Device type indicates which physical transport and protocol are used to
access the device. The lower 16 bits are interpreted as a bitfield that
is used to specify the type of transport used by the device. The upper
16 bits are interpreted as the protocol used to communicate with a
device of the specified transport type. Please note that specification
of the protocol is optional and if no protocol is specified then
communication with all devices of a particular transport type will be
attempted.