The IESG has approved the following document: - 'PIE: A Lightweight Control Scheme To Address the Bufferbloat Problem' (draft-ietf-aqm-pie-10.txt) as Experimental RFC This document is the product of the Active Queue Management and Packet Scheduling Working Group. The IESG contact persons are Mirja Kühlewind and Spencer Dawkins. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-aqm-pie/ Technical Summary Bufferbloat is a phenomenon where excess buffers in the network cause high latency and jitter. As more and more interactive applications (e.g. voice over IP, real time video streaming and financial transactions) run in the Internet, high latency and jitter degrade application performance. There is a pressing need to design intelligent queue management schemes that can control latency and jitter; and hence provide desirable quality of service to users. This document presents a lightweight active queue management design, called PIE (Proportional Integral controller Enhanced), that can effectively control the average queueing latency to a target value. Simulation results, theoretical analysis and Linux testbed results have shown that PIE can ensure low latency and achieve high link utilization under various congestion situations. The design does not require per-packet timestamp, so it incurs very small overhead and is simple enough to implement in both hardware and software. Working Group Summary There were no matters of large controversy, though there have been some criticisms of PIE. The IPR did not seem to be a blocking point for anyone, but some participants prefered algorithms free of IPR. There are multiple algorithms that were proposed to the AQM working group, and there are still some developing. Some aspects of the PIE design were critiqued, and there are some identified matters for future research, but there did not seem to be any disagreement that this is useful to publish at this time. It is understood that this does not block other algorithms or improvements from happening. The critical reviews are useful in understanding the differences with other algorithms, and making improvements to PIE while in experimental stage. Document Quality Yes, there are multiple existing implementations, including in simulations, Linux, FreeBSD, and some may be based on description in the DOCSIS specification. All of the implementation experience was helpful in improving the document quality and clarity when describing the algorithm. A very thorough technical review was done by Bob Briscoe, and posted as a complete document itself. Personnel Wesley Eddy (wes@mti-systems.com) is the document shepherd, and Mirja Kühlewind (ietf@kuehlewind.net) is the AD.
