The Research On SDN/NFV Middlebox Dependency-based Routing

Software-defined networking and network function virtualization are hot research directions.Although the combination of software-defined networking and network function virtualization technology can provide operators with a convenient,efficient and flexible management model,the unreasonable deployment of middleboxes will affect the planning of routes,which in turn will bring operators unnecessary routing costs.Based on this,this paper studies the deployment and routing of joint middleboxes that are constrained by multiple targets in unicast and multicast to optimize the total routing cost.First of all,this paper aimed at minimizing routing costs for dependency constraints and link bandwidth constraints of middleboxes.For th first time,the problem of joint optimization of virtual middleboxes deployment and routing was proposed,and the problem was proved to be NP-hard.This cost includes link transmission costs and middlebox deployment costs.Then,a Service Chain Aware Exact Algorithm(SCAEA)for small topology networks is designed.This algorithm can quickly calculate the optimal intermediate based on the given middlebox dependencies and link bandwidth constraints.After comparing with the optimal solution obtained by the mixed integer linear programming mathematical model in the experimental simulation part,the validity of SCAEA is verfied and it has a good application prospect.Considering the complexity of the problem,this paper aims at minimizing the total routing cost for order constraints and delay constraints of the middlebox in multicast,and proposes a Delay-constrained for SC-aware Multicast Routing Algorithm(DSCMRA)with an approximate ratio of O(k).The delay includes the link transmission delay and middlebox processing delay,and the cost includes the link transmission cost and the middlebox deployment cost.The algorithm transforms complex middlebox ordered constraints into graph theory problems that are only subject to delay and cost constraints,and then uses Lagrangian relaxation to relax the delay constraints into cost constraints to eliminate multiple constraints.In the case of dynamic changes of user groups,this article also designs a dynamic multicast algorithm based on this,in order to reduce the total routing cost on the premise of ensuring that new users can join the session group in time within the delay threshold.