A communication device configured to be connected with a public network and an IP network is provided, the communication device including a communication controller that selectively performs one of a public line communication process via the public network and an IP communication process via the IP network. When determining that a redialing process to reattempt the IP communication process via the IP network is unlikely to be successfully performed, the communication controller performs a fallback process to attempt the public line communication process via the public network after switching from the IP communication process via the IP network to the public line communication process via the public network, in a situation where a setting for performing the fallback process is configured. When determining that the redialing process via the IP network is not unlikely to be successfully performed, the communication controller performs the redialing process.