"All models are wrong, but some are useful"
wikipedia
— George E. P. Box
Inspired by Google's Multi-Abstraction-Layer Topology (MALT; see NSDI 2020 site for paper, slides, and recorded presentation), this collection of protobuf definitions and supporting code aims to make feasible richer communications network modeling of time-dynamic elements.
As in the MALT paper, this is an Entity-Relationship system where each have "kinds" but only Entities have attributes.
The primary purpose of this data model is to support constructing a graph of a network with its temporo-spatial dynamic aspects suitable for:
- evaluating whether and how a requested service might be built atop the network, and
- issuing instructions to selected elements necessary to enact the service.
In other words, this data model is in service of a Network Digital Twin of the style depicted in draft-irtf-nmrg-network-digital-twin-arch:
+---------------------------------------------------------+
| +-------+ +-------+ +-------+ |
| | App 1 | | App 2 | ... | App n | Application|
| +-------+ +-------+ +-------+ |
+-------------^-------------------+-----------------------+
|Capability Exposure| Intent Input
| |
+-------------+-------------------v-----------------------+
| Instance of Digital Twin Network |
| +--------+ +------------------------+ +--------+ |
| | | | Service Mapping Models | | | |
| | | | +------------------+ | | | |
| | Data +---> |Functional Models | +---> Digital| |
| | Repo- | | +-----+-----^------+ | | Twin | |
| | sitory | | | | | | Network| |
| | | | +-----v-----+------+ | | Mgmt | |
| | <---+ | Basic Models | <---+ | |
| | | | +------------------+ | | | |
| +--------+ +------------------------+ +--------+ |
+--------^----------------------------+-------------------+
| |
| data collection | control
+--------+----------------------------v-------------------+
| Real Network |
| |
+---------------------------------------------------------+
Figure 2: Reference Architecture of Digital Twin Network
It aims to facilitate use by an SDN Controller.