[Techtalk] External 56k modem

Maria Blackmore mariab at cats.meow.at
Mon Jun 30 09:42:58 EST 2003

On Sun, 29 Jun 2003, Staci wrote:
> On Mon, 30 Jun 2003, Maria Blackmore wrote:
> > You can reset the modem with "ATZ" and get it to dial the number with
> > "ATDT" and follow with the number, eg dialling up to where I work would be
> > "ATDT08451200387"
> Gotcha.  I got it to dial....

This is good :)

> Hey, wait, what kinda number is THAT?  Where are you anyway? (If you
> don't mind my asking.)

That, is our dialup access number :)

I'm in the UK

The number breaks down as follows:

0845	Local call rate from anywhere in the country, a non-geographic
	number that can terminate anywhere inside or outside of the
	country, but still shows up on the customers bill as a local rate
	call.  Natty huh? :)

120	The number belongs to Kingston Communications

0387	er .. us :)

The number is actually routed to an exchange somewhere in the south of
England, whereupon it's routed onto a real set of phonelines, and sent off
to us.

> But no such luck.
> IT doesn't actually connect.

This isn't good :(

> I think that's why I'm not getting any log-messages anywhere.

That would definately explain it, yes.

If you have the speaker turned on, can you describe the sound it tails off

a 56k modem connect should start off with a sort of squigly sound,
followed by the same squiggly sound but higher pitched, then a higher tone
for a short time, which should sound like it's being joined by some others
and have a kinda "beating" sound.  The next bit I can only describe as
next you'll hear two "boings", and then a little bit more "BLAAAA" kinda
noise, and it'll be connected.

The boings should sound clean and clear, with no echo (the modem is using
them to calibrate it's internal echo canceller).

Anyway, here is someone who's spent far too long listening to modem
connections being made :)

It's quite important how far it gets, as to what kind of "broken" it is,
and what might need to be done next.

It could, possibly be a noisey line, or you could need to update the
firmware on the modem, or your ISP may be using modem racks that don't
like your particular modem, in which case you can try adding a few commas
after the telephone number to make the modem pause before attempting to
talk to the ISP's modem rack.  I've found that three commas works well
enough for modems like this connecting to our racks, but our racks have no
delay before answering the call and starting handshake (they actually
answer the call without it ringing, which confused the hell out of one
particular make of modem that I can't remember the name of).  Try using
before 1 and 6 commas, you may get a connection like this :)

> The one I've got?
> CNET V90/56k fax-modem, exterial serial.

hmmm ... drawing a blank there

have you asked your ISP if they've had anyone have any problems connect
with a similar modem?

> The one I could get....well, there've been many offers, from fellow
> geeks who have 56k dustcatchers laying around at home. ;)

Or, at a pinch, you could get a new modem :)

Try going through the tests and stuff I suggested above, and use a phone
on the same line to check to see how the line sounds.  It should be clear
and quiet, with no hissing or crackling.  If it isn't, then you need to
kick your telco's butt :)

good luck


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