Support wavelength tuning constraints

[aguoietf]

The model can consider to support the following wavelength tuning constraints:

• Use the same wavelength between working, protection and restoration path
• Allow/disallow the use of regenerators (in working or protection or both)
• Allow/disallow wavelength changes along the path (in working or protection or both)
• path optimization objectives, e.g.
  • optimize on TE cost and only validate if path is optically feasible
  • optimize on optical performance, e.g. best OSNR
  • specify wavelength tunning range allowed on a transceiver, e.g.
  • allow tuning in 100Ghz grid even if the transceiver supports 50Ghz
  • allow c-band only or full super-c band tuning
  • (these may be done by using the label restriction from the base model but is a bit cumbersome)

[aguoietf]

We need to add a TE metric (optical feasibility) to the list of TE tunnel criteria to be considered.