[Nml-wg] Adaptation between Links

[Roman Łapacz]

W dniu 2012-05-10 14:53, Aaron Brown pisze:
>
> On May 10, 2012, at 7:41 AM, Freek Dijkstra wrote:
>
>> I've just created a new artifact,
>> https://forge.ogf.org/sf/go/artf6507
>>
>> Here is the full proposal.
>>
>>
>> Adaptation is between Ports, and requires the following objects:
>> * 2 Link instances
>> * 4 Port instances
>> * 2 Adaptation instances
>> * 8 relations between these instances
>> (see https://forge.ogf.org/sf/go/artf6514 for details)
>>
>> While the above is great to describe a topology in detail, it is
>> sometimes useful to describe less detail.
>>
>> I propose a shortcut to define adaptation between Links:
>>  Link --(providesLink)--> Link
>>
>> This would only require the following objects:
>> * 2 Link instances
>> * 1 relation between these instances
>>
>> This is similar how isSerialCompoundLink also relates Link objects,
>> bypassing the more tedious Link <--(isSink)-- Port --(isSource)--> Link
>> relations.
>>
>> Of course this is less detailed (e.g. it is not possible to describe the
>> type or adaptation, or the name of the Ports). It's intended use is a
>> situations where a full topology description (with all ports) is not
>> required or not desirable.
>>
>> NML:
>>
>>  Link --(providesLink)--> Link
>>
>> The subject (Link on the left) is on the server layer. The link of the
>> right (the object) is one the client layer, and
>> source and sinks of both Links MUST be related with an equal adaptation
>> stack. In other words, both Links MUST span the
>> same distance.
>>
>> For example, in the following ASCII-art, the following statements are 
>> True:
>>  l0 --(providesLink)--> l1     - True
>>  l0 --(providesLink)--> l2-2   - True
>>  l1 --(providesLink)--> l2-2   - True
>> While the following statements are all False:
>>  l0 --(providesLink)--> l3     - False
>>  l1 --(providesLink)--> l3     - False
>>  l2-2 --(providesLink)--> l3   - False
>>
>>                            l3
>>  O -----------------------------------------------> O
>>  |                                                  |
>>  _                                                  _
>>  V                                                  V
>>  |      l2-1              l2-2             l2-3     |
>>  O -------------> O -------------> O -------------> O
>>                   |                |
>>                   _                _
>>                   V                V
>>                   |       l1       |
>>                   O -------------> O
>>                   |                |
>>                   _                _
>>                   V                V
>>                   |       l0       |
>>                   O -------------> O
>>
>> From these requirements follows that the subject is always a terminated
>> network connection (thus not a segment of a
>> larger link connections), while the object is never a serial compound 
>> link.
>>
>> XML example:
>>
>> <nml:Link
>> id="urn:ogf:network:example.net:2012:link:fiber:NOR:xe-1-1-0:AMS:xe-2-1-0:1530nm">
>> <nml:name>1530nm wave between NOR and AMS</nml:name>
>> <nml:Relation type="providesLink">
>> <nml:Port
>> idRef="urn:ogf:network:example.net:2012:link:eth:NOR-AMS-0001" />
>
> Should this be <nml:Link> and not <nml:Port> ?


> If not, I'm apparently missing something obvious. If so, I'm fine with 
> the proposal.

providesLink may not be obvious for people who will want to use NML that 
it is  adaptation. Of course a detailed documentation of it may solve 
the problem but on the other hand such things should be intuitive. Maybe 
still using nml:Service element,  only with type attribute and no 
additional info, would be better?

Roman

>
> Cheers,
> Aaron
>
>> </nml:Relation>
>> </nml:Service>
>>
>> RDF example:
>>
>>  @prefix nml: <http://example.ogf.org/schemas/nml/>; .
>>  @prefix nmlrel: <http://example.ogf.org/schemas/nml-relation/>; .
>>  @prefix ex: <urn:ogf:network:example.net:2012> .
>>
>>  ex:link:fiber:NOR:xe-1-1-0:AMS:xe-2-1-0:1530nm a nml:Link ;
>>    nml:name "1530nm wave between NOR and AMS" ;
>>    nmlrel:providesLink ex:link:eth:NOR-AMS-0001 .
>> _______________________________________________
>> nml-wg mailing list
>> nml-wg at ogf.org <mailto:nml-wg at ogf.org>
>> https://www.ogf.org/mailman/listinfo/nml-wg
>
> Internet2 Spring Member Meeting
> April 22-25, 2012 - Arlington, Virginia
> http://events.internet2.edu/2012/spring-mm/
>
>
>
> _______________________________________________
> nml-wg mailing list
> nml-wg at ogf.org
> https://www.ogf.org/mailman/listinfo/nml-wg

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.ogf.org/pipermail/nml-wg/attachments/20120510/16a97134/attachment.html>