Re: Other use cases for header insertion (was Re: Header Insertion and TI-FA)

[Uma Chunduri <[e-mail]>]

Hi Fernando,


On Wed, May 13, 2020 at 9:31 AM Fernando Gont <[e-mail]> wrote:

>
> So you want IPv6, but don't want 40 bytes of overhead.

Yes - an E2E protocol and I know it is not possible. See below..



> Well, I tell you

what: those 40 bytes of overhead *are* IPv6.

I won't disagree.


> That should be an indication that you should probably accept it, do

other smarts to reduce overall overhead,



This is relatively the easier part of the story. And we have already 'n'
(almost) proposal out there.

The one being discussed
https://tools.ietf.org/html/draft-bonica-6man-comp-rtg-hdr-15 and various
other proposals

like https://tools.ietf.org/html/draft-cl-spring-generalized-srv6-np-01,
uSIDs, Tom H's proposal, Greg M's proposal and many more I guess.



> or you might need to look at a

different protocol.



This is where I see a problem overall. There is another protocol which is
similar  and we know the IAB

statement https://www.iab.org/2016/11/07/iab-statement-on-ipv6/. So
practically, we have only one protocol i.e., IPv6.

So, I see you are simply saying it's not possible to have both efficiency
and new requirements in a reasonable way (I know the disagreement on

drafted solutions and the dissent rightfully from some folks)  brought-in
here not only from SRv6 pov, but also from IOAM and early multicast/BIER

 discussions. Given the barrier to change internet STD/8200 (even for a
clarification), we are kind of boxed with the current extensibility
constructs

 it has. Even in one operator domain. I am willing to listen and want to
know your thoughts here. Please don't discount everything as few

additional bytes. The domain I am looking into right now, every additional
byte of overhead  on the packet matters. This may not be big issue in

some other places (where IOAM is sought to be deployed originally i.e.,
inside a DC).


I concur with the point raised in this thread
https://mailarchive.ietf.org/arch/msg/ipv6/0k24SD9iFUW3tmi9EsDAaEPqNi0/

Thank you!
--
Uma C.




>
> I find it amusing to use 128-bit labels for what's pretending to be a

limited domain, and then be concerned about the overhead of the ipv6 header.


> As much as I find amusing to have nodes that claim to support IPv6 (and

hence should be able to ignore a RH that has a SL==0) but they violate

the spec and fail miserably, so then there's a proposal to violate the

spec (PSP) to cope with that.


>
> --

Fernando Gont

SI6 Networks

e-mail: [e-mail]

PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492


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