[Nml-wg] [Nsi-wg] STPs in NSI v2.0

[Freek Dijkstra]

On 11-07-2012 14:10, Roman Łapacz wrote:

> W dniu 2012-07-10 22:27, Freek Dijkstra pisze:
>>      <nsi:path>
>>          <!-- Two STP, each with a source and sink: a bidirectional path -->
>>          <nsi:STP>
>>              <Network>urn:ogf:network:cesnet.cz:2012:czechlight</Network>
>>              <!-- No VLAN specified: pick any one VLAN within these Port Groups. -->
>>              <source><nml:PortGroup>urn:ogf:network:nordu.net:2012:nordunet-surfnet</nml:PortGroup></source>
>>              <sink><nml:PortGroup>urn:ogf:network:nordu.net:2012:surfnet-nordunet</nml:PortGroup></sink>
>>          </nsi:STP>
>>          <nsi:STP>
>>              <Network>urn:ogf:network:sne.science.uva.nl:2012:lighthouse</Network>
>>              <!-- No VLAN specified: pick any one VLAN within these Port Groups. -->
>>              <source><nml:PortGroup>urn:ogf:network:sne.science.uva.nl:2012:lighthouse-egress</nml:PortGroup></source>
>>              <sink><nml:PortGroup>urn:ogf:network:sne.science.uva.nl:2012:lighthouse-ingress</nml:PortGroup></sink>
>>          </nsi:STP>
>>      </nsi:path>
> 
> Freek, in your examples sent to the NSI group you didn't use idRef
> attribute for nml:GroupPort (or nml:Port). It's a small thing but I
> think we should be strict to use accepted structures. To me using tag
> values for this is not supported by NML at the moment (if we had xsd or
> rnc schema this would be verified easily).

Hi Roman,

That's correct, but the above isn't NML. It is NSI which is referring to
NML objects. Given that NSI does not use id/idRef I decided to use their
syntax.

But you are right that in that case I shouldn't have used the nml
namespace if it is not NML.

What do you suggest?

I can understand the desire to make it a short piece of NML, but that
would require introducing id/idRef, the hasInboundPort/hasOutboundPort
relations, hence the nml:Relation construct. The original proposal used
query parts in the URN, which is not part of NML (I'm not even sure if
the query part is part of the URN or not -- see my mail
http://www.ogf.org/pipermail/nml-wg/2012-July/001012.html).

A further complication was that the NSI in some case want to define a
Port or subset of the PortGroup within a larger PortGroup by identifying
it by its label or label subset, without actually naming the result.
That would require me to introduce unnamed NML objects (NML objects
without a URN identifier, that are identified by their properties). I
may want to do that anyway, but felt this was a bit too much wrestling
if all I wanted was a reference.

But by all means rewrite the examples and propose it to NML + NSI. To me
this is not NML, but you have a valid argument that if this is just
syntactic sugar to define a reference, why not make the sugar look like
the same.

Regards,
Freek