cake-autorate for variable rate links

Background: The CAKE algorithm controls bufferbloat well on constant rate links by using fixed upload and download rate parameters to control the amount of queued data. But many links, such as LTE cell-phones, cable modems, and Starlink have rates that vary from morning to evening, or even from minute to minute. Because CAKE uses fixed parameters, it forces an unpalatable compromise because it can’t adapt to these varying-rate links.

Solution: The cake-autorate algorithm continually measures the current latency and adjusts the parameters of CAKE to minimize latency.

The cake-autorate repo is on Github with an active community on the OpenWrt forum. Here’s an excerpt from the README

cake-autorate is a script that automatically adjusts CAKE bandwidth settings based on traffic load and one-way-delay or round-trip-time measurements. cake-autorate is intended for variable bandwidth connections such as LTE, Starlink, and cable modems and is not generally required for use on connections that have a stable, fixed bandwidth.

CAKE is an algorithm that manages the buffering of data being sent/received by a device such as an OpenWrt router or an Asus Merlin router so that no more data is queued than is necessary, minimizing the latency (“bufferbloat”) and improving the responsiveness of a network. An instance of cake on an interface is set up with a certain bandwidth. Although this bandwidth can be changed, the cake algorithm itself has no reliable means to adjust the bandwidth on the fly. cake-autorate bridges this gap.

cake-autorate presently supports installation on devices running OpenWrt and Asus Merlin.

Status

This is the development (master) branch. New work on cake-autorate appears here. It is not guaranteed to be stable.

The stable version for production/every day use is 3.2.1 available from the v3.2 branch.