基于元能力的SDN功能组合机制

doi:10.11959/j.issn.1000-436x.2015178

摘要/Abstract

摘要：

软件定义网络（SDN,software-defined network）促进了控制逻辑的快速创新，使控制逻辑模块化和模块组合机制成为 SDN 的热点研究方向之一。为了在功能模块统一定义和规范划分的基础上实现网络功能组合，首先，从可重构网络引入“元能力”作为 SDN 控制功能模块划分的原子要素，提出一种基于元能力建模的统一资源描述方法；其次，针对网络功能灵活组合问题，提出了一种基于二级映射的元能力组合模型并给出其启发式算法；最后，为实现元能力组合，设计了作为SDN应用层扩展结构的元能力编排层，并给出基于NetFPGA-10G平台的原型实现。仿真实验与结果表明所提功能组合机制提高了组合效率及节点资源利用率。

关键词: 软件定义网络, 元能力, 功能组合, 资源利用率

Abstract:

Software-defined network (SDN) enables frequent network functional innovation and evolution,making the control function modularity one of the most hot research fields on SDN.Aiming at network-wide functional composition based on unified module definition and function division,firstly,atomic capacity (AC) is introduced as atomic elements of module function division and an AC-based resource description method is proposed; secondly,functional composition module based on two-level mapping is put forward and a heuristic algorithm to calculate the composition is proposed; fi-nally,an AC-orchestrating layer as extended structure of SDN application layer is devised and then a NetFPGA-10G pro-totype implementation is given.Experimental results show that the method can combine functional instances more effec-tively with better resource utilization.

Key words: software-defined network, atomic capacity, functional composition, resource utilization

段通,兰巨龙,程国振,胡宇翔. 基于元能力的SDN功能组合机制[J]. 通信学报, 2015, 36(5): 156-166.

UANTong D,ANJu-long L,HENGGuo-zhen C,UYu-xiang H. Functional composition in software-defined network based on atomic capacity[J]. Journal on Communications, 2015, 36(5): 156-166.

图/表 17

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表1

主要的符号定义及其意义"

符号	含义
P	P= {＜O^P,C^P＞\|O^P?O ,C^P?C}是一个策略
O^P	策略的目标集
C^P	有 n 个元能力的组合链 $C^{P} = {c_{1}^{P}, c_{2}^{P}, \dots c_{i}^{P} \dots c_{n}^{P}}$ ,0＜i≤n,i ,n∈Z⁺
C	网络G中所有元能力的集合
$E_{i}^{P}$	元能力 $c_{i}^{P}$ 的实例集合
$E_{C}^{P}$	策略P映射到的实例链
$J (E_{i}^{P})$	$E_{i}^{P}$ 所有的元素的下标
I(C^P)	C ^P的所有元素的下标
e_ij	$E_{i}^{P}$ 中的一个实例，i∈I(C^P), $j \in J (E_{i}^{P})$
y_ij	表示是否选择实例 e_ij作为元能力 $c_{i}^{P}$ 的实例。1代表选择，0代表不选择
u_ij	e_ij的效用
V_ij	表示实例e_ij的t维性能参数向量 $V_{i j} = {v_{i j}^{1}, v_{i j}^{2}, \dots, v_{i j}^{t}}$
\|J\|	表示J 的元素数量
S_ij	表示实例e_ij的表项所在的节点集
$S_{C}^{P}$	$S_{C}^{P} = {s_{1}^{P}, s_{2}^{P}, \dots, s_{i}^{P}, \dots, s_{m}^{P}}$ 表示策略P最终映射到的执行路径

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参考文献 19

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步骤	下发策略	执行路径	往返延迟
0	installAC({E1},{Firewall})	—	∞（Blocked）
	installAC({E3},{NAT})
1	installPolicy＜{Host1,Host2},{Firewall}＞	E1→E2→E4	0.19 ms
2	installPolicy＜{Host1,Host2},{Firewall,NAT}＞	E1→E2→E3→E4	0.45 ms
3	installPolicy＜{Host1,Host2},{NAT,Firewall}＞	—	∞（No Path）

场景	下发元能力	下发策略	执行路径
	installAC({E1},{Firewall})		—
元能力组合	installAC({E3},{NAT})	installPolicy＜{Host1,Host2},{Firewall,NAT }＞	E1→E2→E3→E4
	installAC({E4},{NAT})		E1→E2→E4
无功能组合	—	installPolicy＜{Host1,Host2},{Firewall,NAT}＞	E1→E2→E4