. And blocking the number is done for many legitimate reasons, not just by telemarketers.

If you want to know WHO is calling, and be in a position to decide whether to pick up a call on the basis of the person calling, a telephone answering machine is the only option available. Record a message like "Hi, this is X, speak after the tone and if I'm in I'll pick up", and listen when the phone rings.

It is the technological answer. Unfortunately, as it has no LCD screen and doesn't require subscription to an amazing service that beeps FSK tones in between rings, it's also the most crude looking, and thus the easiest to overlook. Unlike CLI, it works, it's 100% foolproof, there is never a false positive or false negative. You're not at the mercy of the networks interconnecting, or the policies of the person whose phone is being used to call you. And, FWIW, you protect the privacy of both you and the caller calling you.