Date: Mon, 7 Sep 1992 12:14:08 GMT
From: cc_paul@rcvie.co.at (Wolf Paul)
Newsgroups: comp.dcom.telecom
Subject: Re: V.25bis, or: Are CCITT and PTTs Totally Bonkers?
Reply-To: cc_paul@rcvie.co.at (Wolf N. Paul)
Organization: Alcatel Austria - Elin Research Center, Vienna
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 690, Message 8 of 10

In article <telecom12.680.5@eecs.nwu.edu> mcb@presto.ig.com (Michael
C. Berch) writes:

Commenting on V.25bis Delayed & Forbidden Numbers lists, and the term
"stay on this list forever" used in the Multitech Modem manual:

> OK, I can see that a PTT might want to have some reasonable
> regulations that restrict automatic redialing by modems and similar
> devices, to prevent older switch equipment from being overloaded.  But
> ... a Forbidden Numbers list?  With numbers that stay on it FOREVER??
> Have these people totally taken leave of their senses?  If I dial up
> my local BBS in Zurich, and the system is down, and the modem doesn't
> answer four times, I am Forbidden from ever trying it again?

> I assume that either I am not reading something right, or that V.25bis
> is optional/voluntary, or outdated, or something, but I really can't
> imagine what reasonable thoughts were occurring in the heads of the
> people that thought up this scheme.  Does anyone have any ideas about
> what CCITT was trying to accomplish here?

Well, the purpose of this feature is not so much to prevent line
overloading, but rather to prevent harrassment of voice phone
customers.

Thus, in my experience, also with Multitech modems, "failure to
connect" means the phone is answered, BUT NOT BY A MODEM. If there is
no answer at all, the feature does not kick in. If the phone is
answered but there is no modem tone it does. Imagine a slightly
mistyped phone number in a UUCP L-sys entry which gets called every
fifteen minutes ...

"Forever" is also relative ... the list is cleared by turning the
modem off and on again. The point is, it requires manual intervention.
Otherwise some people would put the software command to clear the
"forbidden list" into their modem reset sequence at the beginning of
each dial command ...

I agree however that the wording in the Multitech manual is unclear
and rather drastic.


Wolf N. Paul, Computer Center    wnp@rcvie.co.at
Alcatel-Elin Research Center     +43-1-391621-122 (w)
Ruthnergasse 1-7                 +43-1-391452 (fax)
ELIN RESEARCH   A-1210 Vienna-Austria/Europe   +43-1-2246913 (h)


[Moderator's Note: A sad thing happened here several years ago when a
FIDO site kept trying to connect with another FIDO site several times
nightly for about *two weeks* ... only to reach the voice number of a
70-year old woman in error. IBT tracked the fellow down and handed him
a seven word ultimatum: "The BBS goes offline today. Permanently. Period."
Either that or he could risk having the Illinois Commerce Commission
order IBT to disconnect his service, since the lady had already filed
a complaint and made a big stink with all concerned.  He turned off
the BBS for several months until things quieted down.  Then there was
the First National Bank of Chicago's infamous FAX machine which kept
calling a family in Germany at 3 AM German time for awhile. Bundespost
got AT&T involved; AT&T backtracked it to IBT and the bank. IBT gave
the bank some good old-fashioned hell in return. FNB/Chicago is so
incompetent -- remember, that's the bank that the $5 per hour wire
transfer clerk ripped off for twenty million dollars! -- that a month
later when their long distance bill showed several dozen one-minute
calls to Germany, some clerk in the bank's telecom department had the
nerve to call IBT to get the charges removed 'due to some billing
error by AT&T ...'  Then a telco supervisor really blasted them!  PAT]