Study On The Survivability Of Layered Multi-Domain ASON And It's Design And Implementation Based On NS

With the rapid development of Optical communication technology, optical network develop toward the large-scale,complex topologies,the intelligent network of business-oriented direction,which demand higher and higher on network survivability.The next generation optical network will be divided into multiple routing domains to improve the performance of routing and signaling,network reliability,scalability and security.It will be essential to define the border of network management and to adopt the technology of distributed management and hierarchical routing. To ensure the network scalability,the detailed information of the connection and bandwidth allocation in one domain will be limited to itself,and only aggregated information will be exposed to the external domains.As a result,no node in the multi-domains has the global information about the whole multi-domain network.In such circumstance, how to provide reliable connections to the traffic and improve the reliability are crucial to the operation of multi-domain network.At first,this article introduces the multi-domain ASON hierarchical network architecture and its routing system,then the survival technology of traditional optical network and the survival of ASON is analyzed, what's more the existing optical multi-domain hierarchical survival techniques is studied,lastly a new Compound layered sub-path share protection algorithm which is based on existing multi-domain optical network protection algorithm is put forward.This paper also does a detailed mathematical analysis for the algorithm theory and describes signaling process of the algorithm particular.At last,through the programming expansion of open source network simulator,a multi-domain hierarchical ASON simulation platform is realized and some improvements about algorithm strategy is achieved through simulation testing(1) ASON multi-domain hierarchical network structure is described cleared,which focused on multi-domain ASON hierarchical network topology and routing calculation process,what's more,some of the key issues of multi-domain layered ASON is discussed in detail,such as the aggregation of routing information,the exchange of routing information and the update of routing information.(2) The survival of the existing network technologies is discussed in detail and the advantages and disadvantages of a variety of network survival mechanisms is analyzed cleared.What is more the characteristics of ASON survival technology and multi-domain hierarchical network survival technology is analyzed cleared.(3) Based on the existing hierarchical ASON multi-domain survival strategy,a new mixed-grade protection of shared sub-path algorithm is put forward.This algorithm computes two paths which are work path and protection path at the upper domain routing for operation.It use "segment by sub-domain,inner domain protection" to provide protection for work path,but to restoration path it use "protection between domains, restoration in inner domains" type to provide protection.Algorithm uses the average shortest path length of the domain and domain average resource utilization for the cost of virtual link weight factor,which estimate he cost of virtual link accurately.Simulation results show that the algorithm has a faster switching speed and better resource utilization efficiency,it provide good recovery performance for inter-domain and inner domain link failures.(4) Multi-domain ASON hierarchical simulation platform which in based NS is realized by programming,multi-domain hierarchical ASON is achieved in the simulation platform,what's more,the signaling mechanism for connection establishment process,the aggregation and update of routing information is include in the simulation platform too.In order to compare,two Recovery approach is put forward,the one is mixed-grade protection of shared sub-path protection algorithm,the other one is path protection.A comparison of performances between two algorithms is performed.