RE: modems

["VILLARREAL, STEVE (SBC-MSI)" <sv9199 at sbc.com>]

Can someone forward a copy of the current v.90 standard ?  I've been trying
to find it on the web.  Not successful though.


Steve Villarreal 
Product Design
e-mail: SV9199 at sbc.com
Phone:   210-886-3680
	



-----Original Message-----
From: Vernon Schryver [mailto:vjs at calcite.rhyolite.com]
Sent: Monday, June 17, 2002 8:37 AM
To: ietf at ietf.org
Subject: RE: modems


> From: TOMSON ERIC <Eric.Tomson at siemens.atea.be>

> ...
> That's why V.90 could only exceed this limit (56.000bps in
> downstream) by using compression techniques.
> ...

Doesn't v.90 exceed 30 Kbit/sec because in one direction it is not
analog for a significant part of the path and plays games with the
digital to analog convertors on the single local loop, and so has more
than 3 KHz at 30 db to play with?  Isn't v.42bis the modem compression
standard?  Hasn't anyone who has actually read the standards or used
v.90 modems with v.32bis and done measurements seen better than 56
kbit/sec or at least noticed that v.42 and v.42bis can be turned on
and off independently of each other and of the raw bit rate that v.90
negotiates?

This whole thread is not only of limited relevance to this mailing
list or much of anything in this century, but not as technically
accurate as one might hope.


Vernon Schryver    vjs at rhyolite.com