Research On Key Technologies Of SDN-based Optical Access Network Control Architecture

In recent years,as the last mile of the information highway,the flexibility of the optical access network architecture,the stability of traffic,and the security of user services are facing increasing challenges.The Software Defined Network(SDN)supported by the Open Flow protocol has been widely used and developed in the field of access networks as an ideal solution that can provide good abstraction,which has important practical significance and practical value,but it still faces the following problems: First,the control architecture of the SDN-based optical access network can't meet the needs of reality to integrate multiple resources,so as to shield the differences of underlying physical equipment and achieve the openness the of access platform;Second,the proposed bandwidth allocation algorithms and strategies can not match the corresponding architecture,so that the advantages of intelligent control and scheduling of SDN cannot be truly realized;Third,at present,all parties are blindly pursuing efficiency in the area of optical access networks,and lack of attention to security mechanisms,so there is no systematic and effective security scheme.Based on the existing software-defined optical access network research,this paper focuses on the above issues and has carried out research on several key technologies of SDN-based optical access network control architecture,and aims at optimizing network architecture,improving network performance,and enhancing network protection.The main research contents are as follows:Firstly,in order to effectively improve the utilization of network resources of optical access network,and solve the problem of lacking dynamic control and intelligent scheduling of data traffic for different users,we combine the advantages of optical and wireless convergence technology and software-defined networking to design a control architecture for access network based on SDN.We also designed the functional modules of the related devices,and the overall interaction process of the architecture.This architecture adopts the idea of layered control and deploys Open Flow agents to dynamically assign certain authorities of the controller to the OLT.Moreover it extends the control depth of the controller to the ONU to enhance the overall robustness of the architecture.Secondly,for the problems of difficult to balance the multi-service Qo S and the low utilization of bandwidth resources of the SDN-based optical access network,we designed a layered dynamic bandwidth allocation scheme based on the proposed cross-layer control architecture of the access network.The scheme maps the front-end and back-end network services based on real-time collection of global network information,and divides them into three service queues: EF(Expedited Forwarding),AF(Assured Forwarding),and BE(Best-effort).According to different service requirements and queue priority,the network resources are scheduled accurately and adaptively to fully improve the performance of the whole network.Thirdly,for the problem of secure communication between devices caused by the sharp increase in the number of OLTs and ONUs connected to the control center in the software defined optical access network(SDOAN)environment,we propose a lightweight identity two-way authentication scheme(LTWA)based on the cryptographically generated address(CGA)algorithm combined with the hash generated address(HGA)algorithm.Based on the information interaction method of the Open Flow protocol,the scheme introduces the CGA algorithm and the HGA algorithm without third party participation,so as to complete the first and the non-first authentication binding between the communication nodes respectively,which effectively prevents an attacker from forging or tampering with authentication interaction messages,thereby establishing an end-to-end trusted connection in the access network.