Session Date/Time: 07 Nov 2022 09:30

nmrg

Summary

The NMRG session covered a range of active research topics, including progress on Intent-Based Networking (IBN) use cases, ongoing discussions around Artificial Intelligence (AI) for network management, the concept of Network Digital Twins, green networking challenges, and fundamental issues in modeling language boundaries. Key discussions revolved around the potential for merging related IBN use case drafts, determining the NMRG's role in AI and green networking research, and refining the scope and architecture of digital twin concepts.

Key Discussion Points

Chairs' Introduction and Status Update:
- RFCs 9315 (IBN Networking Concept and Definition) and 9316 (Intent Classification) have been published.
- draft-irtf-nmrg-network-digital-twin-architecture is an active research group document.
- Potential upcoming calls for adoption for draft-irtf-nmrg-network-measurement-intent, draft-irtf-nmrg-network-slice-intent, and draft-irtf-nmrg-interconnection-intent.
- A question was raised on whether to consolidate multiple IBN use cases into a single document.
- New research areas like AI in networking and green networking were highlighted, prompting a discussion on their fit within NMRG.
Network Slice Intent Use Case (draft-irtf-nmrg-network-slice-intent):
- Presented by Luis. Objective: leverage IBN for requesting IETF network slices, complementing existing slice work.
- Updates include an "Assurance Phase" for monitoring, aggregation, validation, and reporting, forming inner and outer control loops.
- A Proof of Concept (POC) is targeted, focusing on translation from upper systems (e.g., 3GPP) to NBI/YANG models, leveraging existing drafts.
- Discussion points: Distinction between SLO/SLE in intent formulation vs. translation, the balance between research and standardization aspects (translation may not be research, but service/network SLO mapping is), and interaction with TM Forum APIs.
Interconnection Intent Use Case (draft-irtf-nmrg-interconnection-intent):
- Presented by Luis. Objective: move beyond classical IP traffic interchange to include service functions and compute resources in interconnections using IBN.
- Use cases include non-public to public networks in 5G, multi-domain service requests.
- Updates include an "Assurance Phase" and insights into interconnection structure (data traffic types, service functions, resources, constraints).
- A POC, potentially a hackathon topic, is envisioned for IETF 118.
- Discussion: Expand scope to include client-to-provider interconnection (beyond provider-to-provider). A key question was posed to the chairs and the research group regarding merging this document with the Network Measurement Intent draft due to common interests.
Network Measurement Intent (NMI) (draft-irtf-nmrg-network-measurement-intent):
- Presented by Dan Yang. Objective: use NMI for network performance aggregation and validation against intent.
- Updates clarify relationship with published IBN RFCs. NMI is divided into time/spatial accuracy and static/dynamic NMI.
- Nine members supported adoption.
- Discussion: Similar to interconnection intent, the question of merging NMI with other IBN use cases was raised, emphasizing the need to identify a common structure and template first.
Research Challenges in AI for Network Management (draft-irtf-nmrg-challenges-ai-nm):
- Presented by Jean-Francois. Objective: classify challenges related to AI techniques, network data, and AI acceptability in network management.
- Updates: Covered data mesh concept, addressing challenges of data granularity, volume, and alignment.
- Discussion: Suggestions to include suitability of unsupervised learning and the critical role of distributed AI (e.g., Federated AI) and knowledge sharing. A call for volunteers to contribute to the distributed AI section was made.
Consideration of Deploying AI Services in a Distributed Approach (draft-irtf-nmrg-distributed-ai-services):
- Presented by Won. Objective: investigate the development of AI services, specifically focusing on AI inference (prediction) rather than training.
- Updates: Reconfigured Section 4 to cover functional characteristics of hardware, AI models, and communication methods, citing an ETSI document.
- Motivation: Discussed trade-offs between model accuracy, size, inference time, and device capacity (local, edge, cloud).
- Discussion: Questioned the focus (system vs. network management); suggested expanding to include network-specific challenges like deployment of federated learning and horizontal distribution of AI jobs. The possibility of merging with the AI challenges document was also raised.
Performance Oriented Digital Twins (PODT) (draft-irtf-nmrg-performance-digital-twin):
- Presented by Chris. Objective: generalize the concept of a performance digital twin to include Optical Performance Digital Twins (OPDT) alongside Network Digital Twins (NDT).
- Introduced Network Information Interface (NII) for absorbing physical network data and Digital Twin Interface (DTI) for scenario definition.
- Use cases: Optical services planning, network planning, reprovisioning, risk mapping.
- Discussion: Differentiated between an "information digital twin" (providing data) and a broader "action digital twin" (ingesting intent, issuing control), noting the latter approaches a full management plane. Also, questions on traffic pattern twins (covered in previous NDT draft) and configuration interaction.
Requirements for Interfaces of Network Digital Twin (draft-irtf-nmrg-dt-interfaces-requirements):
- Presented by Daniel. Objective: define requirements for the Northbound, Internal, and Southbound interfaces of a Digital Twin Network (DTN).
- Requirements for Northbound: openness, scalability, portability, flexible deployment.
- Requirements for Internal: united data format, adaptability, portability of data models, flexibility/extensibility.
- Requirements for Southbound: information interaction, real-time, compatibility.
- New draft, feedback requested.
Challenges and Opportunities in Green Networking (draft-irtf-nmrg-green-networking-challenges):
- Presented by Alex. Objective: analyze challenges and opportunities for reducing carbon footprint in networking.
- Updates: Emphasized energy sources, manufacturing life cycle, and protocol optimization, beyond just energy usage efficiency.
- Identified four aspects: device/equipment level (visibility, metrics), network level (green routing, resource saving, abstractions), protocols (fast discovery, reconversion), and architecture level (CDN/ICN optimization).
- Discussion: Strong support for the urgency of the work (no longer "nice-to-have" but critical for future deployments). Emphasized the need to integrate energy considerations as a new dimension in network management and policies, balancing with other goals like resilience and service levels. Suggested exploring normalization of metrics for power consumption.
Modeling Boundaries and its Boundaries in Modeling Languages (draft-farrell-nmrg-model-boundaries):
- Presented by Nigel. Objective: address difficulties in modeling representations involving constraints, uncertainty, and vagueness, especially in intent and capability.
- Introduced the concept of "occurrence" to represent intermediate stages of gradual narrowing from a broad class to a specific instance.
- The draft explores Yang language extensions to better handle these challenges.
- Discussion: Acknowledged the terminology problem and the lack of existing modeling languages that provide this gradual "slide" from vague notions to specific definitions. Feedback was sought on whether the group finds this concept interesting and if similar challenges are encountered.

Decisions and Action Items

IBN Use Cases Merging: The chairs indicated that the decision to merge draft-irtf-nmrg-network-slice-intent, draft-irtf-nmrg-interconnection-intent, and draft-irtf-nmrg-network-measurement-intent into a single document is still open.
- Action Item: Authors of the IBN use case drafts (network-slice-intent, interconnection-intent, network-measurement-intent) are encouraged to collaborate, identify common structures, and present similarities/differences in a future meeting to assess the feasibility and benefits of merging.
AI Challenges Document Contributions:
- Action Item: A volunteer was identified to contribute content on distributed AI (e.g., Federated AI) to draft-irtf-nmrg-challenges-ai-nm.
Green Networking: There was strong support for NMRG to address green networking.
- Action Item: The chairs will consider the feedback for draft-irtf-nmrg-green-networking-challenges regarding its adoption as an NMRG document and how to proceed (as-is or breaking out management specifics).
DTN Interface Requirements:
- Action Item: Authors of draft-irtf-nmrg-dt-interfaces-requirements are encouraged to provide suggestions on applicability of common protocols and add security considerations.

Next Steps

IBN Use Cases: Authors to continue collaboration on identifying commonalities and potential structures for merging or cross-referencing their respective IBN use case documents.
AI for Network Management: Continue seeking feedback on draft-irtf-nmrg-challenges-ai-nm and explore the group's interest in more deeply investigating specific challenges or maintaining it as a "living document" with proposed solutions. Specific contributions on distributed AI are expected.
Distributed AI Services: Authors of draft-irtf-nmrg-distributed-ai-services to refine the draft to incorporate more network-centric aspects and clarify its relation to the AI challenges document.
Performance Oriented Digital Twins: Continue refining draft-irtf-nmrg-performance-digital-twin, especially regarding the distinction between information and action-oriented digital twins and its interface considerations.
DTN Interface Requirements: Authors to incorporate feedback and expand on protocol applicability and security.
Green Networking: The chairs will decide on the next steps for draft-irtf-nmrg-green-networking-challenges, potentially moving towards adoption and further refinement to focus on NMRG's scope.
Modeling Language Boundaries: Authors of draft-farrell-nmrg-model-boundaries to continue seeking feedback from the group and the netmod working group on the challenges identified and the proposed "occurrence" concept.