دانلود رایگان مقاله تعبیه شبکه مجازی با اشتراک گذاری طبقات اولویت متعدد منابع لایه

Abstract

Network virtualization is a promising approach for virtual network operators to configure their own inter-cloud networks flexibly on an inter-cloud substrate network. Virtual network operators specify multiple priority classes in order to satisfy different latency requirements for their inter-cloud network services with a variety of delay-sensitivities on their virtual networks. Furthermore, they may require substrate resource sharing among multiple priority classes in order to reduce the amount of substrate resources assigned to them. Meanwhile, it is desirable for a substrate network provider that multiple virtual networks can share substrate resources since the total amount of substrate resources required can be reduced due to the effect of statistical multiplexing. This paper formulates a novel virtual network embedding problem and proposes a heuristic virtual network embedding method to minimize the total substrate resources required when the virtual network operators request substrate resource sharing among multiple priority classes within their virtual networks. Based on the proposed method, multiple virtual networks can maximally share substrate resources with one another while sharing substrate resources on an equal basis. The effect of substrate resource sharing among multiple priority classes and multiple virtual networks is quantitatively assessed through extensive simulations, and advantageous topologies for requested virtual networks and substrate networks are also presented.

6. Conclusions

This paper formulated a novel virtual network embedding (VNE) problem and proposed a heuristic VNE method to minimize the total amount of substrate resources when each virtual network requires the substrate resources to be shared among its multiple priority classes. The extensive simulations clarified that the proposed VNE method can maximize substrate resource sharing among multiple virtual networks while satisfying the condition for fair substrate resource sharing. This paper quantitatively estimated the effect of substrate resource sharing within each virtual network and among multiple virtual networks. Substrate resource sharing is primarily effective for reducing the required substrate link bandwidth, which means the costly physical link resources can be saved. Substrate resource sharing among multiple virtual networks is significant when the number of priority classes is small. Virtual networks including more virtual links and substrate networks with a larger node degree are good candidates from the perspective of substrate link resource sharing within each virtual network. In contrast, virtual networks with smaller node degrees and substrate networks with a larger node degree are good candidates for substrate link resource sharing among multiple virtual networks. As the number of embedded virtual networks increases, substrate resource sharing among multiple virtual networks becomes more effective for reducing the total required amount of substrate resources.