Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!rex!uflorida!gatech!hubcap!ncrcae!ncr-sd!se-sd!cns!dltaylor
From: dltaylor@cns.SanDiego.NCR.COM (Dan Taylor)
Newsgroups: comp.sys.amiga.datacomm
Subject: Re: 19200bps
Message-ID: <942@cns.SanDiego.NCR.COM>
Date: 8 May 91 18:28:05 GMT
References: <1991May5.185645.12902@cunixf.cc.columbia.edu> <1991May5.201708.452@cec1.wustl.edu> <dillon.7375@overload.Berkeley.CA.US>
Organization: NCR Corp. SE-San Diego
Lines: 17

In <dillon.7375@overload.Berkeley.CA.US> dillon@overload.Berkeley.CA.US (Matthew Dillon) writes:

>    A normal phone line has a bandwidth of around 38KBaud.  As any

There are still a LOT of subscriber lines with 3KHz filters.  That is
NOT a misprint, 3000 Hz.  Some urban subscriber lines have 38KHz, but
not many.  The higher data rates are achieved by compressing the
information in various ways, and using schemes like "trellis coding" to
send more "bits per second" than the phone lines can normally stand.  Of
course, leased point-to-point lines are not normally filtered like this.
That's why the older "high-speed" modems worked on them, long before
most subscriber lines could.  The FAX people have this problem, too.
Their machines have many graceful fallback modes.

Personally, I WANT an optical ISDN connection as my subscriber line.

Dan Taylor