An indication of the type of device.
If this value is
`hrDeviceProcessor { hrDeviceTypes 3 }' then an entry
exists in the hrProcessorTable which corresponds to
this device.
If this value is
`hrDeviceNetwork { hrDeviceTypes 4 }', then an entry
exists in the hrNetworkTable which corresponds to this
device.
If this value is
`hrDevicePrinter { hrDeviceTypes 5 }', then an entry
exists in the hrPrinterTable which corresponds to this
device.
If this value is
`hrDeviceDiskStorage { hrDeviceTypes 6 }', then an
entry exists in the hrDiskStorageTable which
corresponds to this device.