Ultrix 3.1 (VAX) hangs just after dial out

[Shin Yoshimura]

I am running Ultrix 3.1 with Japanese extension on a MicroVAX II.  It
has DHV11, 8 asynchronous port.  I am using two modems(T-2000) for
both of incoming/outgoing uucp.

Sometimes, the system hangs.  It is not panic down and no core dumps,
just hang up.  No answer comes by ping from other host, and DTR drops
on modem port.  It is completely down.  On syslog and messages, no
messages comes.

But I found on LOGFILE of uucp, it occured just after dial-out uucp
session.

The log is as follows,

On outgoing side(microVAX II)
--------------------------------
uucp cotton (9/16-3:26-15743) using device (tty01, fd= 7, brand = tb-t - generic
)
uucp cotton (9/16-3:26-15743) SUCCEEDED (call to cotton )
uucp cotton (9/16-3:26-15743) OK (startup)
daemon cotton (9/16-3:26-15743) REQUEST (S D.komabab0RLW D.komabab0RLW daemon)
daemon cotton (9/16-3:26-15743) REQUEST (S D.komabaX0RLU X.komabaX0RLU daemon)
root cotton (9/16-3:26-15743) REQUEST (S D.komabab0RLg D.komabab0RLg root)
uucp cotton (9/16-12:26-206) using device (tty01, fd= 8, brand = tb-t - generic)
--------------------------
the session at 3:26 is not completed.

On incoming side(Sun-3/80)
------------------------------------
uucp komaba (9/16-3:25-24159) OK (startup)
uucp komaba (9/16-3:25-24159) REQUESTED (S D.komabab0RLW D.komabab0RLW daemon)
daemon komaba (9/16-3:25-24159) COPY (SUCCEEDED)
daemon komaba (9/16-3:25-24159) REQUESTED (S D.komabaX0RLU X.komabaX0RLU daemon)
daemon komaba (9/16-3:25-24159) COPY (SUCCEEDED)
daemon komaba (9/16-3:25-24159) REQUESTED (S D.komabab0RLg D.komabab0RLg root)
root komaba (9/16-3:26-24159) COPY (SUCCEEDED)
root komaba (9/16-3:26-24159) REQUESTED (S D.komabaX0RLe X.komabaX0RLe root)
root komaba (9/16-3:26-24159) COPY (SUCCEEDED)
root komaba (9/16-3:26-24159) OK (conversation complete)
-------------------------------
The session complete normally.

The system down occurs just after disconnection of phone.  The drivers
of tty have some problem.  I need help for this problem.







--
Shin Yoshimura
Dept. of Chem., Coll. of Arts & Sci., The Univ. of Tokyo., JAPAN