The following table lists the over-temperature thresholds for 7210 SAS devices.
Device variants |
Minimum temperature (in degrees centigrade) |
Maximum temperature (in degrees centigrade) |
|---|---|---|
7210 SAS-Mxp |
0 |
76 |
7210 SAS-Mxp ETR |
-10 |
80 |
7210 SAS-R6 |
-1 |
74 |
7210 SAS-R12 |
0 |
96 |
7210 SAS-Sx/S 1/10GE and 7210 SAS-Sx 10/100GE |
0 |
85 |
7210 SAS-T |
0 |
58 |
7210 SAS-T ETR |
-21 |
68 |
The 7210 SAS system software controls the fans by monitoring the internal temperature of the chassis. The software manages the fan speed to maintain the internal temperature within operational limits.
The 7210 SAS-R6 supports overheat protection reboot. This feature protects the IMM and CPM cards when the temperature exceeds system-defined temperature thresholds; these thresholds are not user-configurable. The software monitors the temperature of each card and if the temperature exceeds the threshold, the system raises an over-temperature critical event. The system reboots all overheated CPM cards and powers off all overheated IMM cards to reduce the heat generated, which consequently cools down the chassis. The system powers back on the IMM cards after the temperature is reduced. Operators are still required to take immediate action for an over-temperature critical event. See the 7210 SAS-R6 Chassis Installation Guide for more information about maintaining the operating temperature.
Nokia recommends that when planning their availability design, operators must consider CPM card reboot handling that is caused when the system temperature exceeds system-defined thresholds. Failure to build in network redundancy may result in network and service downtime.