The "persistently full buffer" problem has been discussed in the IETF community since the early 80's [RFC896]. The IRTF's End-to-End Working Group called for the deployment of active queue management to solve the problem in 1998 [RFC2309]. Despite the awareness and recommendations, the "full buffer" problem has not gone away, but on the contrary has become worse as buffers have grown in size and proliferated and today's networks proved intractable for available AQM approaches. The overall problem is presently known as "bufferbloat"[TSVBB2011, BB2011] and has become increasingly important, particularly at the consumer edge. This document describes a recently developed AQM, Controlled Delay (CoDel) algorithm, which was designed to work in modern networking environments and can be deployed as a major part of the solution to bufferbloat [CODEL2012]. The goal of the CoDel work is to provide a solution with cost-effective implementation that is particularly well-suited to the consumer edge.