[comp.protocols.appletalk] HELP! Timeouts while printing to LaserWriters

hopperj@dayton.saic.com (12/08/90)

I have an appletalk LAN here with four bridges (four zones).  There is
probably some 80 appletalk users.  We also have MS-DOS machines connected
to this network using FlashTalk boards.  PROBLEM:  We are getting TIME-OUT
errors when printing to various LaserWriter/NT printers.  When we
disconnect some users from the main network and create a "mini" network,
the problem disappears.  I have checked all wiring, terminators, etc.  This
problem has been going on for a while, but I was just informed.  Can anyone
come up with a fix??  THANKS!

James Hopper
SAIC

bschmidt@bnr.ca (Ben Schmidt) (12/10/90)

In article <1990Dec7.120246.1357@dayton.saic.com> hopperj@dayton.saic.com 
writes:
> I have an appletalk LAN here with four bridges (four zones).  There is
> probably some 80 appletalk users.  We also have MS-DOS machines connected
> to this network using FlashTalk boards.  PROBLEM:  We are getting 
TIME-OUT
> errors when printing to various LaserWriter/NT printers.  When we
> disconnect some users from the main network and create a "mini" network,
> the problem disappears.  I have checked all wiring, terminators, etc.  
This
> problem has been going on for a while, but I was just informed.  Can 
anyone
> come up with a fix??  THANKS!

Beg, borrow, steal a copy of Inside LaserWriter ( I think that's what it's 
called.)  There are a couple of timeout parameters for the LaserWriter 
that are stored in non-volatile memory.  One for the total job, and one 
for the longest it can wait for consecutive commands within the same print 
job.  You might be able to band-aid your problem by changing the latter.  

But as your comments indicate,  the real solution might be to pin down why 
the the laserwriter is timing out: 

- localtalk network too congested to get print job packets sent within 
printer's timeout parameters.  (could be caused by low-performance 
appletalk routers, or interference from particular nodes, especially if 
they are using FlashTalk as opposed to LocalTalk (230kbit/sec) data rates. 
 possible, since problem disappears when you segment your network.)

- localtalk network unterminated or over-extended somewhere leading to too 
many dropped localTalk packets between node and printer (possible since 
problem disappears when you segment your network.)

- application printing routine broken -- too much time between packets 
(unlikely since you can print when you segment your network)

- job too large for laserwriter given it's default timeout parameters 
(reduce job size, add laserwriter memory, or switch to faster laserwriter. 
 unlikely since you can print when you segment your network.)

<sigh>, whatever happened to plug and play?


Ben Schmidt     Bell-Northern Research, Ltd.   Ph: (613) 763-3906
Information     P.O. Box 3511, Station C       FAX:(613) 763-3283
Technology      Ottawa Canada K1Y 4H7          bschmidt@bnr.ca

rbrink@hubcap.clemson.edu (Rick Brink) (12/12/90)

From article <1990Dec7.120246.1357@dayton.saic.com>, by hopperj@dayton.saic.com:
> I have an appletalk LAN here with four bridges (four zones).  There is
> probably some 80 appletalk users.  We also have MS-DOS machines connected
> to this network using FlashTalk boards.  PROBLEM:  We are getting TIME-OUT
> errors when printing to various LaserWriter/NT printers.  When we
> disconnect some users from the main network and create a "mini" network,
> the problem disappears.  I have checked all wiring, terminators, etc.  This
> problem has been going on for a while, but I was just informed.  Can anyone
> come up with a fix??  THANKS!
> 
> James Hopper
> SAIC
Have you run CheckNet on the net?  It sounds like some lost data, or collisions
are killing your connections.  The software drivers for the FlashTalk boards
are probably maximized to keep from tying up the pc waiting on notoriously slow
laserwriters to print.  Given some parameter of default time, the lost packets
timeout the boards.

The lost or collisions could be the unavoidable kind, but you could have a
mac with a bad appletalk chip (serial chip).  Then again, it may just be 
traffic across the bridges is tying things up.

Monitor the traffic between the two machines in question.

good luck

rbrink@hubcap.clemson.edu