Extensive evaluation on the performance and behaviour of TCP congestion control protocols under varied network scenarios
Extensive evaluation on the performance and behaviour of TCP congestion control protocols under varied network scenarios
复制标题
对不同网络场景下 TCP 拥塞控制协议的性能和行为进行广泛评估
DOI：
10.1016/j.comnet.2019.106872
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发表时间：
2019-11-09
影响因子：
5.6
通讯作者：
Guan, Quanlong
中科院分区：
文献类型：
--
作者：
Lin, Jinting;Cui, Lin;Guan, Quanlong
近几十年来，人们提出了许多TCP拥塞控制（CC）协议来提高TCP在各种网络场景中的性能和可靠性。然而，CC协议通常与诸如延迟和分组丢失的网络条件紧密耦合。考虑到具有不同属性的网络是常见的，例如，有线/无线局域网和长胖网络（LFNs）的研究，研究CC协议在不同网络场景下的性能和行为对于网络管理和开发都至关重要。在本文中，我们进行了全面的测量研究的有效吞吐量，RTT，重传，友好性，公平性，收敛时间和稳定性的最广泛使用的CC协议在有线LAN/WAN和无线LAN（2.4GHz和5GHz的Wi-Fi）。在网络模拟器中，我们还对传输成本、拥塞反向路径和瓶颈队列长度进行了比较研究，并在此基础上揭示了一些有趣的、有独创性的观察结果。我们发现，BBR的有效吞吐量至少是22.5%，低于其他CC协议在无线局域网中，由于不足的起搏速率，即使它总是可以充分利用瓶颈带宽与低RTT的有线网络。我们还观察到BBR的总在线数据量高于CUBIC（例如，当RTT = 100 ms，丢失率= 0.01%时，平均丢失率提高2.37%。此外，BBR可以充分利用瓶颈带宽在大多数队列大小（>= 20包）。令人惊讶的是，我们注意到，作为大多数现代操作系统中的默认CC协议，CUBIC在LAN和无线LAN中都过于激进和不友好，极大地抑制了其他竞争CC协议的有效吞吐量。更具体地说，对于无线LAN中的CUBIC，它比其他CC协议多产生129%的重传。然而，我们也看到，在反向路径严重拥塞的情况下，CUBIC可以充分利用瓶颈带宽。最后，我们还观察到BBR在所有评估的场景中收敛得非常快，而其他CC协议则呈现出不同的结果，例如，Westwood+和Veno在5GHz Wi-Fi网络中的收敛速度比2.4GHz网络更快。(C)2019爱思唯尔B. V.保留所有权利。
In recent decades, many TCP Congestion Control (CC) protocols have been proposed to improve the performance and reliability of TCP in various network scenarios. However, CC protocols are usually closely coupled with network conditions such as latency and packet loss. Considering that networks with different properties are common, e.g., wired/wireless LAN and Long Fat Networks (LFNs), investigating both performance and behaviors of CC protocols under varied network scenarios becomes crucial for both network management and development. In this paper, we conduct a comprehensive measurement study on the goodput, RTT, retransmission, friendliness, fairness, convergence time and stability of most widely-used CC protocols over wired LAN/WAN and wireless LAN (both 2.4GHz and 5GHz Wi-Fi). We also conduct comparative studies with respect to transmission cost, congested reverse path and bottleneck queue size in network simulator.Based on our analysis, we reveal several interesting and original observations. We found that the goodput of BBR is at least 22.5% lower than other CC protocols in wireless LAN due to insufficient pacing rate, even though it can always fully utilize the bottleneck bandwidth with low RTT in wired networks. We also observed that the total on-wire data volume of BBR is higher than CUBIC (e.g., 2.37% higher when RTT = 100ms and loss rate = 0.01%). In addition, BBR can fully utilize the bottleneck bandwidth in most queue sizes ( >= 20packets). Surprisingly, we noticed that as the default CC protocol in most modern operating systems, CUBIC is too aggressive and unfriendly in both LAN and wireless LAN, greatly suppressing the goodput of other competing CC protocols. More specifically for CUBIC in wireless LAN, it generates 129% more retransmissions than other CC protocols. Nevertheless, we have also seen that, in scenario with heavily-congested reverse path, CUBIC can provide full utilization on bottleneck bandwidth. Lastly, we also observed that BBR converges very quickly in all evaluated scenarios, while other CC protocols present varied results, e.g., Westwood+ and Veno converge faster in 5GHz Wi-Fi networks than 2.4GHz networks. (C) 2019 Elsevier B.V. All rights reserved.