Subject: Re: NFS/RPC and server clusters
To: <>
From: David Laight <>
List: tech-net
Date: 10/16/2003 15:43:49
On Thu, Oct 16, 2003 at 07:44:50AM -0400, William Allen Simpson wrote:
> David Laight wrote:
> > 
> > > > If a system sends a large TCP message it will go out as back to back
> > > > ethernet frames.
> > >
> > > To a max of 4 segments, assuming following RFC recommendations.
> > 
> > Why? a full window of TCP data will be sent (at least once the window
> > has opened).  The ethernet card will just shovel them out.
> > 
> The algorithms have been floating around and well documented for years.
> I'd assumed NetBSD was up-to-date.  Most recently, RFC-2581 and RFC-3390 
> (just checked).

I was talking about what happens once the 'slow start' time has finished,
and the full window is being transmitted.  The slow start stuff shouldn't
stop the full window being used even under these conditions.

No matter what, using UDP saves you having to transmit any TCP acks.

FWIW the tests I was talking about were done before NetBSD existed.
But are relevant because they are a 'feature' of CSMACD.


David Laight: