Re: [Int-area] New Version Notification for draft-herbert-ipv4-eh-03.txt

["[e-mail]" <[e-mail]>]

<Joe>
> 
>> You’ve just described a transport protocol that the intermediate nodes know.
> 
> 
> Joe,
> 
> A transport protocol doesn't meet the requirements. They don't work with any transport protocol other than themselves,

They do when you define them that way, i.e., “here’s a transport protocol header A, after which you can use any transport protocol, as indicated in field X”.

> and intermediate nodes cannot robustly parse transport headers 

They can’t parse these either. But, if upgraded to do so for headers “A”, as per above.

> This has to be L3 protocol.

It’s not. It’s L4, or at least that’s what it is* to IP.

IPv6 can call them extensions because all IPv6 nodes already know what to do with them, even for codepoints they’ve never seen. IPv4 implementations have no knowledge of this new transport protocol - only those who have been upgraded.

No different in principle - or implementation - than DCCP or SCTP.
No easier to deploy.
No more unique utility, IMO.

Joe

*All protocol layers are relative, so you COULD do the following:

	IPa IPb UDPc UDPd

To IPa, its view of itself is layer 3, IPb is layer 4, not an extension to layer 3.

To IPb, its view of itself is layer 3, IPa is layer 2 and UDPc is layer 4.