device-name[:]

    Optional. Indicates the name of a device over which the network
    connection occurred. The device name has the form ddcu where dd
    is the device code, c is the controller designation, and u is the
    unit number. LAN devices are specified as the name of the device
    that is unit 0. For example, the first terminal device on a LAN
    is specified as TTA0, the second as TTB0.