標題: Cost minimization in placing service chains for virtualized network functions
作者: Wang, Chien Ting
Lin, Ying-Dar
Wang, Chih-Chiang
Lai, Yuan-Cheng
交大名義發表
資訊工程學系
National Chiao Tung University
Department of Computer Science
關鍵字: network function placement;network function virtualization;nonlinear programming;service chains
公開日期: 1-Mar-2020
摘要: Network function virtualization (NFV) places network functions onto the virtual machines (VMs) of physical machines (PMs) located in data centers. In practice, a data flow may pass through multiple network functions, which collectively form a service chain across multiple VMs residing on the same or different PMs. Given a set of service chains, network operators have two options for placing them: (a) minimizing the number of VMs and PMs so as to reduce the server rental cost or (b) placing VMs running network functions belonging to the same service chain on the same or nearby PMs so as to reduce the network delay. In determining the optimal service chain placement, operators face the problem of minimizing the server cost while still satisfying the end-to-end delay constraint. The present study proposes an optimization model to solve this problem using a nonlinear programming (NLP) approach. The proposed model is used to explore various operational problems in the service chain placement field. The results suggest that the optimal cost ratio for PMs with high, hybrid, and low capacity, respectively, is equal to 4:2:1. Meanwhile, the maximum operating utilization rate should be limited to 55% in order to minimize the rental cost. Regarding quality of service (QoS) relaxation, the server cost reduces by 20%, 30%, and 32% as the end-to-end delay constraint is relaxed from 40 to 60, 80, and 100 ms, respectively. For the server location, the cost decreases by 25% when the high-capacity PMs are decentralized rather than centralized. Finally, the cost reduces by 40% as the repetition rate in the service chain increases from 0 to 2. A heuristic algorithm, designated as common sub chain placement first (CPF), is proposed to solve the service chain placement problem for large-scale problems (eg, 256 PMs). It is shown that the proposed algorithm reduces the solution time by up to 86% compared with the NLP optimization model, with an accuracy reduction of just 8%.
URI: http://dx.doi.org/10.1002/dac.4222
http://hdl.handle.net/11536/153976
ISSN: 1074-5351
DOI: 10.1002/dac.4222
期刊: INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS
Volume: 33
Issue: 4
起始頁: 0
結束頁: 0
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