Problems with removing NAT from a network

Fri Jan 7 05:28:34 UTC 2011

> -----Original Message-----
> From: Matthew Kaufman [mailto:matthew at matthew.at]
> Sent: Thursday, January 06, 2011 6:55 PM
> To: Owen DeLong
> Cc: Nanog Operators' Group
> Subject: Re: Problems with removing NAT from a network
> 
> On 1/6/2011 5:48 PM, Owen DeLong wrote:
> > Doesn't all of this become moot if Skype just develops a dual-stack
> capable client
> > and servers?
> >
> Not really. Imagine the case where you're on IPv6 and you can only
> reach
> IPv4 via a NAT64, and there's no progress made on the detection
> problem.
> And your family member is on a Skype-enabled TV plugged into an
> IPv4-only ISP.
> 
> Now you can't get a direct media path between you, even though their
> ISP
> is giving them IPv4 and your ISP is *claiming* you can "still reach the
> IPv4 Internet".
> 
> Skype can still make this work by relaying,

Skype could make it work with direct UDP packets in about 92% of
cases, per Google's published direct-to-direct statistic at
http://code.google.com/apis/talk/libjingle/important_concepts.html

-d


> but in order to protect the
> relay machine's bandwidth it will rate-limit the traffic, and so your
> A/V experience will suffer. And that's assuming there's enough
> dual-stacked relays... if there aren't, it won't be possible to find a
> relay that they can reach over IPv4 and you can reach over IPv6 that
> has
> available bandwidth.
> 
> Matthew Kaufman