The Research Of Hierarchical Routing In ASON

With the increasing development of Internet and the emergence of multi-data service, it’s necessary for OTN to adjust the topology of network dynamically and utilize the network resource effectively. The traditional optical transport network(OTN) can’t meet these requirements. The Automatically Switched Optical Network(ASON) add the control plane to network architecture, in order to realize some intelligent functions, such as links management、call connection management、discovering resource automatically and selecting route path.This paper introduces the concept and architecture of ASON(transport plane、control plane、 management plane),and describe interfaces and signaling protocols in ASON. Then we mainly describe function requirements and modules in control plane, and introduce the Generalized Multi-protocol Label Switching (GMPLS) protocol for the realization of control plane.This paper focus on researches of the hierarchical architecture in ASON. We research the hierarchical routing technology and propose an improved aggregation scheme and routing algorithm for network information, which can improve the QoS of network.