Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!think!snorkelwacker!spdcc!ima!haddock!news
From: news@haddock.ima.isc.com (overhead)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: IP queuing for X.25 SVC's: conqestion and performance problems.
Keywords: rfc877, IP, X25
Message-ID: <16006@haddock.ima.isc.com>
Date: 22 Feb 90 22:42:57 GMT
References: <2452@medusa.informatik.uni-erlangen.de>
Reply-To: jimm@ima.ima.isc.com (Jim McGrath)
Organization: Interactive Systems Co
Lines: 21

In article <2452@medusa.informatik.uni-erlangen.de> eckert@medusa.informatik.uni-erlangen.de (Toerless Eckert) writes:
>I am experiencing some Problems with running IP on top of X.25 (RFC877).
It sounds as though you are running with the D-bit (delivery
confirmation bit) set.  If so, you might consider if you really need
end-to-end confirmation.  Let the DCE do your buffering for you.

Just because you have a 64kb line to the first DCE doesn't necessarily
mean that that all links to the destination DTE are running at that
speed.  Is the Throughput Class facility meaningfully implemented by
your PDN?

A packet size of 1024 should be the optimal size for an MTU of
576.  A window size of two should be OK if you run without The D-bit
set, otherwise run with a window of seven (or larger if extended
packet sequence numbering is supported).

If your IP and SVC queues are getting very long, it appears that your
implementation has a flow control problem.  You haven't said anything
about your environment, so I can't comment any more on this area.

Jim