RE: RE: High Speed Firewalls

[Ryan Russell <ryan () securityfocus com>]

On Mon, 20 Mar 2000, David Newman wrote:

> > That has mostly to do with things like round-trip delays for handshakes,
> > and TCP slow start.  If you take a sample out of the middle of such a
> > connection, for a much longer file, it will look better.
> >
> > I think at some point, your constraining factor might get to be
> > latency.  The window size can only get to be 64K, right?
> >
> >                             Ryan
>
> Er, sorry to have to go through this again. This has nothing to do with
> latency (delay) or window size. On the wire, user data (like the contents of
> a file) is wrapped in packets. Packets have headers. Headers add overhead.
> Ergo, it's not possible to put 100 Mbits of *user data* on the wire in one
> second. Ergo, "wire-speed throughput" from an application perspective is a
> myth.
>
> Please reread the earlier thread -- this has been all been hashed over,
> several times.

Wire-speed throughput is the theoretical maximum throughput including
headers, etc..

Were it not for latency, the extra delay due to headers and such (using
maxium-size packets) would be about 0.0001 seconds.  

                                        Ryan