[73708] in North American Network Operators' Group
Re: DNS Anycast as traffic optimizer?
daemon@ATHENA.MIT.EDU (Steve Francis)
Wed Sep 1 14:23:25 2004
Date: Wed, 01 Sep 2004 11:17:13 -0700
From: Steve Francis <sfrancis@fastclick.com>
To: Bill Woodcock <woody@pch.net>
Cc: nanog@merit.edu
In-Reply-To: <Pine.GSO.4.44.0409011103330.28403-100000@paixhost.pch.net>
Errors-To: owner-nanog-outgoing@merit.edu
Bill Woodcock wrote:
> On Wed, 1 Sep 2004, Steve Francis wrote:
> > I'm sure there is research out there...
>
>Why? :-)
>
>
Usual - if I build it myself, will it work well enough, or should I pony
up for a CDN?
> > ...how good/bad using DNS anycast is as a kludgey traffic optimiser?
>
>I'd hardly call it a kludge. It's been standard best-practice for over a
>decade.
>
>
I thought it was standard best practice for availability, like for root
name servers. I thought it was not a good "closest server" selection
mechanism, as you'll be going to the closest server as determined by BGP
- which may have little relationship to the server with lowest RTT.
It'd be nice to see some metrics wither way....
> > THe question is, what is that "some" relationship? 80% as good as
> > Akamai? Terrible?
>
>Should be much higher than Akamai, since that's not what they're
>optimizing for. If you want nearest server, anycast will give you that
>essentially 100% of the time. Akamai tries to get queries to servers that
>have enough available capacity to handle the load. Since they're handling
>bursty, high-bandwidth applications, rather than DNS.
>
> -Bill
>
>
>
>
