def show_link(self):
        '''show link information'''
        for master in self.mpstate.mav_master:
            linkdelay = (self.status.highest_msec - master.highest_msec)*1.0e-3
            if master.linkerror:
                print("link %u down" % (master.linknum+1))
            else:
                print("link %u OK (%u packets, %.2fs delay, %u lost, %.1f%% loss)" % (master.linknum+1,
                                                                                      self.status.counters['MasterIn'][master.linknum],
                                                                                      linkdelay,
                                                                                      master.mav_loss,
                                                                                      master.packet_loss()))
show link information