US Patent 7848768 Network system and communication device

A network system includes at least first and second communication devices connected in a network. The first communication device includes an inquiry device for inquiring the attributes of the second communication device to the second communication device via the network. The second communication device includes an attribute holding device for holding the attributes and a search device for searching for the attributes held in the attribute holding device in response to the inquiry and responds back with the search result to the inquiry device. The attribute holding device and the search device operate in a data link layer.