Abstract

We consider a virtual network (VN) embedding problem on a large-scale substrate physical network. We permit varying capacities and cost rates, and reservation of resources (physical links and nodes) for more profitable later VN requests. Our aim is to maximize the long-run average revenue by controlling the allocation of physical components to arriving VN requests. We propose an index policy that selects, according to state-dependent indices, a set of available physical components for each arrival. The indices are calculated in closed form requiring only intrinsic off-line information about physical components and physical resource requirements. Under reasonable assumptions related to rapidly increasing demands for VNs and resource competition, we show that this proposed policy is asymptotically optimal when the lifespans of embedded virtual components are exponentially distributed. Extensive numerical results demonstrate that the long-run average revenue earned by the proposed index policy rapidly approaches optimality: performance deviations between the index policy and the optimal solution are less than 5% in most of our simulations even for relatively small systems. Our numerical results also indicate that the long-run performance of this policy is relatively insensitive to the form of the lifespan distributions.

抽象的

我们考虑在大型衬底物理网络上的虚拟网络（VN）嵌入问题。我们允许变化的容量和成本率，并预留资源（物理链接和节点）以用于以后更有利可图的VN请求。我们的目标是通过控制对到达的VN请求的物理组件的分配来最大化长期平均收入。我们提出了一种索引策略，该索引策略根据状态相关的索引为每次到达选择一组可用的物理组件。索引以封闭形式计算，仅需要有关物理组件和物理资源需求的内部脱机信息。在与迅速增长的VN需求和资源竞争相关的合理假设下，我们表明，当嵌入式虚拟组件的寿命呈指数分布时，该拟议策略是渐近最优的。大量的数值结果表明，所提出的索引策略所获得的长期平均收入迅速接近最优：即使在相对较小的系统中，我们的大多数模拟中，索引策略与最佳解决方案之间的性能偏差也小于5％。我们的数值结果还表明，该策略的长期性能对寿命分布的形式相对不敏感。在大多数模拟中，即使对于相对较小的系统，索引策略和最佳解决方案之间的性能偏差也小于5％。我们的数值结果还表明，该策略的长期性能对寿命分布的形式相对不敏感。在大多数模拟中，即使对于相对较小的系统，索引策略和最佳解决方案之间的性能偏差也小于5％。我们的数值结果还表明，该策略的长期性能对寿命分布的形式相对不敏感。