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Re: [DNA-BOF] Draft charter now online



Hi Greg

Thanks for your helpful elaboration. Kindly find my inline comments. 

Greg Daley Wrote: 

> Hi JinHyeock,
> 
> We're talking about two separate concepts here:
> 
> * connection to a single link-instance (isolated subnet),
> 
> * connection to the Internet.

It's not all clear to me why you distinguish them.  

> JinHyeock Choi wrote:
>
> > IMHO, No. To be called connected, I think, you should be able to access 
> > Yahoo at least. :-)   
> > 
> 
> To be connected to Yahoo entails:

Thanks for your helpful elaboration below. 

> 1  Link Layer connection occurs.
> 2  Link-layer authentication is completed

IMHO, Link layer attachment occurs at this point.  

> 3  IP packets can be sent and received.

IMHO, at this stage, a node don't have IP connectivity. IP connectivity is established 
only after, at least, a node has suitable IP address. Even though it is attached to a 
single subnet, it needs a link-local address. Definitely at this stage, a node can't access 
Yahoo. :-). 

This may be a matter of terminology. But we'd better clarify this lest there should 
be confusion. 

> 4  Detection of the new link or router availability

IMHO, we'd better include the detection of the validity of current IP address. While
it is attached to a new link, a node may be able to use its current IP address.  

> 5  Selection of a default router
> 6  Configuration of a topologically correct global address
>      (through DHCP or Stateless autoconfiguration)
> 7  IP ARP/Neighbor Discovery for the default router completes
> 8  Network layer authentication to the router has completed.

IMHO, IP Connectivity occurs at this point or after 10. 

> 9  DNS server is configured
> 10 DNS resolution completes.

IMHO, IP Connectivity occurs at this point or after 8. 

> 11 http traffic is sent and received.
> 
> Which ones do we want to do?
> I'd guess we have to do 4, and maybe hint at
> 5 and 6 (preferably we leave this to the systems
> which already perform these tasks).

IMHO, DNA have to do 4 and 
gather information for 5, 6, 7. 

To do 4, a node should gather information for 5, 6, 7. Usually they are done 
simultaneously. To detect, a node should gather information. In general, a node 
can perform all the above by getting a suitable RA. 

For example, to detect a new router, a node compare the router address in RA 
with its current default router address (For convenience, let's forget link-local scope 
of router address for the while.). If they differ, the one in RA can be used to select 
a new default router. 

> In some cases, we it may be necessary to help to
> start 8, but once again, we're not providing the code
> to do this.

I agree. 

> This above is all about Internet connection.
> 
> I think we have send/receive connectivity at 3 (though
> we may not detect it) until 4.

In here, we have disagreement. This may be the matter of terminology. Let's resolve 
lest there should be confusion. 

> This is sufficient to be connected to the (isolated) subnet.

Even a node is connected to an isolated subnet, I wonder how it can perform ND 
without receiving a suitable RA. 

> If we want to be able to send packets further, this is
> a configuration issue, not a detection issue.

It may not be DNA issue to configure to send packets further. But, IMHO, it's DNA 
issue to gather information for such configuration, for example, the on-link prefixes on a link.   

> I'd prefer we stick to detection that we've got a connection
> to a new subnet or link-instance, and maybe indicate
> (informatively) how we can use the detection to initiate
> configuration.
> 
> Does this make sense?

I think it's impossible to separate detection and information gathering. To detect, a node 
should gather information, which can be used for configuration. 

Best regards

JinHyeock