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

[Jeroen van der Ham]

On 28/01/2010 21:16, John Vollbrecht wrote:
> Thanks Jeroen -
>
> I include Freek -- perhaps this should go the the list?
>
> additional questions below --
>
> On Jan 28, 2010, at 4:58 AM, Jeroen van der Ham wrote:
>
>> On 27/01/2010 18:52, John Vollbrecht wrote:
>>>> * AdaptationType: Abstract type describing the technology of embedding
>>>> the data of one layer into the data of another layer.
>>>> * AdaptationService: Adaptation capability in a topology or node.
>> >
>>> I would think this could happen in a port, or at least be specific to
>>> a port. Is that possible?
>>
>> The AdaptationService is indeed specific to a port, as we define
>> later. However, often in a Node there are a group of ports with the
>> same AdaptationService, i.e. the capability of adapting one layer into
>> another.
>> We feel that without loss of generality you can state that an
>> AdaptationService exists between a group of (logical) ports, and
>> another group of (logical) ports, instead of specifying this for each
>> of the ports individually.
>>
> this seems fine -- I tend to think that a generic connection at some
> level (e.g. ethernet) might be carried internally in a provider as
> VLAN/Ethernet and perhaps delivered as ethernet/ MPLS for example. In
> that case the generic connection is adapted to VLAN/ MPLS, then to
> ethernet/MPLS. So adaptation is at a port, not between them.

The idea is that the adaptation takes place in a physical port, but we 
model it using two logical ports.

>
>>> 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?
>>
>> Labeled links are directly associated with labeled (logical) ports.
>>
>> Multiplexing and Demultiplexing could then be necessary to describe
>> this properly, cross-connect and all. However, we haven't defined that
>> yet.
>>
> so there is a port on a node. but if a topology edge is the end of a
> link, what is that called? do the ends of links have names? I have
> started thinking they should have names (like ITU, they have ports
> perhaps), and where two ports connect is a point.
>
> I understand this is not defined yet - and of course this is the basic
> thing that a lot so NSI is concerned with. Which is ok -- just need to
> be clear.

I am not sure yet whether Link-ends will have names.
We currently have Link objects, describing unidirectional links, with a 
source and a sink relation, so names for the ends may not be necessary.

Jeroen.