Multi-Provider Service Chain Embedding With Nestor
Multi-Provider Service Chain Embedding With Nestor
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DOI：
10.1109/tnsm.2017.2654681
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发表时间：
2017-03
影响因子：
5.3
通讯作者：
David Dietrich;Ahmed Abujoda;Amr Rizk;Panagiotis Papadimitriou
中科院分区：
文献类型：
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作者：
David Dietrich;Ahmed Abujoda;Amr Rizk;Panagiotis Papadimitriou
NF （Network function）虚拟化将NFs与底层中间件硬件解耦，并促进它们在虚拟化网络基础设施上的部署。这基本上为NFs迁移到云（即NF-as-a-Service）铺平了道路，从而大大减少了企业的中间箱投资和运营成本。在这种情况下，服务链（表示企业网络中的中间盒策略）应该映射到数据中心网络，以确保正确性、资源效率以及与提供商策略的遵从性。网络服务嵌入（NSE）问题被两个具有挑战性的方面进一步加剧：1)某些NFs（例如，缓存和WAN优化器）引起的流量扩展和2)NF位置依赖。流量扩展需要不同于服务链中指定的资源预留，而NF的位置依赖性，再加上NF提供商（NFPs）有限的地理足迹，增加了跨多个NFPs的NSE需求。在本文中，我们提出了一个整体的解决方案，多提供者的NSE问题。我们将NSE分解为：1)由集中式协调器执行的nf -图分区和2)到数据中心网络的nf -子图映射。我们提出线性规划公式来推导这两个问题的近最优解。我们通过引入支持需求转换的新服务模型来解决流量扩展的挑战。我们还定义了nf图划分的拓扑抽象。此外，我们还讨论了使用我们的NSE编排器（Nestor）跨多个nfp嵌入服务链所需的步骤。我们对多提供商NSE进行了评估研究，重点是针对客户端和nfp量身定制的nf图分区优化。我们的评估结果进一步发现，由于需求转换，在服务成本和资源消耗方面节省了大量资金。
Network function (NF) virtualization decouples NFs from the underlying middlebox hardware and promotes their deployment on virtualized network infrastructures. This essentially paves the way for the migration of NFs into clouds (i.e., NF-as-a-Service), achieving a drastic reduction of middlebox investment and operational costs for enterprises. In this context, service chains (expressing middlebox policies in the enterprise network) should be mapped onto datacenter networks, ensuring correctness, resource efficiency, as well as compliance with the provider’s policy. The network service embedding (NSE) problem is further exacerbated by two challenging aspects: 1) traffic scaling caused by certain NFs (e.g., caches and WAN optimizers) and 2) NF location dependencies. Traffic scaling requires resource reservations different from the ones specified in the service chain, whereas NF location dependencies, in conjunction with the limited geographic footprint of NF providers (NFPs), raise the need for NSE across multiple NFPs. In this paper, we present a holistic solution to the multi-provider NSE problem. We decompose NSE into: 1) NF-graph partitioning performed by a centralized coordinator and 2) NF-subgraph mapping onto datacenter networks. We present linear programming formulations to derive near-optimal solutions for both problems. We address the challenging aspect of traffic scaling by introducing a new service model that supports demand transformations. We also define topology abstractions for NF-graph partitioning. Furthermore, we discuss the steps required to embed service chains across multiple NFPs, using our NSE orchestrator (Nestor). We perform an evaluation study of multi-provider NSE with emphasis on NF-graph partitioning optimizations tailored to the client and NFPs. Our evaluation results further uncover significant savings in terms of service cost and resource consumption due to the demand transformations.