A communication apparatus as one of first communication apparatuses belonging to a first communication network, for communicating with another of the first communication apparatuses via the first communication network, and with one or more second communication apparatuses via a second communication network, the communication apparatus as the one first communication apparatus including a communication portion which communicates with the different first communication apparatus via the first communication network, and with the one or more second communication apparatuses via the second communication network, and a control portion which controls the communication portion to communicate with the different first communication apparatus via the first communication network, in a first control manner, and controls the communication portion to communicate with the one or more second communication apparatuses via the second communication network, in a second control manner different from the first control manner.