PairGain PG-Flex, Руководство пользователя

Страница: 23 / 168

Faults
15
Faults
A fault on any unit shall be an indication of an abnormal condition that affects the functionality or
performance of the unit itself or any units under its control. That is, a fault on an RT channel unit
shall be indicated on the channel unit itself, propagated to the upstream RT line unit, and reported
as a fault against the RT channel unit.
There are situations when the unit is incapable of propagating any information about the fault
upstream (that is, losing communications with an upstream unit). The respective line unit shall then
determine that such a condition exists and indicate a fault condition against the lower level unit. In
this example, a major alarm would also be generated.
Propagation of the fault condition up to and including the COT line unit is the responsibility of the
respective RT line unit. The exception to this would be the HDSL Faults which are normally passed
to the COT line unit with the normal HDSL performance monitoring information.
A fault may cause the following alarms: Major, Minor, Information Alarms, or none, depending on
how the system is configured.
The line unit detecting a Major, Minor, or Information Alarm logs the fault in its local fault history
database. The database is accessible from either the CO or RT line unit node in the system. As a
minimum, the database for each fault includes:
• fault type
• date and time of the first occurrence since the database was last cleared or from power on
• date and time of the most recent occurrence
• current alarm status
• number of occurrences
The minimum logging rate is at a once a second rate.