wchan@umd5.umd.edu (Winthrop D Chan) (06/28/90)
I'm trying to find information on the Caller ID that is used in Maryland. I
have seen a few companies offering boxes already, but what I want to do is
make something that will output the information thru an RS-232 compatible
port so I can do security checking on my BBS (also eases validations!). Know
where I could find plans or information on it?
thanks people
Winthrop Chan
=============================================================================
<------- ____ This is how most Computer Science majors look
&&& / \ __ _____, after staying up all night for a few weeks
`-- | o \' ` &&/ and living off of vending machine food.
`| | o },-'
\____( )__/ Winthrop Desmond Chan
,' \' \
/~~~~~~|. | .}~~~\ producer@cscwam.umd.edu producer@eng.umd.edu
,-----( . | .}--.
| . /\___/ wchan@umd5.umd.edu wchan@linus.umd.edu
`----^,\ \ wchan@snoopy.umd.edu wchan@umdd.umd.edu
\_ | ACK!
==============================================================================brian@ucsd.Edu (Brian Kantor) (06/28/90)
In article <6766@umd5.umd.edu> wchan@umd5.umd.edu (Winthrop D Chan) writes: >I'm trying to find information on the Caller ID that is used in Maryland. I >have seen a few companies offering boxes already, but what I want to do is >make something that will output the information thru an RS-232 compatible >port so I can do security checking on my BBS (also eases validations!). Know >where I could find plans or information on it? If caller-id is enabled on your line (i.e., you paid ThePhoneCo to turn it on for you), you'll hear 202 modem tones at 1200 bps between the first and second rings. Methinks you could hack up an old 202 modem to deliver this information to your computer. What's in there is the digits of the caller's phone number and a few flag characters. 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. - Brian
rmf@bpdsun1.uucp (Rob Finley) (06/29/90)
In article <14669@ucsd.Edu> brian@ucsd.Edu (Brian Kantor) writes: >In article <6766@umd5.umd.edu> wchan@umd5.umd.edu (Winthrop D Chan) writes: (stuff deleted) >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? Doesn't seem too easy... Robert.
henry@zoo.toronto.edu (Henry Spencer) (07/01/90)
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
dmt@PacBell.COM (Dave Turner) (07/03/90)
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?
.Doesn't seem too easy...
If you are really concerned about security you should not rely on either
CLID or dialback modems.
Call forwarding can defeat both of these schemes. The really good (bad?)
crackers know how to put call forwarding on an accepted number.
This is getting harder to do but IMHO relying on either will delude you
into thinking that you are safe.
--
Dave Turner 415/823-2001 {att,bellcore,sun,ames,decwrl}!pacbell!dmt