[Nml-wg] Ports with multiple connections?

[Jeroen van der Ham]

Paola Grosso wrote:
> Your example is not very clear.
> Where does the 'splitting' to to different domains occur: at the Node
> where this port resides, or at the other end of the connection? I mean
> an Ethernet port connects to one other Ethernet port, and if VLAN are
> switched to different domain this occurs within a device (in our case it
> would be handled by a SwitchingMatrix)

I'm sorry, it's a complex situation, and hard to describe. What I meant 
was that the VLAN tagging happens in the node itself, then both VLAN 
sets travel over the same Ethernet port and same cable. Outside of the 
domain this signal gets split, and both VLAN sets head of to their 
separate destination domains.

> At this point you have splitted the vlans and proceed 'normally toward
> the to the two domains (via portC and portD in my example).

What you describe is what I meant with my third possibility, adding a 
virtual node. Yes, this node is there, but its not under the domains 
control, so no control on switching can occur there, other than what is 
configured now. The description you gave may suggest that it is also 
possible to directly switch between ports C and D.

Your description also uses two different adaptations for the separate 
VLAN sets.  AFAIK we haven't decided on how to describe this yet, either 
like this, or with a single adaptations with a possible label set 
attached to it.

Also, this is the possible situation, how do we describe an actual 
configuration?

Jeroen.

PS. This problem, and many others like it is why I would have preferred 
to have a single layer schema first. We're still hammering out the 
details of the basic elements, but already we're opening new cans of 
worms left and right with the problems of describing multi-layer topologies.