A configuration is such that among EPC nodes such as an S-GW 104 and a P-GW 105, which form an EPC network, a DNS server 101 selects the EPC node to use based on a selection priority in a DNS resource record registered to the DNS server 101 to thereby distribute loads of the EPC nodes. Further, each of the EPC nodes has a function to transmit, to the DNS server 101, an update request for the DNS resource record in order to lower the selection priority of the DNS resource record relating to the EPC node when the EPC node detects that resource usage of the own EPC node is approaching to an overloaded state. Meanwhile, in response to the update request, the DNS server 101 dynamically updates the DNS resource record, when the DNS server 101 receives the update request from the EPC node.