Allied Telesis AT-x230-10GP, Руководство по установке

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AT-x230-10GT, AT-x230-10GP, AT-x230-18GT, AT-x230-18GP, AT-x230-28GT and AT-x230-28GP Switch Installation Guide
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To determine whether the power requirements of the PoE devices you
plan to connect to the switch exceed its power budget, refer to their
documentation for their power requirements and add the requirements
together. The switch should be able to power all of the devices
simultaneously as long as the total is below its power budget. If the total
exceeds the available power budget, you should consider reducing the
number of PoE devices so that all of the devices receive power.
Otherwise, the switch powers a subset of the devices, based on port
prioritization.
The switch can handle different power requirements on different ports.
This enables you to connect different classes of PoE equipment to the
ports on the switch.
Port
prioritization
If the power requirements of the powered devices exceed the switch’s
power budget, the switch denies power to some ports based on a system
called port prioritization. You may use this mechanism to ensure that
powered devices critical to the operations of your network are given
preferential treatment by the switch in the distribution of power should the
demands of the devices exceed the available capacity.
There are three priority levels:

Critical

High

Low
Ports set to the Critical level, the highest priority level, are guaranteed
power before any of the ports assigned to the other two priority levels.
Ports assigned to the other priority levels receive power only if all the
Critical ports are receiving power. Ports that are connected to your most
critical powered devices should be assigned to this level. If there is not
enough power to support all the ports set to the Critical priority level, power
is provided to the ports based on port number, in ascending order.
The High level is the second highest level. Ports set to this level receive
power only if all the ports set to the Critical level are already receiving
power. If there is not enough power to support all of the ports set to the
High priority level, power is provided to the ports based on port number, in
ascending order.
The lowest priority level is Low. This is the default setting. Ports set to this
level only receive power if all of the ports assigned to the other two levels
are already receiving power. As with the other levels, if there is not enough
power to support all of the ports set to the Low priority level, power is
provided to the ports based on port number, in ascending order.
Power allocation is dynamic. If the switch’s power budget is at its
maximum, ports may stop supplying power to powered devices if new
powered devices, connected to ports with higher priorities, become active.