Subject: Re: Bad fcs?
To: None <kenn@eden.rutgers.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 06/27/1997 17:34:29
> 
> On Fri, 27 Jun 1997 15:05:35 -0500 (CDT),
> "David A. Gatwood" <marsmail@globegate.utm.edu> wrote:
> > whenever I connect the PB145 (NetBSD) to the 7100 (MkLinux), I get
> > errors....  Initially, I was getting problems with vjc compression,
> > which I turned off, leaving only one that I can't figure out....
> > ppp0: bad fcs 71a2 (twice) followed by a couple with da10, etc.
> 
> Fcs stands for Frame Check Sequence.  A fancy name for a CRC.  So, I'd
> guess the PB can't quite keep up with the data rate thus drops a char
> here and there, making discripancies between calculated and received
> fcs.

I'd bet the error's in the cable. If we were dropping characters,
we'd generate fifo or ring overflows too. Or is logging set to
ignore them?

> > it seems to only happen when a large amount of data is displayed at
> > once, like full-screen programs such as lynx and man.
> 
> Makes sense.
> 
> > I know I can change the syslogd.conf to trash these or redirect to a
> > file, but what's causing these errors, and is there a way to keep
> > the errors from happening, rather than just masking the symptoms?
> 
> Make connection at a slower speed, like 19200 or something.  Or, fix
> the linux serial driver so that it'll do hand-shake properly ;-)

Well, since we don't yet ask the other side to wait, it doesn't matter
if they do handshaking. :-)

Take care,

Bill