Subject: RE: modems

From: "Pankaj Bhandari" <[email-masked]>
Date: Tue, 11 Jun 2002 13:56:15 +0530

Screeching occurs during handshaking.

During the handshaking, the frequency is audible, thats the reason for screeching.

> -----Original Message-----
> From:	Bill Cunningham [SMTP:[email-masked]]
> Sent:	Tuesday, June 11, 2002 12:53 PM
> To:	[email-masked]
> Subject:	modems
>
> I know modems communicate on the physical layer by electrical pulses or
> binaries sent on copper wires. Is that screeching you hear electrical
> communication? Computers don't communicate by screeching...or do they?
>

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From: David Frascone <[email-masked]>
Date: Tue, 11 Jun 2002 09:47:20 -0500

Ummm . . . how 'bout:  During handshaking the modem's speaker is on.

-- 
David Frascone

           Winston Peters, a rebel without a caucus.

---

From: "Bill Strahm" <[email-masked]>
Date: Tue, 11 Jun 2002 09:20:52 -0700

I'll go a little farther...

Common configurations for modems leave the speaker on during
handshaking, but turn it off during normal data traffic...

When I was doing a lot of modem programming I remember there were ATA
commands that would turn off the speaker, or leave it on all the time...
Really want to annoy a coworker, leave their modem configured not to
turn off the speaker...

Now the shrieking is basically the sound protocol that lets both ends
know how to communicate... Each sound has its own meaning and I believe
is still backwards compatible to 300 baud... (Haven't played with modems
since the 14.4 days myself though, so that could have changed with the
56K modems)

There are some good books on the topic depending on what you want to
know

Bill
-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
David Frascone
Sent: Tuesday, June 11, 2002 7:47 AM
To: Pankaj Bhandari
Cc: Bill Cunningham; [email-masked]
Subject: Re: modems

-- 
David Frascone