Allied Telesis AT-S99 - Manual (Page 52)

Chapter 2: AT-CM and AT-CV Media Converter Line Cards
52
Dying Gasp
Feature
Dying gasp is a signal that AT-CM Line Cards in the AT-CV1203 Chassis
transmit if the chassis has a power failure. This feature can make it easier
to identify power supply or power source problems at remote sites.
If a remote AT-CV1203 Chassis loses power, the AT-CM Line Card in the
chassis transmits the dying gasp signal from Port A over its fiber optic link
to its line card counterpart in the AT-CV5000 Chassis at the central office.
The local card sends the signal over the chassis’ backplane to the
management card which enters the event in its event log and sends an
SNMP trap to alert you to the problem. Figure 7 illustrates the sequence of
events of this feature.
Figure 7. Dying Gasp Feature
If the remote AT-CV1203 Chassis has two AT-CM Line Cards, both cards
transmit the signal from their fiber optic ports.
If the AT-CV1203 Chassis has both a primary power supply and a
redundant power supply, the dying gasp feature can notify you if one
power supply loses power. It accomplishes this by sending the “1st RPS
Failure” signal. This signal indicates that the remote chassis has lost
power on one power supply, but continues to operate with the remaining
power supply.
To support this feature, there has to be an AT-CV5M02 Management Card
installed in the remote chassis because only a management card can
detect the loss of a single power supply when a chassis has two power
supplies. This feature is illustrated in Figure 8.
FAN1
PS1
RDY
A T -CV5000
1. The remote AT-CV1203
Chassis loses power.
2. The remote AT-CM Card Line
Card sends the dying gasp
signal to its local counterpart in
the AT-CV5000 Chassis.
3. The local AT-CM Line Card
sends the signal over the
backplane to the management
card.
4. The management card enters
the event in the event log and
sends an SNMP trap.