[Nml-wg] Definitions of "Adaptation", "AdaptationType" and "AdaptationService"

[Freek Dijkstra]

Hi John,

Great to hear from you.

> Some clarifying questions inline --

Some hopefully-not-too-mystifying answers below.

>> * AdaptationService: Adaptation capability in a topology or node.

John:
> I would think this could happen in a port, or at least be specific to  
> a port.  Is that possible?

It certainly can be specific to a port. We introduced the concept of
PortGroup to handle the case where only a subset of the Ports in a
device can handle some Adaptation.

What do you mean with "in a port"? In our proposal, a Port is a
*logical* entity, so adaptation happens between Ports. In your question
and my sentence above, we refer to Port as a physical Port in a Node
(which may have multiple logcial Ports). Would it be useful to introduce
another term to distinguish between the two concepts?

>> * Layer: A collection of Ports with common Characteristic Information
>> (Characteristic Information is defined in ITU-T G800; we envision
>> sublayers to be a separate layer too, but this is really up to
>> technology-specific extensions).

> can you define sublayer?  Is this multiplexing within a layer using  
> labels to encapsulate the sublayer?  Or something else?

Our proposal does not distinguish between layer and sublayer. Do you
need this distinction?

> When  a link with multiple labeled sub-links connects to a port with  
> multiple labeled subports on a node --
> What is the way that labeled links are concatenated to labeled ports  
> -- is that cross connect?  If not, what is it?

I'm not entirely sure if I follow you here. Concatenation of labeled
subports in a port (which may or may not be connected to a link) seems
multiplexing to me. A I would describe a cross-connect (with these
terms) as the connection between a labeled subport in one port and a
labeled subport in another port.

However, this is all speculation on my side: we have not defined
subports or labels.

In fact, you have a good point with label: our current proposal does not
discuss multiplexing (or inverse multiplexing), although we certainly
intend to support that. In my view, labels are used for two specific
purposes:
1) To distinguish between channels in a link (multiplexing)
2) To switch data in a Node (cross connects)

>From your NSI work, I presume you are mostly interested in describing
multiplexing. Are you interested to create a proposal for NML to cover
this one or both of these topics (multiplexing and/or cross connects)?
If so, I offer you my help.

Regards,
Freek