Evaluation of Forwarding Efficiency in NFV-Nodes Toward Predictable Service Chain Performance
Evaluation of Forwarding Efficiency in NFV-Nodes Toward Predictable Service Chain Performance
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DOI：
10.1109/tnsm.2017.2734560
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发表时间：
2017-07
影响因子：
5.3
通讯作者：
Ryota Kawashima;Hiroki Nakayama;Tsunemasa Hayashi;H. Matsuo
中科院分区：
文献类型：
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作者：
Ryota Kawashima;Hiroki Nakayama;Tsunemasa Hayashi;H. Matsuo
在过去的几年里，网络功能虚拟化（NFV）的概念已经体现在商业网络中。基于软件的虚拟网络功能普遍存在转发性能问题，目前已经开发了各种加速技术，如DPDK、vhost-user等。多种替代方案的存在要求网络工程师或运营商选择合适的技术；然而，对于构建高性能nfv节点，目前还没有实用的标准。从他们的观点来看，缺乏共同的基准和对性能特征的理解使得很难预测服务链中逐跳的性能，这导致了在关键任务网络中部署NFV的阻碍。本文重点阐述了三种加速技术在NFV节点中数据包转发的性能特点；包I/O体系结构、虚拟网络I/O和转发引擎。我们研究了三种包I/O体系结构（NAPI、netmap和DPDK）、三种虚拟I/O机制（vhost-net、vhost-user和SR-IOV），以及四个实用的转发程序（Open vSwitch、OVS-DPDK、xDPd-DPDK和Lagopus）和三个参考程序（Linux Bridge、VALE和L2FWD-DPDK）。实验是在40 GbE环境中进行的，我们检查了两台具有不同CPU性能的被测设备。我们讨论了每种技术的性能特征，并对结果进行了定量分析。主要发现是：1)CPU核心速度对吞吐量和延迟/抖动都有影响；2) DPDK可以进行性能预测；3) vhost-user适用于真实环境；4) OVS-DPDK提供了性能和功能的良好组合。
The concept of network functions virtualization (NFV) has been embodied in commercial networks over the past years. Software-based virtual network functions have forwarding performance concerns in general, and various acceleration technologies have been developed so far, such as DPDK and vhost-user. Existence of several alternatives requires network engineers or operators to select appropriate technologies; however, no pragmatic criterion exists for constructing high-performance NFV-nodes. From their points of view, a lack of common benchmark and understanding of performance characteristics makes it difficult to predict hop-by-hop performance in a service chain, which results in prevention of NFV deployment in mission-critical networks. In this paper, we clarify performance characteristics of packet forwarding in NFV nodes focusing on three types of acceleration technologies; packet I/O architecture, virtual network I/O, and forwarding engine in a practical stage. We examined three packet I/O architectures (NAPI, netmap, and DPDK), three virtual I/O mechanisms (vhost-net, vhost-user, and SR-IOV), and four practical forwarding programs (Open vSwitch, OVS-DPDK, xDPd-DPDK, and Lagopus) with three referential programs (Linux Bridge, VALE, and L2FWD-DPDK). The experiment was conducted on a 40 GbE environment and we examined two device-under-test machines having different CPU performance. We argue performance characteristics of each technology and give quantitative analyses of the result. The key findings are: 1) CPU core speed has impact on both throughput and latency/jitter; 2) DPDK can allow performance prediction; 3) vhost-user is appropriate for real environment; and 4) OVS-DPDK provides a good combination of performance and functionality.