DDM TCP failing with CPD3E34

We've had a good DDM over TCP connection going with one of our customers.
Now it is failing.  What are the trouble shooting steps?

CPE3447
10    01/08/02   14:54:27   QRWXDLL        QSYS        *STMT    QRWXDLL
QSYS
  From module . . . . . . . . :   QRWXDLL
  From procedure  . . . . . . :   SndErrnoMsg
  Statement . . . . . . . . . :   10
  To module . . . . . . . . . :   QRWXDLL
  To procedure  . . . . . . . :   SndErrnoMsg
  Statement . . . . . . . . . :   10
  Message . . . . :   A remote host did not respond within the timeout
period.

CPD3E34
40    01/08/02   14:54:27   QRWXDLL        QSYS        *STMT    QRWXDLL
QSYS
  From module . . . . . . . . :   QRWXDLL
  From procedure  . . . . . . :   SndCPD3E3x
  Statement . . . . . . . . . :   16
  To module . . . . . . . . . :   QRWXDLL
  To procedure  . . . . . . . :   SndCPD3E3x
  Statement . . . . . . . . . :   16
  Message . . . . :   DDM TCP/IP communications error occurred on connect()
to
    Application Server.
  Cause . . . . . :   Error code (errno) 3447 was received while processing
the
    connect() to Application Server function for DRDA/DDM TCP/IP
communications.
    Recovery  . . . :   See any previously listed message(s) to determine
the
    cause of the error; if necessary, correct the error and issue the
request
    again.

CPF4404
10    01/08/02   14:54:27   QDMCLOSE       QSYS        045A     QCNSTERM
QSYS
  Message . . . . :   File QCNDDMF was already closed, never opened or not
from
    this process.
  Cause . . . . . :   A close operation was requested for a file that has
    already been closed, was never opened or was not opened within this
process.
    The close operation was ignored and processing continued. Recovery  . .
. :
     Remove the additional close operation from the program or retry the
close
    operation from the process where it was opened.

CPF9162
40    01/08/02   14:54:27   QCNSMCTL       QSYS        0197     QCMD
QSYS
  Message . . . . :   Cannot establish DDM connection with remote system.
  Cause . . . . . :   An error occurred during distributed data management
(DDM)
    initialization while attempting to establish a DDM connection at the
remote
    location *N with the remote system. Recovery  . . . :   See previously
    listed message CPD3E34. Correct the errors and then try the request
again.
    If message CPD3E34 is listed, see the message listed before it for
meaning
    of error code. If the remote location listed is *N, see the previously
    listed messages in the job log for the cause of the DRDA/DDM TCP/IP
    communications error.


CPF5739
40    01/08/02   14:54:27   QTSLOCK        QSYS        0616     QCMD
QSYS
  Message . . . . :   Cannot assign or release DDM file(s).
  Cause . . . . . :   This system or the target Distributed Data Management
    (DDM) system detected a condition that caused the assign or release
request
    to fail. Recovery  . . . :   See the previous messages in the system
log to
    analyze the conditions that caused the failure. Make the needed
corrections,
    and then try the request again.

Rob Berendt
--
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
Benjamin Franklin