In order for more effectively supporting a Dedicated Core Network, there is provided a network system including a first node (30) that establishes secure connection with a UE (10) initially attempting to attach to a network, through a radio base station (20), and a second node (40) to which the UE (10) is redirected from the first node (30) through the radio base station (20). Upon the redirection, the first node (30) sends information on the first node (30) itself to the second node (40) through the radio base station (20). The second node (40) uses the information to retrieve security context necessary for establishing the connection with the UE (10) from the first node (30).