F37-ND: No
Rationale
In the selected NFD 24.07 direct-Ethernet composition, EthernetTransport and its unicast/multicast subclasses do not override Transport::getSendQueueLength, whose default is QUEUE_UNSUPPORTED. GenericLinkService::checkCongestionLevel returns immediately for this negative value, so its queue-based congestion marking cannot observe these Ethernet outputs. Multicast v5 suppresses repeated Interests by elapsed-time/backoff rules, not observed segment saturation. The selected forwarding path therefore lacks the localized congestion observation and associated traffic adjustment required by F37.
Assessment method
Pinned inheritance, queue-observation and strategy-source audit
Source context
NFD 24.07 a1480a7c: Transport, Ethernet faces, GenericLinkService and multicast v5
Outstanding qualification
No is restricted to the pinned direct-Ethernet faces and selected multicast v5 strategy. It is not a claim that NDN lacks congestion mechanisms generally: other transports, strategies, consumer algorithms or additional link queue controls may differ. Merely enabling a marking option does not supply unsupported queue telemetry. Packet-injection errors, receive-drop counters and elapsed-time retransmission suppression are not an identified congestion-control feedback loop. No IP AQM layer is selected. Source-level decision, not a congestion experiment; F38 remains separately Pending.
Public sources
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/transport.hpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/generic-link-service.cpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/ethernet-transport.hpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/unicast-ethernet-transport.hpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/multicast-ethernet-transport.hpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/face/ethernet-transport.cpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/fw/multicast-strategy.cpp
- https://github.com/named-data/NFD/blob/a1480a7c947dc6a48ee12c6c0637fc488c0c73a1/daemon/fw/retx-suppression-exponential.cpp
Editorial evidence references
The following identifiers refer to research records not included in this public package; they are not public links.
- round707.html