PE> The problem is more fundamental than that.  Even if the lines
PE> are noisy at 28800, EC should still be negotiated.  EC was not
PE> something designed to be used purely on good lines, after all!

IS> Yeah, but 'should' assumes things, which often prove unrealistic in
IS> practice; this is why you need to be able to get at the tunable parameters
IS> .. the idea of pulling modems out of the box, like toasters, and having
IS> them make perfect 'toast' first time is simply unrealistic, unless you're
IS> blessed with wonderful lines and just the right amount of local loop ..

The point tho is that V34 is supposed to automate that,
not require the user to understand and do that stuff.

PE> And if the lines are so lousy that you can't
PE> get any of the EC characters through,

IS> That's one possible reason why EC isn't happening, maybe ..

I cant see that either. They are supposed to connect at a low
enough rate that can be sustained, and negotiate EC on that,
and later fall forward up from that if thats feasible. Its a
bit pointless having a situation where you cant successfully
negotiate EC when its PRECISELY what you need for the poorer lines.

A VERY fundamental logic problem there.

PE> the modems with their default settings have no right to be
PE> connecting at 28800.  That is lying and cheating.  They should
PE> be connecting at 19200, or whatever the lines REALLY allow.

IS> Yeah, well.  'Should' depends on many manufacturer assumptions,
IS> like exchange type/s, local loop losses, all sorts of things.

V34 aint supposed to assume, its supposed to MEASURE and adjust.

IS> It's not a perfect network yet, and these things
IS> are stretching the limits of voice telephony.

Yes, which is why V34 is designed to measure whats there and do the
best it can with what it finds, even if thats a rather poor thruput.

IS> They're optimised, in default configuration, for
IS> a particular set of conditions, and according to
IS> the skill of each manufacturer - a known variable.

Thats not what V34 is about tho. Its supposed to measure and adjust.

IS> As I said, you _should_ be able to tune its 'aggressiveness'
IS> of trying for a particular speed, with a given set of
IS> conditions - which are complex: tx and rx signal levels,
IS> delays, near and far echo levels, signal to noise, all that.

The whole point of V34 is to avoid the user having to do that stuff.

IS> Lewin would know a lot more about this, from the perspective of
IS> the maker tuning those characteristics via the DSP, and about what's
IS> available to the manufacturer who uses the DSP pretty well raw, like
IS> Netcomm, Dataplex and a few others, and those who just bolt in the
IS> pre-coded 'solution' best-guess stuff. Then, how much access the USER
IS> has to play with it, by published or possibly unpublished commands.

Thats NOT what V34 is about, its meant to automate that stuff.

Thats the whole point of it, and why it does a lot better than V32bis.
@EOT:

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