[pptp-server] performance tweaks

[Michael Barsalou]

Thanks Charlie!

What I think you just said was:

Use poptop 1.1.2 (which we are)
Out of order packets are caused by internet congestion
Your patch may help (how do I get it?)
MTU/MRU's have no real impact with regard to out-of-order packets

Is this right?

Mike

Date sent:      	Fri, 1 Feb 2002 11:52:06 -0500 (EST)
From:           	Charlie Brady <charlieb at e-smith.com>
To:             	<mjbarsalou at attglobal.net>
Copies to:      	<pptp-server at lists.schulte.org>
Subject:        	Re: [pptp-server] performance tweaks

> 
> On Fri, 1 Feb 2002, Michael Barsalou wrote:
> 
> > What is the current thinking about performance problems.  We are
> > getting lots of out-of-order packets.
> >
> > I looked through the archives and couldn't find any definitive
> > solution or things to try and fix this problem.
> 
> The protocol is broken. It doesn't handle gracefully missing or out of
> order packets. PoPToP 1.1.2 is a big improvement as it makes an effort
> to reshuffle out of order packets.
> 
> PoPToP does not cause out of order packets. They are an unavoidable
> consequence of multiple routing and congestion on the Internet.
> 
> > Here are the things that I believe will help:
> >
> > Setting the mru/mtu to 1450 in the pptpd.conf file
> > removing the speed setting in the pptpd.conf file.
> 
> How would those things help? As far as I can tell the speed setting is
> ignored.
> 
> > Anything else?
> 
> Only ever using PoPToP 1.1.2 is the most important thing that can be
> done.
> 
> Applying my patch and using stateful encryption may help, but at some
> reduction in security. I don't know whether the patch will help or
> not, but it does affect the response of the MPPE encryptor to missing
> or out of order packets. The current PoPToP implementation is not
> compliant with the published protocol - but only for stateful
> encryption, which is little used.
> 
> --
> Charlie Brady                         charlieb at e-smith.com
> Lead Product Developer
> Network Server Solutions Group        http://www.e-smith.com/
> Mitel Networks Corporation            http://www.mitel.com/
> Phone: +1 (613) 368 4376 or 564 8000  Fax: +1 (613) 564 7739
> 
> 




Michael Barsalou
barjunk at attglobal.net