Business connection establishment method, path computing unit device and network system

The invention discloses a business connection establishment method capable of improving reliability of business connection, a path computing unit device and a network system. The method comprises the following steps: acquiring information of the source node and destination node of a business, wherein the information of the source node and the destination node comprises information of signal types respectively supported by the source node and the destination node; acquiring information of electricity relay units in other nodes except the source node and the destination node, wherein the information of the electrical relay units at least comprises node identification information of the electrical relay units and information of signal types supported by the electrical relay units; acquiring a head node as the source node and an end node as the destination node and passing through one route of at least one electrical relay unit in the other nodes; and triggering and establishing one end-to-end business connection of the route, wherein the information of the signal types supported by the electrical relay unit passed by the business connection is in accordance with the information of the signal types supported by the source node and the destination node.