Router and its method for provide optimal path within a subnetwork in hierarchical transport network

摘要

PURPOSE: A routing apparatus and method for providing the shortest path in a subnetwork of a hierarchy structure communication network are provided to minimize time for selecting the shortest path between a transmitting and receiving points while maintaining various network resource states as it is by defining a state conversion regulation for converting various type of network resource states into one routing state in view of routing. CONSTITUTION: A network form and state managing module(3) collects a state of a network resource from a switch, changes a routing state of a link and a node and stores the routing state in a network form and management information(3b) data base(A-1). The network form and state managing module informs a working flow managing module of the change of the network management state(A-2), ad then the working flow managing module checks the state of a router module and an auxiliary router module(A-3-1,A-3-2). The working flow managing module checks the state of the main/auxiliary router modules, and a router module in an idle state transmits a routing table reconstructing request(A-4-1,A-4-2). The main router module(1) or the auxiliary router module constructs a routing table by using a routing algorithm and store it in a main routing table(1b) or an auxiliary routing table(b)(A-5-1,A-5-2). The main/auxiliary router module sets up its own state as idle, and informs of the working flow managing module that the routing table has completely reconstructed(A-6-1,A-6-2). When the shortest path selection request between transmitting and receiving points reaches the working flow managing module(4), the working flow managing module refers the state of the main/auxiliary routing modules(1,2) and requests a routing service providing and requests a routing service from the idle router module. The main or auxiliary router module searches the shortest path between the transmitting and receiving points designated at the auxiliary routing table(2b), and requests the formed state managing module(3). When the selected link passes the connection acceptance control, the state of a residual bandwidth of the network resource states of the link is changed. If the residual bandwidth is less than 20% of the whole band width, the routing state existing in the network shape and state management information(3b) is changed to be out. The main/auxiliary router module informs a working flow manager on a path passing the connection acceptance control by a connection acceptance control algorithm(3a) of the network shape and state managing module. The working flow manager provides the shortest path to a network management system.