Allied Telesis AT-S62 - Manual (Page 321)

AT-S62 Menus Interface User’s Guide
Section II: Advanced Operations 321
connected to it is PoE-compliant or not and, if it is, how much power is
required.
The default setting for PoE on the switch is enabled on all ports.
Port
Prioritization
This section explains port prioritization, a mechanism by which the
switch determines which ports are to receive PoE in the event the needs
of the powered devices exceed the available power resources of the
switch. This discussion does not apply to the AT-8524POE switch since
its power supply can deliver the maximum of 15.4 W to all 24 based
ports simultaneously. This discussion becomes relevant only if, at some
later date, Allied Telesyn releases an AT-8500 Series switch with PoE
capability that has a power supply that might not be able to service all
ports simultaneously.
If the powered devices connected to a switch require more power than
the switch is capable of delivering, the switch will deny power to some
ports based on a system called port prioritization. You can 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
The Critical level is the highest priority level. Ports set to this level are
guaranteed power before any 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. 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 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.