The IESG has approved the following document: - 'The FlowQueue-CoDel Packet Scheduler and Active Queue Management Algorithm' (draft-ietf-aqm-fq-codel-06.txt) as Experimental RFC This document is the product of the Active Queue Management and Packet Scheduling Working Group. The IESG contact persons are Spencer Dawkins and Martin Stiemerling. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-aqm-fq-codel/ Technical Summary This memo presents the FQ-CoDel hybrid packet scheduler/AQM algorithm, a powerful tool for fighting bufferbloat and reducing latency. FQ-CoDel mixes packets from multiple flows and reduces the impact of head of line blocking from bursty traffic. It provides isolation for low-rate traffic such as DNS, web, and videoconferencing traffic. It improves utilisation across the networking fabric, especially for bidirectional traffic, by keeping queue lengths short; and it can be implemented in a memory- and CPU-efficient fashion across a wide range of hardware. Working Group Summary An interesting aspect of this document is the combined use of CoDel with FQ for improving flow-isolation properties. The working group had early discussions about the differences between FQ and scheduling mechanisms versus more pure AQM algorithms (like CoDel). This resulted in draft- ietf-aqm-fq-implementation, which describes the terminology and construction of hybrid systems. Any early disagreement in the WG about this seems to have subsided after the subsequent discussions and work to resolve terminology and scope. Document Quality Yes, there are existing implementations and deployments, including in the Linux kernel. There have been other implementation efforts in addition to the editors, and questions have been shared on the AQM mailing list, with clarifications posted in draft updates. The Linux implementation is from the editors of the document, and an independent implementation in FreeBSD was done by Rasool As-Saadi at the Swinburne University. Personnel Wes Eddy (wes@mti-systems.com) is the Document Shepherd. Martin Stiemerling is the responsible AD.
