Topology layering

Definitions (in search for better terms)

• GNPy-Element (GE): is a physical entity that logically belongs to a NE and physically to a location
• Physical Place is a physical space and describes where the physical entity (GE) can be found. Places can fully contain other places.
• Network Element (NE): a logical entity that is managed together but may has no physical meaning (think of it as the root of a YANG tree)
• NE-Node: A NE can be further grouped into functional entities if needed (YANG subtrees)

Notes:

• a GNPy-element GE is a physical entity and has a hierarchical relationship to location AND to function. This is natural because in order to be considered in a GNPy topology the entity needs to have physical influence on the signal, hence there must be a "location". In order to control the function it must belong to an NE.
• NE and NE-node are only logical/functional groups.
• locations are self contained: a node is either in xor out of a building

There are at least two orthogonal views of the network.

functional/logical

• No geographical/physical locations are tracked at the functional/logical layer.
• "NE" refers to a single managed entity and can be considered a grouping of all functional elements inside the NE. It consists of 1+ GNPy-level elements.
• No matter whether "ROADM" is the complete "switching thingy" or "just a Line degree", it's functionally composed of one or more GNPy-level elements.

GNPy elements: TXPs, Amps, ROADMs (if they cannot be decomposed further), or WSS (future) Reminder: GEs are physical entities AND performing a function. The way they are arranged logically is tracked in the functional/logical view.

physical/geographical

• only geographical/physical places are tracked at this layer. No functional things in this layer.
• only GEs have a Physical place

1. Each individual GNPy element (GE) has a physical place where it can be found.
2. Physical places can be grouped in larger physical groups e.g. buildings --> campus --> city --> country

examples

assume a 2-degree OpenROADM as one NE whereby the two ROADM degrees are located in separate buildings and each degree has booster/pre-amps

• the "OpenROADM" is a network element (NE) because the whole OpenROADM is managed as one entity (this entity has no location!!)
• a ROADM-degree is a NE-node as part of a NE and groups the function of WSS + booster + pre-amp. (this entity has no location!!)
• a WSS, booster, pre-amp are GEs where each has a precise individual location because they are physical entities AND have a logical/functional relationship with a node.

visualisation

functional and physical view can be considered separate but can also be combined in a single view.Assumong a future representation with ROADM decomposed in degrees:

example: show NE function details

• shows NE e.g. as a colored circle
• shows NE-nodes (logical degrees) as colored circles
• shows all GEs belonging to their NE-node in their respective circles

example: show place

• shows place e.g. building as a colored circle
• shows all GEs located in the building

example: show place with NE

• shows place e.g. building as a colored circle
• shows NEs with a component GE in that building a colored circle (note: this circle may extend to other buildings)
• shows all GEs at the intersection of building and NEs