Conference clt::smg

1566.0. "SMG and LAT I/O" by NOTAMI::A_ANDERSON (CX03 2/H13 NSU/VAX MacGhille Aindrais) Thu May 15 1997 21:05

Hello All,

I have a customer calling with the following situation.

He has 34 DECservers on a small lan and is using SMG to send terminal I/O to
Terminals connected to the DECserver (DS200 and DS90TL).  When the SMG
application was running on a VAX 3100/80 and VMS 5.5 all was ok.  Now they have
replaced the 3100 with a Alpha 1000 and VMS 6.2-1H3.  Now they frequently get
into a state where the DECserver port in in an input Xoffed mode.  This can only
occur if the terminal sends an XOFF and never sends an XON.  Until the Terminal
sends the XON the DECserver cannot send and I/O nor can it allow the connection
to drop.  If they type a ^Q on the terminal then it recovers.  But if they
reboot or restart the application while the DECserver is locked in a input
XOFFED mode the SMG application's connection to the DECserver gets queued.    

Normally I would say this is a terminal issue.  but why would changing the VAX
to an Alpha cause the problem?  Does SMG on a Alpha VMS VMS V6.2 send larger
screen updates than SMG on a VAX VMS V5.5-2.  Perhaps we are overrunning the
terminal.  Perhaps the Alpha is fast enough that data is being pipelined to the
terminal causing it to get overrun.  I am just fishing for ideas.  

Is SMG supported over LAT?  Is there a SMG SPD avaialable I could not locate 
one in VTX IR?

 
Any help wopuld be apprecieted I do not know what to tell this customer except
to suggest he rewrite the application using LAT qio's, this is what our teams
consultant is telling me. 



Thanks 
Alan S. Anderson
Network Support CSC CS

    The Alpha SMG code is identical to the VAX SMG code.  So, I don't see
    what difference it would make moving to an Alpha.  It sounds like a
    terminal issue.
    
    Frank