In this paper, we evaluate link-state update triggers in wavelength-routed networks. We consider two popular triggers, namely the Absolute Threshold Trigger and the Relative Threshold Trigger. The blocking performance of the two triggers is confirmed to be highly dependent on traffic load. Moreover, it is observed that under light traffic load, blocking performance degrades significantly once the threshold is shifted away from advertising every single link state change immediately. We expect that the above observation would be of significant importance and would impose a critical challenge to the future development of link-state update methods.