Conference 7.286::fddi

1391.0. "FDDI and LAT printing" by BACHUS::DEMEYER () Mon Jul 04 1994 12:03

Hello,

A customer of ours reports an FDDI related printing problem ( or vice versa ).

Their configuration consists of 2 VAX7000 connected via FDDI . The FDDI ring
is also bridged to Ethernet .
On the ethernet they have lots of PC's , a microvax and Terminal servers ( dec
and nonDEC ) . 
They have 4 Xyplex printservers (ds200 lookalike) . These Xyplex printservers
have 4 ports : 2 parallell plus 2 serials . The problem is related to printing
on the parallell ports in combination with FDDI .

When they print via a queue , defined on one of these 2 VAX7000's(FDDI) , on
a printer connected to one of the Xyplex printservers parallell ports their
print output is incomplete . E.g. : If they print one page only the first few
lines are printed , if they print several pages only the first page gets
printed and the rest gets lost .

If they setup their print queues on a microvax( Ethernet interface ) they have
no problem printing to the same Xyplex parallell ports .

If instead of printing to the parallell ports of the Xyplex they print to the
serial ports then there is no problem .

If instead of printing using the LATSYM symbiont they use a COPY command to the
LTA port there is no problem .

What is the difference on LAT/FDDI level between printing via the queue or 
a direct COPY command to the specified LTA port ?

The line buffer size of the FXA line is 1498 .

Any suggestions ?



Thank You,


Luc .

    Same text I put in NOTED::LAT notes file:
    
    What version of OpenVMS is the customer running?
    
    Has the customer installed the latest CSC patch kit for OpenVMS LAT
    software (CSCPAT_0511 V3.6)?
    
    Mike

    Hi Mike,
    
    Installing CSCPAT_0511036 did it !  I don't want to be annoying but do
    you have any idea what went wrong ?
    
     
    Luc .

    I only have a hunch.  LAT tries to use large packets when it is
    communicating through an FDDI adapter.  Unfortunately, it is possible
    that the device may be on the other side of a 10/100 bridge in which
    case, LAT is supposed to use ethernet sized packets.
    
    There was a bug (fixed in the CSC patch kit) where LAT would try and
    send a message bigger than 1500 bytes to a system on the other side of
    a 10/100 bridge.  Naturally, the 10/100 bridge does not forward this
    packet and the remote node never gets it (and the LAT connection times
    out).
    
    Can't say for sure without more evidence but it is possible that your
    customer was experiencing this problem and it is fixed in CSCPAT_0511
    V3.6.  It is also fixed in OpenVMS VAX V6.1 (and OpenVMS AXP V6.1).
    
    Mike