Chapter 1: Overview
34
The PoE power is supplied to the PoE ports on a first come basis. By
default, the highest PoE priority starts from slot 0, port 0 and decreases as
the PoE slot/port numbers ascend to the last PoE port.
For example, if you have one AT-SBx3165 PoE Power Supply and two
AT-SBx31GP24 PoE Line Cards are installed and 40 Class 4 PDs
connected to slot/ports 0/0 through 0/23 and 1/0 through 1/15, they all
receive the full 30 W of PoE power or a total of 1200W. If more than 40
PDs are connected, the highest slot/port numbers have a flashing amber
or fault condition because all the available PoE power (1200 W) are
allocated to the first 39 ports and no additional PoE power is available for
the additional PDs.
Note
The PoE port priorities can be reassigned using the port
configuration commands in the Switchblade x3112 Management
Software. Refer the to the Software Reference for SwitchBlade®
x3100 Series Switches on the ATI web site for specific information.
Go to “Where to Find Web-based Guides” on page 13 for
information about how to navigate to this document.
Table 8. IEEE802.3at Classes versus AT-SBx31GP24 Power Levels
Class Usage
Maximum
Power Levels
Output at the
PoE port
Range of
Power Levels
Available at
the PD Input
Maximum # of
Ports with
1 PoE PSU
(1200 W)
Maximum # of
Ports with
2 PoE PSU’s
(2400 W)
0 Default 15.4W .044W to
12.95W
77 155
1 Optional 4.0W 0.44W to 3.84W 240 240
2 Optional 7.0W 3.84W to 6.49W 171 240
3 Optional 15.4W 6.49W to
12.95W
77 155
4 Optional 30.0W 12.95W to
25.9W
40 80