1. A transmission system having: a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and a client side router which communicates with a client device for receiving the content, the system comprising: a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths defined between the plurality of delivery server side routers and the client side router; and a path control unit for determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths, based on sums of the server load states and the respective individual link load states stored in the database.