Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Wanted: caller ID specs/plans/etc...
Message-ID: <1990Jun30.235612.4448@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <6766@umd5.umd.edu> <14669@ucsd.Edu> <1990Jun29.130847.25026@bpdsun1.uucp>
Date: Sat, 30 Jun 90 23:56:12 GMT

In article <1990Jun29.130847.25026@bpdsun1.uucp> rmf@bpdsun1.UUCP (Rob Finley) writes:
>>I'm waiting until Telebit or one of the other advanced modem
>>manufacturers offers this in their standard product - i.e., the modem
>>loads a string register with the contents of the CLID on an incoming
>>call.
>
>If this were to take place, it would work even better than dialback security 
>for sensitive computer services.  Is there a way to defeat this?  

None I can think of... but the price you will pay (aside from the extra
on the phone bill for caller ID, since contrary to popular myth, it's not
free) is some degree of denial of service.  For one thing, you will be
unreachable for anyone working from an old exchange which doesn't support
caller ID.  Those are increasingly uncommon in metropolitan areas, but
are not at all rare out in the boondocks.  Similar problems may arise for
calls from hotel rooms and international calls.  And something that will
be a problem even within cities is that you get the phone number only
once and there isn't even parity on it, so garbled numbers will be a
non-trivial nuisance if your line or exchange is a bit noisy.
-- 
"Either NFS must be scrapped or NFS    | Henry Spencer at U of Toronto Zoology
must be changed."  -John K. Ousterhout |  henry@zoo.toronto.edu   utzoo!henry