[Nml-wg] PerfSONAR UML schema

[Evangelos Chaniotakis]

Hi Freek, everyone.

The short answer is, in the PerfSONAR/IDC schema we're using
Port to refer to a physical interface, and Link to refer to the logical
interfaces running on a Port. The names are slightly misleading,
I guess.

This representation has the advantage of simplifying things, mostly
because broadcast segments and such are not represented as separate
objects; all connections between interfaces are represented by the
point-to-point Link -> remoteLink construct.

Of course this is not the "real" picture of the network, but in practice
this representation does seem to fit the current needs of the PerfSONAR
/ IDC community.



Freek Dijkstra wrote:
> Aaron, Martin,
>
> Thanks for creating the UML schema! It's very useful to start a discussion.
>
> I have two questions.
>
> First, what is the differences between Network and Domain? [1] It was 
> discussed today, but couldn't really understand the details by phone.
>
> Second, the relation Link-Port in PerfSONAR is different from the 
> relation Link-Interface in NDL [2]: in PerfSONAR it is many to one, 
> while in NDL it is one to many. So, I understand that a Port in 
> PerfSONAR can be connected to multiple links, but a link can only have 
> one Port. I don't really understand. Can you give me an example?
>
> In NDL, a Link can have multiple Interfaces (typically 2). An interface 
> is a logical interface, that is only connected to one link. If there 
> would be multiple links, we would describe that with multiple (logical) 
> interfaces (or with a BroadcastSegment).
>
> Regards,
> Freek
>
> [1] The difference between NetworkDomain and AdminDomain in NDL is that 
> a NetworkDomain is a collection of network resources, while an 
> AdminDomain is a collection of people (= an organization!): the people 
> or organization that is responsible for managing the resources. The 
> resources of an AdminDomain are not limited to network resources, but 
> could also include CPU, storage, vizualization, services, etc.
>
> [2] A Link in NDL is a special case of a BroadcastSegment: a broadcast 
> segment with exactly two interfaces.
>