By assigning a fixed home address to an MN, Mobile IPv6 assures the arrival of each content at the MN 1. In order to allow the user to receive a Mobile IPv6 service, it is necessary to provide the MN 1 with a Mobile IPv6 function for making applications conform to IPv6. However, there are only few such MNs 1. In addition, the MN 1 does not have a function for implementing an IPsec process repeatedly on a packet transmitted to and received from another apparatus. A scenario processing port 23 employed in the MN 1 includes a means, which is used for selecting a process according to a communication method and carrying out the selected process when a response to a Mobile IPv6 location registration message is received. By providing the scenario processing port 23 with a means for selecting a communication method, a function can be added to the MN 1 with ease. In addition, by providing the MN 1 with a means for implementing an IPsec process a plurality of times, it is possible to provide a communication apparatus according to a security management configuration.