A notification indicating that number of PPPoE session count dropped below configured global threshold watermark. There will be only one trap send whenever count drops, further low count won't generate trap. Number of PPPoE sessions count need to cross the watermark and drop below watermark to generate trap again. The configured watermark can be referred through object cPppoeSystemSessionLossThreshold. An agent must not generate more than one cPppoeSystemSessionLossThresholdTrap `trap-event` in a 30 second period, where a `trap-event` is the transmission of a single trap PDU to a list of trap destinations. If the PPPoE session count keep on fluctuating around the watermark during 30 seconds, then these trap-events should be suppressed by agent.