Juniper Networks manual Complete Hardware Guide for EX8208 Ethernet Switches

Complete Hardware Guide for EX8208 Ethernet Switches

•Junos OS Release 10.1 or earlier—Consult Table 17 on page 42, Table 19 on page 43, or Table 20 on page 43 to determine the number of power supplies needed (N). Then multiple the N value by two.

NOTE: In Junos OS Release 10.1 or earlier, the power management feature manages switches for N+1 redundancy only. This means, for example, that power management raises an alarm if there is insufficient power to maintain N+1 redundancy, but not if there is insufficient power to maintain N+N redundancy.

•Junos OS Release 10.2 or later—Consult Table 21 on page 45, Table 23 on page 45, or Table 24 on page 46 in this section.

Starting with Junos OS Release 10.2, you can configure the power management software to manage the switch power for N+N redundancy. When you configure power management for N+N redundancy, power management lowers the maximum chassis power consumption by lowering the maximum fan speed. It does so to compensate for the extra power that is held in reserve in an N+N configuration than in an N+1 configuration, because of which less power would ordinarily be available to power line cards. By reducing the maximum chassis power consumption, power management allows the switch to power more line cards.

The configuration type of the switch and the input voltage determine the number of power supplies needed (N) for the switch. You must then install additional power supplies to meet the N+N redundancy configuration. For details about different switch configurations, see “EX8208 Switch Configurations” on page 6 or EX8216 Switch Configurations.

The tables in this section list the N+N power requirements for different EX8200 switch configurations:

•Table 21 on page 45—Lists the N+N power requirements of EX8208 switch configurations that use 2000 W AC power supplies.

•Table 22 on page 45—Lists the N+N power requirements of EX8208 switch configurations that use 3000 W AC power supplies.

•Table 23 on page 45—Lists the N+N power requirements of EX8216 switch configurations that use 2000 W AC power supplies.

•Table 24 on page 46—Lists the N+N power requirements of EX8216 switch configurations that use 3000 W AC power supplies.

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