Patent ID: 7436819

Claim:
A communication apparatus comprising a master phone, a slave phone, a facsimile, a first communication means for telephone communication via a public network using a specified communication cable, and a second communication means for telephone communication via an IP network using the communication cable, the apparatus further comprising: a selection means for selecting one of the first and second communication means based on a user indication; and a control means for, during communication using one of the communication means selected by the selection means, controlling communication using the other communication means based on a user instruction, wherein said selection means selects the first communication means in a case where the user indication indicates to use the master phone, said selection means selects the second communication means in a case where the user indication indicates to use the slave phone, said selection means selects the first communication means in a case where the user indication indicates to use the facsimile, and said selection means selects the second communication means in a case where the user indication indicates to use the second communication means.