In a remote access server (RAS), the number of logical link resources, which are circuit resources between the RAS and an ISP server, is set greater than the number of physical link resources, which are circuit resources between the RAS and each terminal device. In the RAS, when a particular circuit undergoes a transition to the dormant state, only the physical link resource is released to allow use by other terminal devices while the logical link resource is maintained unchanged in a connected state, whereby the loss probability is reduced without increasing the number of physical link resources.
