%% You should probably cite rfc9331 instead of this I-D. @techreport{ietf-tsvwg-ecn-l4s-id-09, number = {draft-ietf-tsvwg-ecn-l4s-id-09}, type = {Internet-Draft}, institution = {Internet Engineering Task Force}, publisher = {Internet Engineering Task Force}, note = {Work in Progress}, url = {https://datatracker.ietf.org/doc/draft-ietf-tsvwg-ecn-l4s-id/09/}, author = {Koen De Schepper and Bob Briscoe}, title = {{Identifying Modified Explicit Congestion Notification (ECN) Semantics for Ultra-Low Queuing Delay (L4S)}}, pagetotal = 44, year = , month = , day = , abstract = {This specification defines the identifier to be used on IP packets for a new network service called low latency, low loss and scalable throughput (L4S). It is similar to the original (or 'Classic') Explicit Congestion Notification (ECN). 'Classic' ECN marking was required to be equivalent to a drop, both when applied in the network and when responded to by a transport. Unlike 'Classic' ECN marking, for packets carrying the L4S identifier, the network applies marking more immediately and more aggressively than drop, and the transport response to each mark is reduced and smoothed relative to that for drop. The two changes counterbalance each other so that the throughput of an L4S flow will be roughly the same as a non-L4S flow under the same conditions. Nonetheless, the much more frequent control signals and the finer responses to them result in ultra-low queuing delay (sub-millisecond) for L4S traffic without compromising link utilization, and this low delay can be maintained during high traffic load. The L4S identifier defined in this document is the key piece that distinguishes L4S from TCP-Reno-Friendly (or 'Classic') traffic. It gives an incremental migration path so that suitably modified network bottlenecks can distinguish and isolate existing Classic traffic from L4S traffic to prevent it from degrading the ultra-low queuing delay and loss of the new scalable transports, without harming Classic performance. Examples of new active queue management (AQM) marking algorithms and examples of new transports (whether TCP-like or real- time) are specified separately.}, }