In a message dated 09-11-96, Bill Grimsley said to Michael Raiteri:

TP> CONNECT 28800/ARQ/V34/LAPM

MR> BTW did you use your previous settings ie AT&F1&K0

BG>As no /V42BIS response was indicated, I'd say that was rather obvious.  :)

I agree but I wanted to know if he had set S15=136 as well to force the LAPM
connect.

MR> more importantly how long did you stay connected to the BBS.  I can get a 
MR> high speed connect but it drops carrier with GSTN 
MR> Cleardown after about 30 
MR> seconds.

BG>Which means that it was a non-error-correcting connect, as according to the 
BG>USR manual, GSTN cleardowns only ever occur with non-ARQ 
BG>calls.  Anyway, why are you still not seeing LAPM or MNP4 
BG>with this modem  - have you tried calling it with either 
BG>your modem's V.42 detect phase, or its 3429 symbol rate 
BG>disabled?  One of those should solve your non-ARQ problem 
BG>(it's generally the former). 

I am seeing LAPM connects. When I use S15=136 I get a LAPM connect which lasts
about 20 seconds maximum.

If I disable the symbol rates right down to 19200 with S33=62 I don't even get a
connect.

The only way I can get a reliable connect is with S15=136&N11 to lock max
connect speed at 21600.

Put it all together with what you said above and it doesn't make sense. I'm
getting an error correcting connect but losing carrier with GSTN Cleardown.
Telstra are certain that it is not my phone lines (see other message "noisy
lines") and that it must be my equipment.  This takes me back to my original
statement some weeks ago that I reckon my modem is a lemon.

BG>The problem could also be at your end of the link, for that matter...

Not the phone lines anyway but could be my equipment ie modem or wires.

MR> I had to settle using the &Nx command to limit my logon speed to 21600 to 
MR> get any sort of consistent and reliable connects.

BG>That's certainly not the best method of connecting at a lower link rate, as 
BG>the connect is then locked at a specific speed, and won't 
BG>shift up or down, nor retrain if necessary, and on less-
BG>than-perfect lines I'd expect to see the modem dropping 
BG>carrier fairly regularly.  You'd be much better off forcing 
BG>a lower initial connect speed by disabling the modem's 
BG>higher symbol rates, which will then allow the modems to 
BG>retrain and/or speed-shift within that specific symbol 
BG>rate's capabilities.

BG>I'm not conversant with each individual symbol rate's highest possible 
BG>connect speed, but 33600bps requires 3429, and 28800bps and 
BG>31200bps require at least 3200, so it might be worth 
BG>experimenting by disabling say 3429, 3200, 3000, and maybe 
BG>even 2800, depending upon each rate's maximum speed.

Doesn't work either. I tried them all until I reached S33=62 which disables
right down to I think 19200 and still no go.  Goes from a LAPM connect for a few
seconds to no connect at all.

heres the capture file
ATI6I11
Texas Instruments RK 33600 Fax Link Diagnostics...

Chars sent                    0      Chars Received                0
Chars lost                    0
Octets sent                   0      Octets Received               0
Blocks sent                   0      Blocks Received               0
Blocks resent                 0

Retrains Requested            0      Retrains Granted              0
Line Reversals                0      Blers                         0
Link Timeouts                 0      Link Naks                     0

Data Compression       NONE
Equalization           Long
Fallback               Disabled
Protocol               NONE
Speed                  19200/21600 
Last Call              00:00:00

Disconnect Reason is MNP Incompatibility

USRobotics Sportster 33600 V.34+ Fax Link Diagnostics ...

Modulation                  V.34
Carrier Freq     (Hz)       1600/1800
Symbol Rate                 2400/2400
Trellis Code                64S-4D/64S-4D
Nonlinear Encoding          ON/ON
Precoding                   ON/ON
Shaping                     OFF/ON
Preemphasis      (-dB)      6/10
Recv/Xmit Level  (-dBm)     33/11
SNR              (dB)       32
Near Echo Loss   (dB)       20
Far Echo Loss    (dB)       61
Round Trip Delay (msec)     3

OK

Using S15=136 I get

ATI6I11
Texas Instruments RK 33600 Fax Link Diagnostics...

Chars sent                   33      Chars Received             6167
Chars lost                    0
Octets sent                  26      Octets Received            6167
Blocks sent                   8      Blocks Received              80
Blocks resent                 0

Retrains Requested            0      Retrains Granted              0
Line Reversals                0      Blers                         0
Link Timeouts                 0      Link Naks                     0

Data Compression       NONE
Equalization           Long
Fallback               Disabled
Protocol               LAPM
Speed                  24000/26400 
Last Call              00:00:17

Disconnect Reason is GSTN Cleardown

USRobotics Sportster 33600 V.34+ Fax Link Diagnostics ...

Modulation                  V.34
Carrier Freq     (Hz)       1829/1920
Symbol Rate                 3200/3200
Trellis Code                64S-4D/64S-4D
Nonlinear Encoding          ON/ON
Precoding                   ON/ON
Shaping                     ON/ON
Preemphasis      (-dB)      8/10
Recv/Xmit Level  (-dBm)     37/10
SNR              (dB)       31
Near Echo Loss   (dB)       13
Far Echo Loss    (dB)       56
Round Trip Delay (msec)     3

OK

never online long enough for aty11.

MR> I mentioned in a previous message - it appears not all Dynalinks have this
MR> problem with that BBS.  The one at Dynalink tech support sure did though. 
MR> Maybe I've just got a dud.

BG>Have you posted the results of an on-line ATY11 probe yet?  
BG>Those figures will give you a pretty good indication of 
BG>where the problem lies (as will the S/N ratio, if your 
BG>modem is capable of displaying it with ATI11).

Never online long enough for ATY11 and yes the modem can display ATI11 (see
above).

I've just decided there doesn't appear to be a cure and settle for the &N11
connects.

Cheers
Mike
Internet: mraiteri{at}dyson.brisnet.org.au
___
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