Research On Virtual Network Mapping Algorithm Based On Time Slicing Reservation Scheduling Mechanism

With the continuous evolution of the Internet's network architecture system,the application trend of network virtualization is becoming more and more apparent,and a series of network test platforms based on network virtualization technology have also emerged,such as GENI,FIRE,RISE,etc.China is also building its own large-scale future network test facility in the process.As one of the preliminary research units and planned pilots of this project,our school has launched the construction of a campus-level network virtualization innovation test platform since 2012.It is important to note that the key technology of this platform construction is network mapping.Although there are many research achievements on virtual network mapping,these achievements mainly focus on the research of diversified network topologies,cutting links,and real-time mapping after receiving virtual network.However,in the process of the actual platform construction,the platform encountered practical problem of network experiment application time concentration and system resource system resource congestion.In order to solve this problem and take full advantage of the flexibility of the virtualization platform,this paper proposes a virtual network mapping reservation scheduling mechanism in a network virtualization environment by combining some similar queuing solutions in daily production,which can realize reasonable underlying resource scheduling and improve the system experience of users.Therefore,this paper takes the virtual platform construction of the campus as the research object,and designs a reasonable virtual network mapping algorithm for reservation scheduling as the goal,and completes the following work:(1)This paper first introduces the situation of the campus test platform.Then,the campus test platform iterated from the existing CNYP architecture to a virtualization platform based on Openstack,adopting a flexible networking model of a single computer room.During the operation and maintenance of the campus experimental platform,there is a problem of system resource congestion caused by the concentration of experimental application time.This paper makes relevant research based on this problem.(2)This paper proposes a hybrid scheduling model of traditional real-time mapping and appointment scheduling mapping to improve the utilization and flexibility of the system.Aiming at the problems of insufficient resource use and low system flexibility in the process of network experiment,this paper designs the corresponding appointment scheduling model.this model adopts the non-preemptive priority queuing mode to design the corresponding appointment scheduling mapping model which is based on the classical time window model and combined with the M/M/1 model in queuing theory and the relevant appointment realization methods in other disciplines.(3)Based on the model construction,this paper combines the appointment queuing mechanism and related theories,and uses the method of time discretization and time division to divide the dimensions to design a virtual network mapping algorithm for appointment scheduling.In order to satisfy the reservation algorithm validation,this paper designed a starttime from the current acceptable maximum starting time for each virtual network,and mapped it into the reservation system based on lifetime and starttime.In view of the state problem of virtual network reservation mapping in physical network at every moment,this paper designs the time sharding management mechanism of virtual network reservation system and sets a cutting time interval for the system.In this paper,interval based cutting and recursion are implemented for lifetime and starttime of virtual network to ensure that the virtual network can be successfully mapped in every interval.The simulation results show that the virtual network acceptance rate of reservation mapping is about 10%higher than that of traditional model when the initial virtual network number is small and the virtual network time is short.In the case of a large virtual network lifetime range,the acceptance rate of the reservation mapping mode is only 50%of that of the traditional mode when the virtual network occupies mapping resources for a long time on a large scale.In the case of a small range of life time distribution and uniform,the system using a smaller interval mapping mode can have a higher acceptance rate.In the case of a small range of life time distribution and uniform,the system using a smaller interval mapping mode can have a higher acceptance rate.But in this case,the running time of the system map also increases.By combining the study of acceptance rate and running time,I found that the interval value had better comprehensive performance when it was around half of the virtual network life cycle.In addition,the simulation results under different virtual network bandwidth limitation conditions show that the revenue of reservation mapping method is slightly 1%higher than that of traditional method.This result is consistent with the expectation of this paper that appointment scheduling can better allocate and schedule the underlying physical resources.Based on the above work,according to the simulation results and the short period of use of the campus test platform,we can apply the model algorithm of reservation mapping virtual network to the platform.In this way,the system realizes the efficient utilization of the underlying physical resources and improves the user experience of students in the network experiment.