Subject: Re: Slow UDP traffic
To: None <tls@rek.tjls.com>
From: Charles M. Hannum <abuse@spamalicious.com>
List: netbsd-users
Date: 06/07/2004 17:52:42
On Monday 07 June 2004 17:37, Thor Lancelot Simon wrote:
> On Mon, Jun 07, 2004 at 12:12:29AM -0400, Perry E. Metzger wrote:
> > Johnny Billquist <bqt@update.uu.se> writes:
> > >> You mean UDP. Initially NFS used UDP, but it turns out that most of
> > >> the time you're better off with a TCP based implementation anyway, and
> > >> almost all modern NFSes do TCP.
> > >
> > > Most NFS implementations can do TCP, but I suspect that most still use
> > > UDP anyway,
> >
> > Not if you want decent performance.
>
> That's not true, unless your path to the fileserver is many hops or your
> local network is very congested.  In my benchmarks, in Jonathan's
> benchmarks and, tellingly, in published SPECsfs runs, for clients on a
> local network UDP with 32K RPCs seems to win -- even with the resulting
> fragmentation.

Relatively modern NFS implementations (like ours) implement TCP-like 
congestion control anyway.