RS> But on a line thats not so bad that they need to retrain, you
RS> shouldnt be seeing errors at the line level that get past the
RS> EC between the modems, to be caught by the Zmodem error check.

JT> I'm just repeating what I experience with this system.

Yes, but I was questioning the interpretation of what you do experience.
Yes, there is a problem seen at the Zmodem level. No, that does not mean
that you are actually seeing line errors producing those Zmodem errors.

JT> ZModem sees errors, and there is an associated drop in cps rate.

The cps rate will ALWAYS drop whichever level the errors are
seen at because the resends have to result in a lower thruput.

JT> From the commands and setup I have fed
JT> the modem, I believe that EC is enabled.

Yes, and the evidence from the result when you disable EC does
indicate that its normally achieve. Corse you cant be absolutely
certain on that evidence alone that its actually being achieved
on the PARTICULAR dud calls. I have seen situations when repeated
calls to the same modem on the same line at each end occasionally
results in a PARTICULAR call not actually achieving EC at all.

With some modems that stands out like dogs balls on the front panel display.

JT> What my spastic modem does behind my back is beyond my control.

Sure, but I was discussing whether its line errors that produce the
errors at the Zmodem level. Dont believe that one. Something else is.

JT> And yes I'm sure I have EC turned on, I've tried it turned
JT> off once, sheez it was bad. IMO, EC *improves* the situation,
JT> but does not always completely eliminate errors.

RS> Yes, if the line is so grossly bad that the
RS> modems retrain, you can THEN see Zmodem errors.

RS> And the line must be that grossly bad if it drops out at all.

JT> Out of the 10 odd lines going to the same place, one is by far the
JT> worst. I remember asking ages ago if he had any problem reports by other
JT> users, but there were none.  Most likely it is a compatibility issue.

Maybe. You can certainly get some weird combinations with modems. At one
time with lots of us calling here roughly daily, just one person ever saw
a significant level of problem with a particular modem, the others had no
problems at all, with the SAME modem. Turned out when we measured his line
with a modem that can do that, his line is very measurably worse. Combined
with Pauls which is nothing to write home about, and a his modem with a
quirk that made it exhibit a significant number of dud calls with him.

RS> Its even possible that the flow control in the transmitting
RS> modem has some deficiencys in the retrain situation.

JT> Maybe, I think it is just my modem that is intolerant of bad lines.

Its unlikely to be JUST that, coz that should see the thruput reduced
significantly as the EC between the modems wastes a lot of time on fixing
errors. It shouldnt produce Zmodem errors if it was JUST that tho.

RS> If line errors are getting past the modems EC you have a problem somewhere.

JT> I wish I knew where,

RS> Most likely an obscene line if it drops out at all. It shouldnt,
RS> just fall back speed wise to a speed that isnt too bad error wise.

JT> Given a choice of slow, or dropped line, I'd take slow any day.

True. It may well be that that particular pair of modems combined with
your and the BBS modems phone line cant actually successfully negotiate
an appropriate set of speed etc conditions to make the session atleast
usable. And the Zmodem errors are actually just timeouts seen when they
are mindlessly retraining trying to negotiate the session params, and that
quite a bit of the time they just give up and the line drops right out.

JT> With slow, the data still gets across whatever way.

And you arent paying for the time, you are for fresh connects.

JT> I have also noticed this with my older system that
JT> I used to use, a different pc, modem altogether.

RS> Which points the finger at the line and/or the BBS modem.

JT> Either way, fuck all I can do about it except not call that line.

Well, a better modem at your end may well have more success calling
that particular modem/line if everyone else does better. Corse you
would want to try that and see rather than just buy and pray.

JT> If I call late at night (er, morning), it tends to
JT> be better, but at peak hour (evening) it's a mess.

RS> That could either mean that the line is lousy due to crosstalk
RS> from other calls or its what Telstra calls an HR joint, high
RS> resistance. Tends to be moister at might so conducts better.

JT> May very well be, I'll ask again on reports on that particular
JT> line, last time I asked, he said there were no problems.

You should also see a marked difference between summer and
winter nights with an HR joint, particularly heat wave nights.

JT> It must be just bad line noise, on certain systems,
JT> i CAN'T get over 24,000 odd, yet I've called interstate
JT> at 28.8 without even a hint of a glitch.

Yeah, certainly the line is down on performance, BUT the whole point
of V34 is that it should be able to get a good solid session even with
lines that are down considerably performance wise. Albeit with the
thruput down a little because the line isnt anything special at all.

It shouldnt produce that obscene mindless retraining and dropout stuff.

One of the BBSs I used to get my mail from had a similar situation,
just one line/modem that was rather indifferent performance wise.
The other lines got full speed connects every time. This particular
one would connect down from the max one step at times, and often fall
forward up to the max during the call too. Thats how its supposed to
work, the speed increasing and decreasing as required. And falling
back and falling forward too, not full retrains.

JT> In today's mail, there was a message from a guy that downgraded
JT> from an Avtek 28 to a banksia 34.  He *used* to get 28.8 all
JT> the time, now he says he's lucky to get over 24 odd.

Certainly powerful evidence that the Banksias
have a problem in that particular situation.

JT> I'm believing more and more that a modem
JT> change will make all my problems disappear.

Yeah, looks like it.

JT> The only thing that is stopping me, is the adaptive answering
JT> works ok most of the time, and I use it.  Even if the data is
JT> reliable on a new modem, if the fax don't work, it's no good to me.

Yeah, life wasnt meant to be easy |-)
@EOT:

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