CGN and CDN (was Re: what about the users re: NAT444 or ?)

Christian de Larrinaga cdel at
Fri Sep 9 16:57:22 UTC 2011

I can predict the response from the teen dens of the world! 
What does CGN mean .. Can't Get Nothing! 


On 9 Sep 2011, at 17:06, Alexander Harrowell wrote:

> On Friday 09 Sep 2011 16:25:35 Valdis.Kletnieks at wrote:
>> On Fri, 09 Sep 2011 11:09:38 EDT, Jean-
> Francois.TremblayING at said:
>>> A very interesting point. In order to save precious CGN resources, 
>>> it would not be surprising to see some ISPs asking CDNs to provide 
>>> a private/non-routed behind-CGN leg for local CDN nodes. 
> The actual problem here is that everyone assumes it'll be donkey's years 
> before every last web server in the world is on IPv6.
> If you're a CDN, though, you can solve this problem for your own network 
> right now by deploying IPv6! Akamai says that you need 650 AS to cover 
> 90% of Internet traffic. I propose that effort getting content networks 
> to go dual stack is better used than effort used to work around NAT444.
> Further, if making your hosting network IPv6 is hard, the answer is 
> surely to give the job to a CDN operator with v6 clue. I actually rather 
> think CDNs are an important way of getting content onto the IPv6 
> Internet.
> In my view CDNing (and its sister, application acceleration) is so 
> important to delivering the heavy video and complex web apps that 
> dominate the modern Internet that this should be a killer. 
> Still, breaking the BBC, Hulu, Level(3), Akamai, Limelight, and Google's 
> video services will probably reduce your transit and backhaul bills 
> significantly. Can't say it'll help with customer retention.
>>> For this to work, the CGN users would probably have a different 
>>> set of DNS servers (arguably also with a private/non-routed
>>> leg) or some other way to differentiate these CGN clients. Lots 
>>> of fun in the future debugging that.
>> Especially once you have 10 or 15 CDNs doing this, all of which have 
> different
>> rules of engagement. "Akamai requires us to do X, Hulu wants Y, Foobar 
> wants Y
>> and specifically NOT-X..." ;)
>> And then Cogent will get into another peering spat and.... :)
> -- 
> The only thing worse than e-mail people who send e-mail 
> to lists complaining about them

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