Abstract Video streaming today shows a widespread success, representing already the greatest portion of the Internet's IP traffic. The most common approach in today's networks is to adopt HTTP-based solutions, such as the Dynamic Adaptive Streaming over HTTP (DASH) protocol. This choice allows using general purpose web clients (web browsers) to access video streaming, while implementing a client-side dynamic rate adaptation of the streaming service. In fact, such HTTP-based approach must cope with intrinsic dynamism of the client's access network, which is a function of concurrent traffic from either the same user or other users sharing the same network resources. In addition, the network virtualization era fosters dynamic management of virtual resources that can lead to even further network variability, with significant changes of the end-to-end link characteristics in terms of bottleneck bandwidth and physical delay. Last but not least, the fruitful utilization of the satellite component in the future 5G networks implies to experience physical delay changes over a larger value range. Therefore, DASH flows will run on communication scenarios with higher and higher variability: this means that the client-side dynamic adaptation feature of DASH becomes a critical component of the whole service. This paper aims to investigate performance of two main DASH Adaptive Bit Rate (ABR) algorithm categories, throughput-based and buffer-based, over a simulated time-varying end-to-end link modeling the joint effects of continuous traffic and link changes. The goal is to provide statistical overview on the DASH ABR adaptation on challenging scenarios in order to draw some baseline recommendations for possible enhancements or modifications. The overall performance analysis is based on a customized script running in the Network Simulator 3 (NS-3).

中文翻译：

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随时间变化的端到端链路的 DASH 性能分析

摘要 今天的视频流显示了广泛的成功，代表了互联网 IP 流量的最大部分。当今网络中最常见的方法是采用基于 HTTP 的解决方案，例如基于 HTTP 的动态自适应流媒体 (DASH) 协议。此选择允许使用通用 Web 客户端（Web 浏览器）访问视频流，同时实现流服务的客户端动态速率适配。事实上，这种基于 HTTP 的方法必须处理客户端访问网络的内在动态，这是来自同一用户或共享相同网络资源的其他用户的并发流量的函数。此外，网络虚拟化时代促进了虚拟资源的动态管理，这可能导致进一步的网络可变性，随着端到端链路特性在瓶颈带宽和物理延迟方面的显着变化。最后但并非最不重要的是，卫星组件在未来 5G 网络中的卓有成效的利用意味着在更大的值范围内经历物理延迟变化。因此，DASH 流将运行在可变性越来越高的通信场景上：这意味着 DASH 的客户端动态适配特性成为整个服务的关键组成部分。本文旨在研究基于吞吐量和基于缓冲区的两种主要 DASH 自适应比特率 (ABR) 算法类别在模拟时变端到端链路上的性能，该链路对连续流量和链路变化的联合影响进行建模。目标是在具有挑战性的场景中提供有关 DASH ABR 适应的统计概述，以便为可能的增强或修改得出一些基线建议。整体性能分析基于在 Network Simulator 3 (NS-3) 中运行的自定义脚本。