[Nsi-wg] NML topology

[Guy Roberts]

Freek,

Some interesting questions, here are my thoughts your questions-

Requirement 1:  In my opinion each network resource should be owned by only one NSA.  However, one NSA can own many resources.  I guess this means that 'owned' and 'controlled' are synonymous.  Though perhaps the distinction could be that a passive object (eg patchcord link) can only be owned and not managed?

Requirement 10:  We need to be clear about the difference between a 'Path' and 'Connection'.  According to NSI terminology (the current NSI terminology will be presented on the Wednesday call) a Connection is the conduit that transfers bits.  A 'Path' is the output of the path computation and is a directed list of routing objects (say ports), this may be a complete list or a minimum list which only includes end ports. It is possible that a 'Path' could include routing objects like intermediate networks.  So in my mind, a Path should be made up of existing NML resources, such as ports, links etc.  At this stage, I don't know that any new network definitions are necessary to describe a Path.

Guy


-----Original Message-----
From: Freek Dijkstra [mailto:Freek.Dijkstra at sara.nl] 
Sent: 22 February 2010 16:34
To: Guy Roberts
Cc: NSI WG; Jeroen van der Ham; John Vollbrecht
Subject: Re: [Nsi-wg] NML topology

Hi Guy,

Thanks a lot! With a list like this we can take it to the NML and see
how this applies to our current ideas.

I highly encourage your distinction between requirement and solution.

Two questions (more will pop up later):


> Requirement 1: The model should be able to describe a grouping of
> network resources that are owned and controlled by a single provider
> or NSA. (I will call this a NETWORK for the moment)
> Requirement 2: The model should be able to describe a grouping of
> NETWORKs. (e.g. a federation of providers with shared policy)

I understand the word "controlled". What do you mean with "owned"? The
entity that decides on the policy? Is that always the same as the
controller, or is there a 1:many, many:1 or many:many relation between
"owner" and "controller", or is there no requirement for this.

> Requirement 10: The model should be able to fully describe a circuit
> (i.e. NSI service) that transits the topology.

Does this mean we only need to describe the full circuit with all
details (all device and links along the way), or is it also required to
describe a circuit without details (either just the end nodes, the loose
hops, the internetwork links, ...).

Also a general question: Is a NSI circuit single layer, or is it also
required to specify different layers? (Perhaps this last is more a
question for NML).

Regards,
Freek