RE: Modem Retrains
Leonard (pmfan@infinetgroup.com)
Mon, 25 Aug 1997 11:52:31 -0700 (PDT)
On Mon, 25 Aug 1997, Tom Samplonius wrote:
> > asyncmap 0x00000000
> >
> > Fixes basically everything. The file now downloads at 10.54 K/s, I have very
> > few slowdowns whatsoever.
>
> This is bogus. A all-zero async map means that no characters are
> escaped, so everything is transmitted as-is. So, so all those
> "special characters" are still being transmitted over the link. Besides
> "special characters" aren't supposed to cause retrains, because the
> connection should be 8-bit clean.
>
> However, if your asyncmap contains a lot of bits, PPP will have to
> escape a lot of characters, causing a lot of extra traffic to be
> transmitted.
Well, could Jaime's suggestion (see below) be possible then? It may be
possible that DUN<->ComOs are trying to do both hardware and software flow
controls at the same time, thus causing "confusion" and eventual
"lockups".
On Mon, 25 Aug 1997, Jaime Bozza wrote:
>Looking at it deeper, the async map is turning off CTRL-S and CTRL-Q,
>which are XON/XOFF ... Could software flow control be confusing
>something
>somewhere? That would certainly cause the modem to simulate a "lockup",
>which is what causes the eventual "Call Circuit Disconnect" to show up.