[Nsi-wg] Syntax of NML endpoints in a connection request (was: Determining the Network of an STP)

[Aaron Brown]

On Jul 6, 2012, at 7:14 AM, Freek Dijkstra wrote:

> 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).

The query stuff may have just been shorthand, but in case it's not, overloading the URN to include a query parameter seems a bad idea to me. I'd rather see something like (all in short-hand):

<source>
    <port>
        <port_group idRef="urn:ogf:network:sne.science.uva.nl:2012:lighthouse-egress" />
        <vlan>1791</vlan>
    </port>
</source>

For the "connect any vlan", you could presumably leave the vlan parameter out:

<source>
    <port>
        <port_group idRef="urn:ogf:network:sne.science.uva.nl:2012:lighthouse-egress" />
    </port>
</source>

You could presumably override the set of 'any' VLANs by doing something like:

<source>
    <port>
        <port_group idRef="urn:ogf:network:sne.science.uva.nl:2012:lighthouse-egress">
             <vlans>1790-1800</vlans>
        </port_group>
    </port>
</source>

I'm not positive what the "connect ALL vlans" would look like because I'm not sure what the result of that operation would be. i.e. would it be a port with multiple VLANs, or would it be a PortGroup that functions as a port, or would it be a ridiculous number of ports (depending on how many VLANs are in the PortGroup)?

Cheers,
Aaron

> 
> 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
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ESCC/Internet2 Joint Techs
July 15-19, 2012 - Palo Alto, California
Hosted by Stanford University
http://events.internet2.edu/2012/jt-stanford/

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