Problems with removing NAT from a network

Frank Bulk frnkblk at
Sat Jan 8 17:22:06 CST 2011

Relay nodes are always protecting themselves by rate-limiting, aren't they?
And isn't most media traffic relayed?  I'm not seeing how the NAT64 scenario
would *dramatically* increase Skype's global relay traffic.  NAT64 would
currently be a very small percentage of all Skype traffic.  

We can always find examples of where things will break with v6.  While the
v6-only world is still very small, let's *start* somewhere, where
intelligent clients like Skype can always "fall back" to v4.  Lots of time
to figure out the corner cases.


-----Original Message-----
From: Matthew Kaufman [mailto:matthew at] 
Sent: Thursday, January 06, 2011 8:55 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?


Skype can still make this work by relaying, 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

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