1. NML-WG: Monday brainstorming
NML-WG discussion
NML-WG: Monday brainstorming

2. NML-WG: Monday brainstorming
Schema usecases
Expecting from NML schema (usecases):
Path finding;
Monitoring;
Allows inter and intra domain network descriptions (inter domain comes from extracting information from the intra domain) ==> varying resolution of schema
Maps creation.
Dynamic behavior of networks (new circuits,shotlived services) are representable.
Validate this against usecases already described in Deliverable 1.
NML-WG: Monday brainstorming

3. NML-WG: Monday brainstorming
Classes requirements
Requirements (from DCN and G-Lambda) in class definition:
URI as domain identifiers and global naming mechanism;
Links: need description of (or deriving from description) multiplexing, sub-links;
Circuits/paths: need to describe the end-to-end path (from src to dst) and their characteristics;
Concept of adaptation;
Hierarchy of (logical) links. Nesting of links.
NML-WG: Monday brainstorming

4. UML diagrams comparison
Basic classes are further extended by using Layer information:
PerfSONAR basic classes:
Domain Node Port Link Path Network Service Location
NDL basic classes:
Administrative_domain Network_domain Device Interface Link Location Service
cNIS basic classes:
(generic) Node Link Interface Location. (Concept of basic class grouping to allow description of domains, networks, etc)
NML-WG: Monday brainstorming

5. NML-WG: Monday brainstorming
Common classes
Core ontological classes (ontological constructs):
Group
Node/Device
Interface/Port
Link
Service
Common ontological classes:
- Location
- Name
Identifier
NML-WG: Monday brainstorming

6. NML-WG: Monday brainstorming
Group
Group = abstract type that becomes specialized depending on elements we put it.
Ordered and unordered group:
General Path (a specialized ordered group): ***
Link path:
Domain path:
Loose path:
Domain (a specialized unordered group):
Network domain
Administrative domain
VLAN domain
Device (a specialized unordered group of Interfaces)
*** do we want to keep Path in here (as it is the only type of ordered group we can think about) or should be moved out of Group (only unordered)
NML-WG: Monday brainstorming

7. NML-WG: Monday brainstorming
Node/device
Node: ***
*** Extension of this class with layer-specific information might follow (layer1, layer2, layer3 node ….)
*** ’Modern’ nodes/devices span multiple layers. How do we model those?
*** Do we need the concept of switching matrix in here?
NML-WG: Monday brainstorming

8. NML-WG: Monday brainstorming
Interface/port
Interface/port: ***
Every interface belongs to a node (for inter-domain links the far end node may be unknown, and the far-end interface might be just partially specified)
Layer1 interface
Fiber interface
OTN interface ….
Layer2 interface
SONET interface
Ethernet interface
…..
Layer3 interface
IPv4 interface
*** Are technology-specific interfaces (I.e Ethernet interface) subclasses of the layer interfaces (I.e. Layer2 interface) or subclasses of the generic interface?
NML-WG: Monday brainstorming

9. NML-WG: Monday brainstorming
Link
Link:
composed of two interfaces (start and end); a physical Link goes between two physical interfaces, a logical link goes between logical interfaces;
links are unidirectional;
links can/are hierarchically organized (a layer3 link could be carried over the sum of one or more layer 2 links) ***
concept of link aggregation (serial links and parallel links)
can be recursive
*** how do Links and Paths (Link paths) relate to each other? Is the first a physical object and the second a logical object?
NML-WG: Monday brainstorming

10. NML-WG: Monday brainstorming
Link: more on this…
Link:
Logical link (two logical interfaces)
Physical link (two physical interfaces)
Circuit
NML-WG: Monday brainstorming

11. NML-WG: Monday brainstorming
Location
Location:
- Describe a physical point in space (by using geo-coords, street names ….)
- A Node is one Location at the time, Links can pass through multiple Locations (I.e. they go through an ordered group of geo-coords)
NML-WG: Monday brainstorming

12. NML-WG: Monday brainstorming
Service
Service: ***
Application service
Network service
Information service
…..
*** Are services offered at a Domain level (with Domain being a Group of Nodes) or by a Node or an Interface directly? What is the distinction between a Service and a capability?
*** Are Adaptations and Switching Matrixes type of services?
NML-WG: Monday brainstorming

13. NML-WG: Monday brainstorming
Further suggestions
Suggestion from John V.
Introduce the concept of Circuit in addition to Path and Link.
The Path is the sequence of Links you are going over; the Circuit is the part of a Path you are going over.
NML-WG: Monday brainstorming

14. NML-WG: Monday brainstorming
Common relationships
How the classes related to each other: concept of one-to-one, one-to-many and many-to-one, any-to-any.
Comprises, composed of, …are relationship blocks.
One to one:
One-to-many:
Many-to many:
Any-to-any:
‘self recursive’ and ‘composed of’.
Are these are two distinguished ideas?
self recursive is not a group; composed of represents a many to many relationship and is described by a group.
NML-WG: Monday brainstorming

15. NML-WG: Monday brainstorming
Next steps
Definition of basic NML-WG schema classes and attributes (Done preliminary work)
Outcome of ontology discussion during OGF22 will go in the first draft of Deliverable#2 (Paola)
Further group discussion via .
Provide definition of URIs/namespaces
Validation against existing usecases
Will wait for a ‘consolidated’ draft of deliverable #2
Which tools we will use to actually produce/write/develop the schema?
UML diagrams
MagicDraw
Eclipse UML modeling tool: EMF (Eclipse Modeling Framework) <- preferred (needs investigation)
RDF and XML as exchange formats: translations tools between the two. Best practice representation in RDF and XML of the basic ontologies. Adopters are free to choose other syntaxes as they wish.
NML-WG: Monday brainstorming

16. NML-WG: Monday brainstorming
Timelines
Reverse timeline:
June 08 - OGF23 - meeting in Barcelona. Two sessions, plus round-the-table discussions all day.
May Usecases validation - All
March/April/May 08 - Further schema work. 1rst step is draft document (Paola)
March 08 - Finalize Deliverable #1.
NML-WG: Monday brainstorming