Mumbles to self...RTFM...and Michael Lucas' "Absolute OpenBSD"... and MS KB816627..and the LPRng list responses...
Eventually it will all sink in, and the answer will reveal itself: #sysctl -w net.inet.tcp.ackonpush=1 Extracted from KB816627: SYMPTOMS Printing to a TCP/IP printer port may be slow if you are using the LPR Byte Counting feature or if the advanced TCP/IP options are disabled on the printer. A network trace may show that for every three packets that are sent, there is a "Delayed Ack" before the print device sends an acknowledgement. If the "Delayed Ack" value is set to 0.2 seconds, a 10-MB print job may take approximately 10 minutes. CAUSE The buffer size for reading spooled files is only 4 KB for the Windows print processor and for TCP/IP Port Monitor. This causes 2 packets with 1,460 KB of data, followed by another packet with 1,176 KB of data with the TCP Push bit flag enabled. If the print device ignores the TCP Push bit flag, a "Delayed Ack" is typically generated while waiting for another packet. The "Delayed Ack" value frequently uses a value of 0.2 seconds. A "Delayed Ack" should not occur if the packet TCP Push bit flag is enabled. My OpenBSD 3.2 & 3.4 servers had the "ackonpush" off by default. Enabling it apparently eliminates the "Delayed Ack" being generated. Thanks to Rick Cochran, Patrick, Michael W. Lucas, Microsoft, and the OpenBSD folks for supplying all of the pieces of the puzzle. I put this problem on the back burner a while back, for lack of a solution. The book, especially the section on sysctl provided the final pointer. It's dead simple now that I know it-but if you Google "ackonpush" you get nothing of value... As for Microsoft; there are big, screaming clues in the KB article, and they made no sense until just this morning. Now they make perfect sense. Jim ----------------------------------------------------------------------------- YOU MUST BE A LIST MEMBER IN ORDER TO POST TO THE LPRNG MAILING LIST The address you post from MUST be your subscription address If you need help, send email to [EMAIL PROTECTED] (or lprng-requests or lprng-digest-requests) with the word 'help' in the body. For the impatient, to subscribe to a list with name LIST, send mail to [EMAIL PROTECTED] with: | example: subscribe LIST <mailaddr> | subscribe lprng-digest [EMAIL PROTECTED] unsubscribe LIST <mailaddr> | unsubscribe lprng [EMAIL PROTECTED] If you have major problems, send email to [EMAIL PROTECTED] with the word LPRNGLIST in the SUBJECT line. -----------------------------------------------------------------------------
