John MacAuley wrote:
Just trying to understand how these different proposals come together.
Here is a more realistic NSI sample (namespaces are left out of simplicity, and I just made up some NSI names, as I'm not familiar with the NSI syntax):
<connectionrequest> .... <endpoints> <endpoint> <Topology>urn:ogf:network:nordu.net:2012:org</Topology> <source>urn:ogf:network:nordu.net:2012:onsala-tx?vlan=1791</source> <sink>urn:ogf:network:nordu.net:2012:onsala-rx?vlan=1791</sink> </endpoint> <endpoint> <Topology>urn:ogf:network:sne.science.uva.nl:2012:org</Topology> <source>urn:ogf:network:sne.science.uva.nl:2012:lighthouse-egress?vlan=1791</source> <sink>urn:ogf:network:sne.science.uva.nl:2012:lighthouse-ingress?vlan=1791</sink> </endpoint> </endpoints> .... </connectionrequest>
This syntax allows multipoint-to-multipoint connections, if desired. The nml:Topology tells the recipient in what NSAnetwork the endpoint is located. NML is unidirectional, and the explicit source and sink makes sure the direction is unambiguous. These sources and sinks contain URNs of a PortGroup, with a query part added ("?vlan=1791") that uniquely identifies a single Port within the PortGroup. It is also possible to use a URN that just defines a Port directly (without the query part). I can imagine that a NSI requester does not care about the specific VLAN that is chosen, and likes to say "just pick any VLAN in this PortGroup". How exactly that is done, and how to distinguish it from "please connect ALL VLANs in this PortGroup" is an open question for NSI to answer. Regards, Freek