Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!ucsd!ucbvax!NNSC.NSF.NET!craig
From: craig@NNSC.NSF.NET (Craig Partridge)
Newsgroups: comp.protocols.tcp-ip
Subject: re: IP queuing for X.25 SVC's: conqestion and performance problems.
Message-ID: <9003022256.AA22862@ucbvax.Berkeley.EDU>
Date: 23 Feb 90 13:33:37 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 18


Running IP over X.25 is a notoriously tricky business.  Here are the
two pieces of wisdom I can offer from my limited experience with the
CSNET IP over X.25 driver.

One question is why the queue size ever gets so large.  Are the TCPs
not doing slow-start?  Does the queue never ever drop packets?  Something
sounds odd about the dynamics here.

The other item is a suggestion.  There are cases where there's simply
more traffic that wants to be sent that there is bandwidth over one
X.25 connection to send it.  The CSNET driver had a feature where it
would open additional connections when the queue got large (up to,
I think 6 parallel connections).  There was some simple code to
estimate cost-benefit so connections would close down later if there
wasn't enough bandwidth to justify keeping them open.

Craig