From owner-freebsd-net@FreeBSD.ORG  Fri Mar 26 11:08:49 2004
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 63DF816A4CE
	for <freebsd-net@freebsd.org>; Fri, 26 Mar 2004 11:08:49 -0800 (PST)
Received: from gate.bitblocks.com (bitblocks.com [209.204.185.216])
	by mx1.FreeBSD.org (Postfix) with ESMTP id A0DCD43D4C
	for <freebsd-net@freebsd.org>; Fri, 26 Mar 2004 11:08:48 -0800 (PST)
	(envelope-from bakul@bitblocks.com)
Received: from bitblocks.com (localhost [127.0.0.1])
	by gate.bitblocks.com (8.12.10/8.12.10) with ESMTP id i2QJ8lHA078562;
	Fri, 26 Mar 2004 11:08:47 -0800 (PST)
	(envelope-from bakul@bitblocks.com)
Message-Id: <200403261908.i2QJ8lHA078562@gate.bitblocks.com>
To: "Marc G. Fournier" <scrappy@hub.org>
In-reply-to: Your message of "Fri, 26 Mar 2004 14:29:56 -0400."
             <20040326141509.G90406@ganymede.hub.org> 
Date: Fri, 26 Mar 2004 11:08:47 -0800
From: Bakul Shah <bakul@BitBlocks.com>
cc: freebsd-net@freebsd.org
Subject: Re: Looking for switch recommendations ... 
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 26 Mar 2004 19:08:49 -0000

> What is the difference between Layer2 and Layer3, and what does that
> affect?

Layer3 == routing (based on IP destination address)
Layer2 == switching (based on enet dest. address)

Layer3 is probably not important for you.

> HP:
> Throughput: 2650 - 10.1 mpps (64-byte packets) 2626 - 6.6 mpps (64-byte packe
> ts)
> Switching capacity: 2650 - 13.6 Gbps 2626 - 9.6 Gbps
> 
> Dell:
> 	Switch Fabric Capacity 8.8 Gb/s
> 	Forwarding Rate 6.5 Mpps
> 
> So, in both cases, the HP  is faster, but ... is that 6.6mpps "per port"
> (ie. the pp?) ... right now, I'm seeing max of around 3Mps going out a
> server, with average being well below 1 ... so I can't see hitting that
> high any time soon ...

For 100Mbps ports, the max packet rate in one direction is
10^8/672 == 148809 pps (packets per sec) per port.  So for 24
port full duplex ports you get an aggregate maximum
throughput of 148809*24*2 = 7738068 = 7.14Mpps (Million pps).
For a 48 port switch it is 14.29Mpps.