[Nml-wg] More UML....

[Martin Swany]

Hi Freek, All,

>> Would it make sense to make a cross-connect a subclass of link?
>
> That is what we had at first. I think we changed because we sometimes
> want to explicitly say something really is a link, not a cross  
> connect.
> If a cross connect is a subclass of a link, you can not do so.
>
> We briefly played with the notion of having a abstract class called
> "relation", of which both link, cross-connect and adaptation are  
> subclasses.

I don't think that we were considering "link" to be a subclass of  
"relation".
I believe that we were considering that what you're referring to as  
"adaptation"
is sometimes a simple relation (a Layer 3 interface atop a Layer 2  
interface)
and sometimes an active "Service/Function".

My perspective is that a cross-connect is a role/type of "link", that a
an active adaptation is a "Function/Service" of type adaptation and
that a L3 port atop an L2 port is a "relation".

best,
martin