On (10 May 98) Will Honea wrote to Stephen Haffly...
Hi Will,
SH> I am connecting at 40-48Kbps, I am getting many more of these FCS
SH> errors.
 WH> SH>
SH> I tried running the PMLM of SIO, and found that I was getting
SH> overruns periodially.  This appears to coincide with my FCS errors.
 WH> SH>
SH> What causes the overruns.  What cure is there?  I have RCS/CTS
SH> enabled, which I thought was the best settings to use.  Are there
SH> other modem and/or SIO and/or OS/2 settings I should look at?  I
SH> have tried both the current SIO 1.60d and the beta SIO2K, beta 8
SH> drivers.
 WH> Depends on the error itself.  I usually get one or two during the
 WH> negotation phase and another couple at disconnect.  I get them
 WH> periodically and if I check the line quality monitor after a bad
 WH> session I usually show a poor quality connection, ie. noisy.  I tried
 WH> slowing the connect speed down to 33.6 and 28.8 during an especially
 WH> bad sequence and all the FCS errors went away.  Try that and see if
 WH> it's speed related.  You may be faster than your lines can support
 WH> since only a small fraction of the copper lines will support 53k, the
 WH> 'legal' max.  I've also seen some reports where people trying to use
 WH> 230k baud locked improved things by dropping back to 115k or even 56k.
 WH> That's a function of your machine, tho, and not the modem or
 WH> connection.
During connect, I get This:
 PPP: Invalid protocol 0x820
 PPP: Invalid fcs
After this, I don't see any Invalid fcs messages until I am connected,
then they happen randomly during the session.  I haven't noticed them
during disconnect.  What are you using for line quality monitoring?  I
used pmlm the once, and that is where I saw that it was overruns.
Shouldn't error correction handle those type problems between modems
before the data are sent on to the computer?
Line noise may indeed be a factor, since I have gotten 40K and 42K
connects most often.  I have not been using 230K as port speed, but
115.2K  I'll try backing it down to 56K and see what happens.
Thanks for the input.
TTYL,
Stephen
Team OS/2, Team GEOS
OS/2 & New Deal Office 98 - A great combination.
... OH NO!  Not ANOTHER learning experience!
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