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- Path: sparky!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!news.acns.nwu.edu!telecom-request
- From: nagle@netcom.com (John Nagle)
- Newsgroups: comp.dcom.telecom
- Subject: Re: V.25bis, or: Are CCITT and PTTs Totally Bonkers?
- Message-ID: <telecom12.693.3@eecs.nwu.edu>
- Date: 7 Sep 92 19:12:28 GMT
- Sender: Telecom@eecs.nwu.edu
- Organization: Netcom - Online Communication Services (408 241-9760 guest)
- Lines: 35
- Approved: Telecom@eecs.nwu.edu
- X-Submissions-To: telecom@eecs.nwu.edu
- X-Administrivia-To: telecom-request@eecs.nwu.edu
- X-Telecom-Digest: Volume 12, Issue 693, Message 3 of 9
-
- Toby Nixon <tnixon@hayes.com> writes:
-
- > In article <telecom12.680.5@eecs.nwu.edu>, mcb@presto.ig.com
- > (Michael C. Berch) writes:
-
- >> 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?
-
- If it works reasonably, this is a useful feature. If you call a
- number, and it is busy, some countries require that you not call it
- again for a period of time. South American countries with
- underconfigured COs (notably Brazil) have required this for years. So
- that's the mandatory delay.
-
- Busy numbers shouldn't be added to the Forbidden Numbers list,
- and numbers that answer and present modem tones won't be. Only
- numbers that answer, but don't present modem tones, should end up on
- the Forbidden Numbers list. This makes sense; if a number is
- answering but not attached to a modem, there probably isn't a modem
- there and the calling end should stop calling and annoying somebody.
-
- If the receiving system is down, that's OK. Either the modem
- doesn't answer the phone, or it answers the phone and brings up a data
- connection, even if no data can be transmitted. The only real problem
- comes with some old systems where, when the system went down, a voice
- message was switched on. But that's rare today.
-
-
- John Nagle
-