Re: 57600 modems

Michel Carleer (mcarleer@ulb.ac.be)
Thu, 28 Nov 1996 11:59:31 +0100


Jesus,
First, look at Marc Lindahl's mail concerning bandwidth and bitrate.
Secondly, I should have been a little more explicit when speaking of
special cables for ISDN: in fact ISDN uses the same wires as normal voice
or modem telephony, but for ISDN these wires have to be in very good shape
and also properly laid down. Sometimes telcos have to lay new lines because
the existing ones are too old, or are subject to electromagnetic noise
because they are too close to other cables. I suppose this is especially
true in countries where the lines are underground and use the same
protecting pipes as the power cables for example. Well, this is what some
people told us on this list.

Michel R.C.E. Carleer
Chimie Physique Moleculaire CPi 160/09
Universite Libre de Bruxelles
Ave. F.D. Roosevelt, 50
1050 Bruxelles
Belgique
Tel: +32-2-6502425
Fax: +32-2-6504232
e-mail: mcarleer@ulb.ac.be

----------
> From: Jesus Maria Arango - Ing. Comunicaciones FSM LTDA.
<jarango@supernet.com.co>
> To: CU-SEEME-L@cornell.edu
> Subject: Re: 57600 modems
> Date: Wednesday, November 27, 1996 10:42
>
> Michel,
>
> There is no doubt that phone companies give between 3000 and 4000 Hhz to
> the end user. So the maximum speed between a number of links should be
> that of the slowest link, which would be the telco pair between users and
> telco switches, which according to my explanation would be 9600 if using
> digital transmission. Give me your comments please.
>