Design And Implementation Of Click-based Virtual Network Function Online Orchestration Platform

With the increasing demand of network innovation,network function virtualization has become a new trend.It seeks to provide network services using virtual network functions instead of traditional network functions.The virtual network functions implemented by these software can be run in commercial virtual machines,which brings advantages in cost,deployment,and maintenance.Virtual network functions are highly concerned by the academic and industrial communities as an important part of network function virtualization.The click modular router is a very popular virtual network function solution based on its modular design concept and has good function expansion.However,currently,the virtual network function based on Click only supports limited customization at runtime,and cannot meet the flexible orchestration of the network function.Therefore,we need to add support for online orchestration functions in Click.However,native Click has the following problems in implementing online orchestration: first,the network function software upgrade time is long;secondly,the network function is upgraded and the network state is lost;thirdly,the higher personalized network function development.In the NFV service function chain application scenario,those problems will be more prominent.Therefore,this paper designs and implements an online orchestration platform CLICK-UP for virtual network functions based on Click and a service function chain application.The main work of this paper includes the following aspects:(1)A network function upgrade module based on service context is designed and implemented.This module changes the original click network function upgrade policy from service context irrelevant to service context related,so that the network function upgrade speed is greatly accelerated,and then the network overhead is reduced by the upgrade;(2)A state synchronization module is designed and implemented.This module unbundles the network state and the Click network function so that the network state will not be lost due to old network function unload and the new network function is loaded with a state synchronization mechanism to synchronize the network state.(3)An online library module is designed and implemented.The module abstracts the userdefined elements authoring specification of Click,which makes it more convenient for users to develop user-defined virtual network functions.At the same time,it provides users with staterelated synchronization interfaces to help users conveniently maintain the state of elements,and provides user-mode and kernel-mode communication interfaces to facilitate users to synchronize network status.(4)CLICK-UP SFC application is designed and implemented based on CLICK-UP platform,an online orchestration platform composed of 1-3 modules.This application can deploy a service function chain for providing network services on the OpenStack platform.The virtual network functions in the chain are driven by the CLICK-UP platform so that the CLICKUP SFC application can enable the service chain to support functions such as network function upgrade and status synchronization.Experimental results show that the CLICK-UP platform can speed up the process of network function generation and can perform state synchronization during the network function upgrade process.The provided online orchestration library can facilitate users to develop userdefined network functions.The CLICK-UP SFC applications also has the corresponding characteristics.