DREAM-Oriented Signaling Scheme And Cross-Domain Service Recovery Strategy In Optical Network

As optical network expands rapidly, multi-layer and multi-domain structure become the development trend of large scale optical network. Multi-layer and multi-domain structure can promote the efficiency and flexibility of network supervisory control, but it’s special structure cause trouble for the process of routing based on the strategy and constraint conditions. IETF work group has summarized the requirement of multi-layer and multi-domain GMPLS network, and proposed a conception of Path Computation Element (PCE). A cross-domain path computation request is cooperative processed by a series of PCEs. In the structure of multi-layer and multi-domain, original signaling scheme can not supply the demand any more. Moreover, considering the PCEs, signaling scheme has to be more complex.To solve the above problems, based on the DREAM structure (Dual Routing Engine Architecture in Multi-layer/Multi-domain/Multi-constraint optical networks), I participate in constructing the multi-layer an multi-domain contorrl plane of optical network experiment platform and design signaling module including reroute scheme. Finally a novel dual-weight recovery (DWR) scheme is proposed for failure in multi-domain optical networks. There are three parts in this paper:(1) In DRE-based optical network, design and realize sigaling scheme for control plane. To cooperate with DRE-based routing policy, this paper extends resource reservation protocol with adding lay/domain information object, tunnel list object and soon on. The sigaling module has feature of high cohesion and low coupling. It can apply to build or tear services in DREAM-oriented optical network.(2) When failure occures in multi-layer and multi-domain network, this signaling scheme can handle services properly, and treat them according to their failure layer including service layer, tunnel layer and wavelength layer. It can dynamicly switch between quick reroute and end-to-end reroute and it can also automatically search tunnel which has idle resource to carry the services affected by failure.(3) A restoration scheme has been designed for multi-domain optical network, which solve the problem of resource conflict during fast rerouting. This scheme propose the concept of dual-weight (normal weight and protect weight) recovery for the first time. Routing requests of normal service rely on sum of the two weights, while for rerouting requests, PCEs just consider the normal weight without proctect weight. When failure occurs, proctect weight will be increased to a high level which cause the rereouting request can get the prior path.