🚀 go-pugleaf

as@horizon.co.uk (Richard Ashton) wrote:

> In article <328c8cd8.82562002@news.demon.co.uk>
>            Andrew@gebbie.demon.co.uk "Andrew Gebbie" writes:
> 
> } The problem with the USR and Ascend modems is not that they can't
> } connect at 33.6K, because they can, given good line conditions.  Their
> } problem is in not being able to negotiate down from these high rates
> } to a lower one if the line is less than perfect.  It's alright to say
> } that the phone line doesn't guarantee a 33.6K connection, but there's
> } no excuse for the modems not getting together at a lower, mutually
> } compatible speed.
> 
> The USR Courier *WILL* negotiate down from 33,600 to at least 31,200.

It will?  I've never, ever, seen that happen when dialing Demon.  With
S54=64 I always get either a 33.6K connection or the 'I give up' tone
from the Ascends.  Now, if I disable the 3429 bit rate (S54=96), then
the modems do occasionally negotiate down to 28.8K or even 24K as I
got this morning.

I have seen my modem negotiate down with S54=64 if I dial USR's BBS,
though, even though I call this much less often.  Hence my conclusion,
supported by other people, that there's some negotiation problem
between the USRs and the Ascends.  I don't want to point the finger at
either modem, though, because I bet that each modem can connect under
any conditions to another of the same brand.

> As I have never had a connection to the COLT at less than this, or a
> failed negotiation I do not know whether it will go down to 28000.

Wow.

> I suspect it will as I ocasionally see the Courier retraining.

I can't see this, having an internal modem, I guess.

> } Now, unless you are lucky and have good line quality:
> }
> } 4.  Get bored with having to redial 3 times out of 4.
> } 5.  Set ATS54=96 and put up with max 31.2K connections
> } 6.  Live grudgingly ever after
> 
> I guess I am lucky, all 30 years worth of doing async comms, lucky.

Ouch.  Don't get me wrong, I don't want to run down your knowledge and
experience in this field.  Why do you think I spend so much time
nagging you and others for information, if it weren't for the feeling
that your reliable 33.6 connections aren't just good luck?

As I said earlier, I'm trying to work out whether the problem which I
have with 33.6K connections and the new Beta lines is due to a poor
line or bad settings (or a lack of 30 years worth of async comms
experience).  With your help, I've established that we have a similar
enough environment that I now (almost) believe that the line quality
must be the difference.

The failure to negotiate down could also be a product of a difference
in line quality, although I have more of a problem believing this,
which is why I'm particularly suprised to see that you don't have the
problem.

In another thread, you wrote "I use an overide string ATS54=64 in an
init string, when I want to get a 33,600 connection".  Now, why use
anything other than S54=64 if your modem never fails to negotiate?  I
assumed from what you wrote that you were having the same problems
with failed negotiations, and switched from S54=96 to 64 when you
wanted the 33.6 connection and were prepared to put up with the
redials required.

Andrew
----
Andrew Gebbie    andrew@gebbie.demon.co.uk    Tel: +44 151 632 1605