38.3.4 Detection of a Loss

Each time a loss is detected by an instance of the class PLMLossMonitor, a call to the Agent/LossMonitor/PLM instproc log-loss is triggered. The Agent/LossMonitor/PLM instproc log-loss is empty. In fact, we define the log-loss instproc for the class PLMLossTrace. The PLMLossTrace instproc log-loss simply calls the PLM instproc log-loss which contains the PLM machinery in case of loss. In summary, log-loss only drops a layer when the loss rate exceeds 10% (this test is executed by the PLM instproc exeed_loss_thresh). After a layer drop log-loss precludes any other layer drop due to loss for 500ms. For details about the PLM instproc log-loss, refer to its code in ~ns/tcl/plm/plm.tcl.

Tom Henderson 2011-11-05