Controlled Delay Approximate Fairness AQM

Document Type Expired Internet-Draft (individual)
Authors Jonathan Morton  , Peter Heist 
Last updated 2020-09-10 (latest revision 2020-03-09)
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This note presents CodelAF, or Controlled Delay Approximate Fairness in full, as an alternative to single-queue AQM or Fair Queue implementations in the low-cost or high-speed network hardware spaces. It builds on the seminal work in Codel [RFC8289], and guides multiple competing flows towards similar throughputs by differential congestion signalling, whilst requiring only a single FIFO queue. It may also be combined with CNQ [I-D.morton-tsvwg-cheap-nasty-queueing] to provide a latency optimisation for sparse flows.


Jonathan Morton (
Peter Heist (

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