HUPCL and getty... what's going on?!?

[Horst Laumer]

cyamamot at kilroy.jpl.nasa.gov (Cliff Yamamoto) writes:

>Greetings!

>Well I've been losing too much sleep over this, so after weeks of hacking
>I must plea for help.  The situation is...

>I'm implementing a dialback procedure.  When people dial in to the USR HST
>Dual, no problem.  The gettytab is perfect, the autobaud works and everyone
>[...]

>Dialback is the headache.  As soon as the modems connect (after dial back
>and establishing carrier), the Sun drops DTR and kills the connection!  The
>quick fix?  Disable DTR monitor on the USR so the modem ignores the DTR.
>Sure it works, but now the modem doesn't hang up on logouts.  The users
>must manually hang up their end.

>What I've found... With a 232 protocol analyzer as soon as CD goes high
>(for carrier detect) the sun drops DTR.  I've tried the breakout box, but
>I'd like to keep the RTS/CTR and DSR/DTR stuff kosher.

>So how do I know getty is my HEADACHE???!?

I had the same problem on Dial-In with my 386-box running ISC. After
missing quite as much sleep as you did, I found the reason for dropping
DTR **was** getty, since this getty closes the line on an successfull
open() (indicated by CD) and opens it again. Assuming your problem in
an inter-system-connection, (a) try another getty (f.e. xgetty, which
is PD and has an option **not** to close the line on successfull open()),
(b) install it on either side of the line. Another idea would be to use
a port **without** modem-control for dial-out and let the modem close
the line on loss of either carrier or DTR.

Hope this helps you.

(I do not post the xgetty-sources, 'cause the archive is of 68 kB)

sincerely HL
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