During the COVID-19 pandemic the Comcast network performed well in response to unprecedented changes in Internet usage and video communications applications that are sensitive to network latency have exploded in popularity. However, in today's typical networks-such as a home network-those applications often degrade if they are sharing a network link with other network traffic. This is a problem caused by a network design flaw often described using the term 'buffer bloat'. Several years ago, Comcast helped to fund research and development in the technical community into new Active Queue Management (AQM) techniques to eliminate this issue and AQM was later built into Data Over Cable Service Interface Specification (DOCSIS) standards. Just prior to the pandemic, Comcast also deployed a large-scale network performance measurement system that included a latency under load test. In addition, Comcast happened to deploy two otherwise identical cable modems; one with upstream AQM enabled, and the other without. This fortuitous confluence of events has enabled Comcast to perform a comparative analysis of the differences between cable modem gateways using AQM with those that lack that enhancement, at a unique level of scale across many months of time and millions of devices. The data reveals significantly better upstream latency under load performance when AQM is used. For the device with AQM, most of the latency under load tests resulted in 15-30 milliseconds of latency. In comparison, the device without AQM averaged roughly 250 milliseconds of latency, between 8-16 times higher, a highly significant difference to the end user quality of experience. These large-scale measurement comparisons should provide additional data to justify accelerated deployment of AQM in DOCSIS and other Internet Service Provider networks and user-purchased home network equipment.

中文翻译：

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在 COVID-19 期间通过主动队列管理 (AQM) 改善延迟

在 COVID-19 大流行期间，康卡斯特网络表现良好，以应对互联网使用的前所未有的变化，对网络延迟敏感的视频通信应用程序已大受欢迎。然而，在当今的典型网络（例如家庭网络）中，如果这些应用程序与其他网络流量共享网络链接，它们通常会降级。这是由网络设计缺陷引起的问题，通常使用术语“缓冲区膨胀”来描述。几年前，康卡斯特帮助技术社区为新的主动队列管理 (AQM) 技术的研究和开发提供资金，以消除这个问题，后来 AQM 被内置到有线数据服务接口规范 (DOCSIS) 标准中。就在疫情爆发前，Comcast 还部署了一个大规模网络性能测量系统，其中包括负载测试时的延迟。此外，康卡斯特碰巧部署了两个完全相同的电缆调制解调器；一个启用了上游 AQM，另一个没有。这种偶然的事件汇合使康卡斯特能够对使用 AQM 的电缆调制解调器网关与那些缺乏该增强功能的电缆调制解调器网关之间的差异进行比较分析，以跨越数月时间和数百万设备的独特规模水平。数据显示，当使用 AQM 时，负载性能下的上游延迟明显更好。对于具有 AQM 的设备，负载测试下的大部分延迟导致 15-30 毫秒的延迟。相比之下，没有 AQM 的设备平均延迟大约为 250 毫秒，高出 8-16 倍，最终用户体验质量的显着差异。这些大规模测量比较应提供额外数据，以证明在 DOCSIS 和其他互联网服务提供商网络和用户购买的家庭网络设备中加速部署 AQM 是合理的。