Scheme Design Of Metropolitan Area Network CGN Centralized Backup

It’s a long-term and complex process that IPv4-to-IPv6 transition is completed.In order to solve the problem that public IPv4 address is insufficient in this period, the technique of Carrier grade NAT (CGN) is paid attention to by the carries. And now it is deployed in large-scale.To improve the efficiency of transition technique deployment and save network investment, a solution to centralized CGN backup deployment that gives due consideration to network security is put forward in this paper. The major research results in this paper are as follows:The basic principle and deployment of CGN are studied. Based on CGN device models and deployment locations, the CGN devices are classified, advantages and drawbacks of deployment with each type of CGN device deployed are analyzed, and some problems in deploying CGN on live networks are summarized. Application scenes and the influences of CGN technique are provided in this paper.Research on CGN centralized backup technology. It is Described how to use centralized CGN backup techniques to optimize 1:1 redundancy for distributed CGN boards that are installed on BRASs. The optimized solution features distributed CGN boards installed on BRASs+centralized N:l backup. Without network security compromised, the optimized solution will reduce investment by 40%, compared with the original deployment mode. This document describes how to perform backup switching if a fault occurs. PBR can be configured on interfaces of service access boards on BRASs/SMEs or on MAN egress CRs’ interfaces. With PBR configured, if a fault occurs, a distributed CGN board switchover can be performed immediately. For the user source tracing issue when a fault occurs, this document describes how to trace user sources in this solution.Research on the related issues of CGN centralized backup and backup deployment. Deployment roadmap is provided. Improvements to be made on BRASs/MSEs, CRs, centralized CGN, support systems related to centralized CGN backup deployment on live networks, as well as requirements for deploying PBR and user source tracing are described. Key deployment issues, such as address planning, device version upgrade, log server and AAA platform deployment modes, and CGN capability and capacity are analyzed in this paper.The distribution of centralized CGN and distributed CGN is studied. Based on various fault rates of distributed CGN boards, the possibility of using a single centralized CGN device to provide successful backup for distributed CGN boards, as well as the number of distributed CGN boards is raised. Based on the backup capability of a centralized CGN device, this paper also provides the maximum number of distributed CGN boards for which a single fully configured centralized CGN device can back up.Field test of CGN centralized backup plan. Test scheme and network equipment configuration are given. And the ability of the backup, the user’s traceability, the application effect and so on are tested, the test results meet the expected results, and the feasibility of the scheme is proved.