IPv6 news

Tony Li tony.li at tony.li
Sun Oct 16 06:26:20 UTC 2005



>> but when similar things were proposed
>> at other meetings, somebody always said "no! we have to have end- 
>> to-end,
>> and if we'd wanted nat-around-every-net we'd've stuck with IPv4."
>
> Is VJ compression considered a violation of the "end-to-end"  
> principle?
>
> Or perhaps I misunderstand (yet again).


Paul is correct.  Things that looked like NAT were rejected because  
"NAT is evil".  Shifting the NAT to end system removed the objection  
to NAT, tho it's not entirely clear why.  Shifting NAT to the end  
system also happened to simplify the entire solution as well.

VJ compression should not be considered a violation of the "end-to- 
end" principle, as it is a per-link hack and performs a function that  
CANNOT be performed in the end systems.  However, I'm not entirely  
sure that this is relevant.  NAT is not, strictly speaking, a  
violation of the end-to-end principle. It certainly is rather ugly  
and awkward from an architectural perspective, but it is a function  
that is not otherwise required in the end host, so placing it into  
the network does not violate the letter of the principle.  Perhaps  
this is yet another case where people misunderstand the principle  
itself and are invoking it to give a name to their (well placed)  
architectural distaste.

Tony




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