Re: [DNA] DNA BCP Submission

[Sathya Narayanan <sathya@research.panasonic.com>]

Dear JinHyeock -

> 
> "An RA with its current active prefix" can't represent a link 
> change 
> properly. Hence, it can't be a link identifier, unless a host 
> adopts CPL
> technique. I am afraid we have a different notion about what link 
> identifier is. 

Arrival of an RA validating the current active prefix or a timeout without such an arrival can not
be used for link change identification? Please correct me if I am wrong here. The timeout value may
be 3 time MaxRtrAdvInterval, but this should still
work.


> We wrote, in "DNA solution framework" draft, 
> 
>   ............................... Each link has its unique Link 
> Identifier and all
>   routers in the link advertise the same Link Identifier in RAs.  

I DISAGREE with the requirement of a 'unique link identifier' agreed among all the routers and the nodes in the link as the ONLY way to do this. The current active prefix in each node is also an acceptable identifier for the link even though it will not be the same in every node and every router. If a node can determine whether its current prefix is supported or not, it has determined link change - it may not be fast but it will still work. Again, I building this argument on my statement above - please correct me if I am wrong.


> What concerns me the most is NOT the draft includes many 
> uncruicial 
> things BUT it doesn't include enough crucial things. Also I am afraid
> that too much focus on uncrucial things may prevent crucial things 
> from getting enough attention.  
This is a valid concern. I agree - as I said earlier
we will take your comments into consideration and improve sections 4,5 & 6 in -02.

> > I don't know if DNA is possible without link identification 
> conceptually 
> > whether or not a unique (for
> > all nodes) 'identifier' is used. See my response below:
> 
> A host may skip to check for link change and directly verify 
> IP configuration one by one. 
I think this is coming back to our disagreement on
the 'uniqueness' of an identifier versus link
identification. Based on Pekka's and your clarification for an ealier email on 'DNA Goals
Issues' from me, my understanding is that DNA
goals is to achieve 'link identification' not necessarily only through the definition of a unique link identifier. By unique, I mean the same identifier in all the node & routers on the link.
Under this understanding, any verification of IP configuration will inherently have a 'identification of the link' component in it.

> 
> The main issue should be whether the draft deals with DNA 
> adequately 
> or not. If so, either way is ok for me about whether to include 
> other 
> stuffs or not. If not, the draft would better work on DNA proper, 
> instead 
> of payint too much attention on secondary stuffs. 

Again, this is a very valid comment. With your input we will try to improve sections 4, 5  & 6 in -02.

thanks & regards,
Sathya