Research On SDN-based Distributed Virtual Network Embedding Method

With the continuous development of network technology,various new network forms,such as the Internet of Things and Data Centers.They have placed higher demands on network services.Under the premise of flexible and sharing the underlying network resources,shielding the underlying network software and hardware differences and making full and reasonable use of network resources have become a direction to solve the network development bottleneck.Virtual network mapping has become an important solution.At present,the problem of virtual network mapping has been fully studied.However,in the centralized method,both the virtual node mapping and the virtual link mapping are performed in the same control node,the mapping time is long,and the overall mapping efficiency is reduced;in other improved strategies,although multiple virtual control nodes can be allocated,the stability is poor,and additional control area division is required,which increases the overall mapping workload.In view of the above-mentioned centralized virtual network mapping,using the idea of centralized control of Software Defined Network(SDN)framework,integrating SDN Controller for centralized mapping and multiple physical node distributed mapping methods,a method is proposed.The new virtual network mapping method not only reduces the mapping time,but also realizes centralized management and control of physical resources,thereby improving the mapping efficiency of the virtual network as a whole.The main tasks are as follows:(1)A new virtual network mapping architecture is proposed.In this architecture,the SDN Controller centrally controls the physical network resources,communicates with each physical node through the OpenFlow protocol,and uses the greedy algorithm to implement mapping of virtual nodes;each physical node exchanges information through TCP/IP protocol,and masters The location information of other physical nodes in the N hop;in each virtual network mapping process,the virtual link mapping process is tended to be distributed by using the K shortest path algorithm.(2)According to the architecture design,a virtual node mapping algorithm and a virtual link mapping algorithm that adapt to the architecture are formed.The algorithm design is based on C language and MATLAB language.Firstly,the pseudo-code is used to derive the running process,and then the established scheme is completed by means of Salam network generation algorithm,greedy algorithm and K shortest path algorithm.(3)In the Windows 7 operating system,two algorithms are implemented using MATLAB software.By modifying the different parameter values and setting the output mode separately,the results of the operation are represented by means ofcharts.Through simulation experiments,the designed algorithm has an increase of25.7% in mapping time compared to the traditional two-step algorithm.During the experiment,different N values are selected,and the hop count distance of the physical node collecting information is different,and the virtual network mapping effect and the benefit/cost ratio are different.In the actual underlying network,in order to achieve greater market,higher and lasting service benefits,operators will use different physical devices,operational strategies,communication protocols,etc.for commercial competition.Virtual network mapping can shield the differences in the underlying network,serve different users in the same shared network,and study its mapping strategy will have great market value and practical significance.