Abstract: Disclosed is an exchange system, to which a plurality of extension terminals are connected, for effecting a connection to any of the extension terminals upon receiving, from a network, incoming-call information which includes at least extension terminal designating information or attribute information. Also disclosed is a call connecting method in this exchange system. The plurality of extension terminal designating information and the extension terminal information are stored, in correlation, in a first memory, and representative extension information corresponding to the attribute information are stored in a second memory. Reference is made to the first memory to decide an extension terminal corresponding to the extension terminal designating information contained in the incoming-call information. When a decided extension is incapable of receiving an incoming call, a connection is made to a substitutable extension.