Hi Freek- Regarding the "connectedTo" or "mapsTo" terms in the NSI topology, those could be different strings if NML is already using them in a different sense. We could in NSI use the term "sharesInterfaceWith" or "internallyTranslatesTo" for each of those respectively. THis ould be a minor change for us. More important to NSI is that there be the /semantics/ that those relations represent. On a slightly different issue - I saw a comment somewhere (maybe the minutes of THursday's call?) that said NSI was not using the SDP relations... This is wrong. NSI very much uses SDPs in the current topology. SDPs are represented within an STP object with a "connectedTo" relation referencing another STP object. Here is a OWL snippet: <owl:NamedIndividual rdf:about="urn:ogf:network:stp:northernlight.ets:poz-1"> <rdf:type rdf:resource="http://www.glif.is/working-groups/tech/dtox#STP"/> <connectedTo rdf:resource="urn:ogf:network:stp:pionier.ets:cphb"/> </owl:NamedIndividual> In this snippet, NorthernLight STP "poz-1" is in an SDP relationship with the Pionier STP "cphb". The Snippet is the STP object defined for NothernLight. A mirror image STP is defined in Pionier. Thus a path finder traversing the networks in either direction will easily see the SDP relation. There may be better ways to represent the SDP, this was what we did for the fall...We can discuss others... The NSI topological _/representation/_ (i.e. the OWL/RDF form) could take other forms that we currently have as long as the semantics of the three key NSI objects are preserved: NSI Networks (service domains), STPs (edge ports/points), and SDPs (adjacencies). These are I think represented in NML, though there is probably a different notion of "link" vs "SDP" that we need to reconcile...and maybe some of the mechanics of the "port" vs "STP" ... These notions are very close. Jerry On 2/16/12 10:57 AM, Freek Dijkstra wrote:
A somewhat related issue on source/sink. I don't think this was ever written down.
Freek Dijkstra wrote:
The question at hand is basically how to describe the following (with apologies with my poor ASCII art skills)
port A link X port B link Y port C O------------------>O------------------>O
[...]
In the NML schema it is currently defined as:
link X relation=source port A relation=sink port B link Y relation=source port B relation=sink port C For the record, an alternative way to describe this is making the ports leading instead of the links:
port A relation=egress link X port B relation=ingress link X relation=egress link Y port C relation=ingress link Y
Technically I think these are equivalent: the provide a directed relation between links and ports. Which one is syntactically better depends what is more common, a one-to-many or a many-to-one relation between ports and links.
For the circuits, this is often a one-to-one relation. Since we implemented cross-connects as links, VLANs are likely also described as some kind of "link", but one with multiple sources and sinks. Hence, there is a one to many relation from link to port. This means that the source and sink relation we have now is more easy to convey in XML than the alternative ingress and egress relation.
I personally think the source/sink stuff is still the best alternative we have.
Regards, Freek _______________________________________________ nml-wg mailing list nml-wg@ogf.org https://www.ogf.org/mailman/listinfo/nml-wg