Research On Survivability Mechanism In Multi-domain Optical Networks

During the continuing evolution of optical transport network towards high capacity, integrated and intelligent network,the actual optical networks are segmented into several independent domains based upon various policies:management,survivability and difference of technologies,etc.Especially,the intra-carrier and inter-carrier networks are segmented into different domains,thus the optical transport network tends to multi-domain optical networks.Based on the traits which are service-oriented and user-oriented,the expected optical network should support the increasing emerging services,like Date mirroring,Grid Computing,Storage area networks,Video conferencing,OVPN,etc.Let's consider these new emerging services,which have the traits of dynamic,across multi-domain and high-quality QoS.However,under the multi-domain surrounding,each domain is run by independent providers,which makes the multi-domain provisioning a very challenging area as it addresses many open issues in routing,TE,and survivability in multi-domain optical networks.Thereinto,the survivability is the key issue for assessment multi-domain optical networks performance,which has a close relationship with real deployment.It becomes the most stringent problem,which must be resolved as soon as possible.To date, this topic remains largely unexplored in the context of DWDM and standards bodies(such as the ITU,IETF,and OIF) are only now starting to address this issue.In this paper,our research work focus on the survivability mechanism of multi-domain optical networks.Started with the technology background,the paper analyses the problems and challenges posed by multi-domain optical networks resilience.According to the requirement of resilience,we classify associated key issues,and discuss some core techniques;moreover,the direction for future research work is indicated.In addition,the paper introduces the routing protocol and analyses its routing architecture in multi-domain optical networks.After describing the inter-working problem,the paper discusses the E-NNI hierarchical routing model and its implement.This paper put the emphasis on proposing a survivability strategy based on differentiated reliability service for multi-domain optical networks.In the first step,each single domain is abstracted by adopting network topology aggregation techniques.Then,a set of potential intra-domain paths for carrying traffic between domain border nodes for each virtual links is confirmed.At length,an aggregation network is formed via broadcasting routing information in control plane,and then,an end-to-end routing is performed in this aggregation network.For QoS we consider the service bandwidth and reliability.By introducing the condition risk disjoint degree,the need of differentiated reliability service was satisfied.Finally,the measure data simulates validates survivability strategy designed in this paper,the result shows that the proposed survivability strategy can not only meet the reliability requirement of different traffics in multi-domain optical networks,but also reduce the traffic blocking probability and improve the resource efficiency.