Allow creation of interdomain links

[bcjohnso99]

Use Case 0d (Multi-domain OTN interdomain links discovery (Plug-id based on OTN TTI)) discussed discovery of interdomain links and the attributes in V3.2 section 6.1.5.1 are read only.

For networks where devices or controllers do not support OTN TTI, or in cases where the interface is not OTN and hence does not include overhead for trail trace, a mechanism to create topological relationships between interfaces should be available

[nigel-r-davis]

Interdomain link discovery allows the domain controllers to provide information to the higher controller to allow it to construct a link between domains. The domain controller does not need to understand the interdomain link (we can discuss this).

Where there is no discovery, the domain controller does not need to be informed of an end of an interdomain link. The responsibility rests with the higher controller. Information must be provided to the higher controller to allow it to create the interdomain link (intention). This information perhaps comes from some fiber connection work order or similar.

There are use cases to allow creation and deletion of links in 2.6. This appears to be all that is necessary.

We should discuss this on a call to confirm the understanding here or to trigger the development of further use cases.