The label type that can be switched is placed in the encoding attribute of the switching service.  For example, in 802.1Q the label type is a VID (or vlan identifier), and of course, the terminology was changed in carrier ethernet so we have STAG and CTAG.  Very lucky for us ;-)

If we use the existing vlan URI we would have something like this:

    <nml:SwitchingService id="urn:ogf:network:example.net:2012:vidSwitchingService"
        encoding="http://schemas.ogf.org/nml/2013/03/ethernet#vlan"
        labelSwapping="true">
        <nml:Relation type="http://schemas.ogf.org/nml/2013/03/base#hasInboundPort">
            <nml:Port id="urn:ogf:network:example.net:2012:nodeA:port_X:1780:in"/>
            <nml:Port id="urn:ogf:network:example.net:2012:nodeA:port_Y:1781:in"/>
        </nml:Relation>
        <nml:Relation type="http://schemas.ogf.org/nml/2013/03/base#hasOutboundPort">
            <nml:Port id="urn:ogf:network:example.net:2012:nodeA:port_X:1780:out"/>
            <nml:Port id="urn:ogf:network:example.net:2012:nodeA:port_Y:1781:out"/>
        </nml:Relation>
    </nml:SwitchingService>

This indicates a switching service that can switch a packet on the 802.1Q VID.

John

On 2013-10-31, at 9:37 AM, Henrik Thostrup Jensen <htj@nordu.net> wrote:

Hi

On Wed, 30 Oct 2013, Jeroen van der Ham wrote:

This is the decision regarding encoding and labeltype that was made for NML:

https://forge.ogf.org/sf/sfmain/do/go/artf6577 :

NML has currently a one-to-one relation between the layer encoding (a URI to define the layer of sublayer of a specific Port of Link) and the label type (a URI to define the resource label of a technology).

Make sense. Thanks for clarifying the difference.

Right now we don't use the encoding in the NSI topology. Is this something we should consider? I am not entirely sure what the benefits are though.

There is not a one-to-one correlation, because encodings (such as Ethernet) still allow traffic without labels at all.

Shouldn't a switching service have an encoding AND a labelType? An ethernet encoding could have both regular and VLAN and carrier ethernet vlan (with q-in-q / s-tag+c-tag), and might only be capable of changing one of them. How would I know which label types can be swapped?


   Best regards, Henrik

Henrik Thostrup Jensen <htj at nordu.net>
Software Developer, NORDUnet

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