Patent ID: 7688791

Claim:
A communications apparatus comprising: a network connection unit configured to connect to a network to participate in the network upon the occurrence of a predetermined event; and a control unit configured to control the communications apparatus to transmit a first message onto the network before a second message is transmitted from the communications apparatus onto the network, when the network connection unit connects to the network to participate in the network upon the occurrence of the predetermined event, wherein the control unit controls the communications apparatus to transmit the second message onto the network after the first message is transmitted from the communications apparatus onto the network, wherein the first message is used to notify an external device on the network that the communications apparatus is separated from the network so that the external device deletes device specific information of the communications apparatus from a device management table managed by the external apparatus, and the second message is used to notify the external device on the network that the communications apparatus is participating in the network so that the external device registers device specific information of the communications apparatus in the management table after the device specific information has been deleted based on the first message.