[100775] in North American Network Operators' Group
Re: cpu needed to NAT 45mbs
daemon@ATHENA.MIT.EDU (Jeff Kell)
Thu Nov 8 15:41:42 2007
Date: Thu, 08 Nov 2007 15:38:09 -0500
From: Jeff Kell <jeff-kell@utc.edu>
To: "Darden, Patrick S." <darden@armc.org>
CC: Carl Karsten <carl@personnelware.com>, nanog@merit.edu
In-Reply-To: <CBE22E5FF427B149A272DD1DDE1075240184E4A9@EX2K3.armc.org>
Errors-To: owner-nanog@merit.edu
Darden, Patrick S. wrote:
>
> From my experience, a fast P4 linux box with 2 good NICs can NAT
> 45Mbps easily. I am NAT/PATing >4,000 desktops with extensive access
> control lists and no speed issues. This isn't over a 45Mb T3--this
> is over 100 Mb Ethernet.
NAT processing requirement thresholds are all about *flows* per second, not *bytes* per second. Once you have a cached flow, it's trivial. The overhead of statefully tracking flows, setup, teardown, timeouts, housecleaning, etc., are the limiting factors.
If you want to stress-test it, you should benchmark it with SQL Slammer :-)
Jeff
