[119161] in North American Network Operators' Group
Re: What DNS Is Not
daemon@ATHENA.MIT.EDU (David Andersen)
Sun Nov 8 19:43:06 2009
From: David Andersen <dga@cs.cmu.edu>
In-Reply-To: <20091109003028.GD10998@vacation.karoshi.com.>
Date: Sun, 8 Nov 2009 19:42:18 -0500
To: bmanning@vacation.karoshi.com
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Nov 8, 2009, at 7:30 PM, bmanning@vacation.karoshi.com wrote:
> On Sun, Nov 08, 2009 at 07:17:16PM -0500, David Andersen wrote:
>>
>> "Our trace-driven simulations yield two findings. First, reducing the
>
> -----------
>> -Dave
>>
>
> a simulation is driven from a mathmatical model, not real world
> constructions.
Hi, Bill -
The paper is worth reading.
"The paper also presents the results of trace-driven simulations that
explore the effect of varying TTLs and varying degrees of cache
sharing on DNS cache hit rates. "
emphasis on *trace-driven*. Now, you can argue whether or not their
traces are representative (whatever that means) -- they used client
DNS and TCP connection traces from MIT and KAIST, so it definitely has
a .edu bias, iff there is a bias in DNS traffic for universities vs.
"the real world", but to the extent that their traces represent what
other groups of users might see, their evaluation seems accurate.
-Dave
