The Research Of Interconnection Between Domains Of Different Vendors In Optical Transport Networks

With the ongoing construction of intelligent optical networking (ION), optical network continues to expand, in order to control and manage the networks more efficiently and more safely, the optical network architecture is divided into different domains. Different operators, as well as the networks within one common operator, can all be divided into different domains. What’s more, the networks using devices from various vendors may also be divided into domains and each domain has its own control and management functions. Multi-domain optical networks are formed in this way. With the development of IP telecommunications, many new services of various granularities quickly rises, such as network video, real-time streaming media communications, high-capacity file transfer and so on. Thus the networks is required to be able to establish service path based on corresponding constraints, quickly, accurately and reliably, especially for inter-domain service path. Path Computation Element (PCE) is used for routing in optical networks and it also has advantages in the inter-domain path computation. The main content of this paper is about the inter-connection of different domains with different vendors.Now it goes smoothly with the progress of international standardization related to interconnection. Both IETF and OIF proposed corresponding key technologies related to interconnection and based on this background, this paper studies the issue from the following aspects:From the view of PCE technology, the paper studies the basic concepts and applications, analyses the architecture of PCE, discusses the computation mode:centralized and distributed mode, explores the PCE discovery and synchronization mechanisms. Then the paper does further studies of PCE communication protocol (PCEP), including protocol structure and process, the main messages types and so on.From the view of interconnection technology, this paper studies main routing and signaling documents related with interconnection. And three methods of inter-domain path computation are introduced, including Per-Domain method, Backward-Recursive PCE-Based Computation Procedure, Hierarchical PCE method. As to signaling the paper analyses external network-network interface (ENNI) and studies the related messages. It also makes a comparison with the PCE technology.Based on the research of interconnection progress, international standards and detailed study of current technology of interconnection, the paper proposed an interconnection method based on PCE after doing further analysis about inter-domain connection scheme. Then it describes the basic idea and concrete steps of the method and does the corresponding simulation test on the existing optical networking platform.In the last part, the paper introduced the two other projects the author has participated. One is realizing the UNI function based on the overlay networking model, the other is constructing the hardware transport platform for the intelligent optical networks.