Session Date/Time: 12 Nov 2021 12:00

dtn

Summary

The dtn working group meeting at IETF 112 covered critical updates on existing documents, significant progress on the re-chartering process, and presentations on new technical work. Key highlights include the imminent publication of four core DTN RFCs, the successful negotiation of the working group's new charter, and discussions on a Wireshark dissector, a COSE-based security context for BPSec, and scalability for large-scale DTNs. The session also featured an in-depth gap analysis of existing IETF network management protocols against the unique requirements of challenged DTN environments, and a presentation on an asynchronous network management system implementation.

Key Discussion Points

Administrative Overview: The chairs (Rick Taylor, Ed Birrane) welcomed participants, reviewed standard IETF notewell, participant guide, and procedures. Note-taking via Etherpad (CodyMD) was encouraged.
Document Status (Big Four):
- BPv7, BPSec, Default Security Context for BPSec, and TCPCLv4 are all at the RFC Editor stage.
- Expected to complete editorial work within two weeks, entering AUTH48 state.
- Anticipated to become RFCs before the end of the year, marking a successful completion of the current charter cycle.
Working Group Charter Update:
- The proposed re-charter encountered blocking comments from the Operations (network management) and Routing areas.
- Resolution: Chairs and ADs (Zaheed Akhtar) negotiated updated charter text, explaining the unique focus on challenged networks. Blocks have been removed, and the charter is expected to go to IESG telechat on December 12th for approval.
- Coordination with Other Areas: The updated charter explicitly states the dtnWG will coordinate closely with Security, Routing, and Operations/Management areas, seeking early peer review for its work.
- Operations and Management Focus:
  - The existing "Asynchronous Management Architecture" (AMA) document will be clarified and likely renamed (e.g., "Delay Tolerant Network Management Architecture").
  - It will analyze existing asynchronous management work (Netmod, Yang Push, RESTCONF, COAP/CoreConf) from other IETF areas and perform a gap analysis to highlight unique DTN needs (e.g., long latencies, no end-to-end path, autonomous/rules-based execution).
  - Future work includes application data models, management protocols, and CBOR encodings.
- Routing Focus:
  - Routing remains explicitly out of scope for the next charter cycle.
  - Future work on DTN routing, if undertaken, will be done hand-in-hand with the Routing Area (e.g., potentially a new WG or group within the Routing Area).
  - The dtnWG will liaise with the MANET (Mobile Ad Hoc Networking) working group, especially regarding management issues, due to potential crossovers.
Milestones for New Work: Chairs will contact authors of personal drafts aligned with the new charter to solicit estimated dates for working group adoption to populate the data tracker milestones.
Administrative Record Types for BPv7 (Brian Sipos):
- Presented a draft to update the IANA registry for BPv7 administrative record types, adding a "Bundle Protocol Version" column for consistency with other BPv7 registries.
- Includes explicit reservation of code point 0 and an experimental range (large values).
- Driven by a need for a new administrative record type in the ACME WG for node ID validation.
Wireshark Dissector Update (Brian Sipos):
- Announced that BPv7, BPSec, and TCPCLv4 dissectors have been merged into the main Wireshark upstream project.
- This includes generic bundle dissection, version introspection, dissector tables for extensibility, defragmentation logic, and sequence analysis.
- Opportunistic message dissection for TCPCLv4/v7 could be added in the future, potentially as an informational document.
COSE Security Context for BPSec (Brian Sipos):
- Proposed a new security context for BPSec that leverages COSE (CBOR Object Signing and Encryption).
- Aims to provide robust support for symmetric keys and PKI algorithms, addressing limitations of the default BPSec security context (e.g., key rotation, internet-facing scalability).
- Benefits from COSE's existing syntax, extension points for future algorithms (e.g., post-quantum), and existing library/tool support.
- Proposes a minimal set of interoperability requirements for COSE within BPSec, aligning with existing TLS certificate profiles.
Scalability Issues in Big DTNs (Scott Burleigh):
- Presented a proof-of-concept for scaling DTN networks to thousands or millions of nodes, focusing on automated forwarding and node deployment.
- Inter-regional Forwarding: Introduced the concept of "regions" (sets of nodes under a single, consistent routing regime, similar to autonomous systems) and "passageway" nodes (connecting regions, analogous to gateways). Uses probe bundles and feedback for efficient inter-regional forwarding.
- DTN Node Auto-configuration (DNAC): Demonstrated a system built on ION capabilities (automatic contact plan synchronization, bundled multicast, DTKA) for rapid deployment. Showed a simulated deployment of 29,000 nodes in 24 minutes.
- Discussion: Parallels drawn to IETF routing concepts like Interior Gateway Protocols (IGPs) and Exterior Gateway Protocols (EGPs), AODV for opportunistic routing feedback, and PIM for multicast tree building. The term "passageway" versus "gateway" was discussed.
Asynchronous Management Architecture Next Steps (Emery) / Asynchronous Network Management System (Sarah Hubbell):
- Emery's Presentation: Performed a gap analysis of existing IETF management protocols (SNMP, Yang/Netconf/Restconf, Yang Push, CoAP/CoreConf, Autonomic Networking/ANIMA) against DTN's unique "challenged network" definition (RFC 7228) and management needs (e.g., autonomous parameterized procedure calls, intelligent push, rules-based execution). Concluded that existing protocols don't fully meet DTN-specific requirements.
- Sarah Hubbell's Presentation: Introduced the Asynchronous Network Management System (ANMS) project at JHU/APL. This tool aims to integrate DTN standards (including AMP and future changes) to manage challenged networks. Goals include monitoring/controlling nodes, interoperating with existing tools, and managing BP agents. It is being built modularly for distributed deployment and will be released open source in spirals, with the first release expected in early 2022.

Decisions and Action Items

Charter: The updated charter text will be submitted for IESG telechat approval on December 12th.
Administrative Record Types for BPv7: Chairs to issue a call for working group adoption on the mailing list.
COSE Security Context for BPSec: Chairs to issue a call for working group adoption on the mailing list.
Milestones: Chairs to send an email to authors of personal drafts asking for estimated dates for working group adoption.
AMA/Management Gap Analysis: Emery (or a collaborator) to prepare and present the inverse of the gap analysis (highlighting DTN unique needs and why existing solutions are insufficient) to the Netmod community/Ops Area at a future IETF meeting.
Personal Drafts: Authors with personal drafts on topics in the new charter are encouraged to re-issue them to keep them active in the document tracker.

Next Steps

Monitor the IESG charter approval process.
Conduct mailing list discussions and working group adoption calls for the Administrative Record Types and COSE Security Context drafts.
Authors to provide milestone dates for personal drafts.
Continue work on the Delay Tolerant Network Management Architecture document, incorporating gap analysis and clarifying unique DTN needs, coordinating with Ops Area.
The ANMS project will proceed with its first open-source release in early 2022, seeking community feedback.
Mailing list discussions are anticipated on the scalability concepts (regions, auto-configuration) and their parallels with existing IETF routing and management mechanisms.
Ed Birrane to present to the MANET working group session three (IETF 112).
The dtnWG plans to meet at the next IETF (virtually or in-person).