| An increasing number of applications are making the internet increasingly complex,the network status become more unpredictable.As a result,network congestion will be particularly severe,which presents a poor network performance.To shadow it,network operating costs will rise sharply.However,plenty of redundancy bandwidth resources are wasted.How to improve the network bandwidth utilization becomes very urgent.For this reason,we propose a SDN-based WAN Traffic Optimization.It tracks network status on the traditional IP network infrastructure in real-time,and dynamically modifies part of traffic to the paths whose bandwidth resources are sufficient within the scope of the entire network.So,the network bandwidth utilization will be improved obviously.In this paper,we mainly demonstrate how our proposal deals with variety of network congestion scenarios.Once the network congestion happens,it adjusts some traffic that was routed to the congested paths to other paths which have enough bandwidth to relieve congestion and reduce packet loss.When calculating the adjustment paths of traffic,it selects paths from optional paths which were calculated in the system load stage.As a result,it can achieve the fast response.The adjustment paths of traffic will be established in the form of MPLS/OpenFlow tunnel.So,it won't destroy the stability of the original network.If the congested paths return to normal due to some original traffic through the congested paths disappear or lessen,the established tunnels will be repealed to restore the initial state of the network.Besides,our proposal can solve all the congestion scenarios,such as single congestion,concurrent congestion and sequence congestion.In order to demonstrate the superiority of our proposal,we first verified its feasibility and efficiency on the Abilence and GEANT network through a simulation program.Finally we developed traffic optimized control application server which implemented the proposed SDN-based WAN traffic optimization technology on the laboratory test platform,and the comprehensive test results proved the superiority of its performance. |
