Power over Ethernet (PoE) uses 10BaseT,
100Base-TX, and 1000Base-T twisted pairs to supply power to the remote powered devices
(PD) in the network and implement power supply and data transmission
simultaneously.
I. Advantages
of PoE
l
Reliability: The centralized power supply
provides backup convenience, unified management, and safety.
l
Easy connection: Network terminals only require
an Ethernet cable, but no external power supply.
l
Standard: PoE conforms to the 802.3af standard
and uses a globally uniform power interfaces;
l
Bright application prospect: PoE can be applied
to IP phones, wireless access points (APs), chargers for portable devices, card
readers, cameras, and data collection.
II. PoE
components
l
Power sourcing equipment (PSE): PSE is comprised
of the power and the PSE functional module. It can implement PD detection, PD
power information collection, PoE, power supply monitoring, and power-off for
devices.
l
PD: PDs receive power from the PSE. PDs include
standard PDs and nonstandard PDs. Standard PDs conform to the 802.3af standard,
including IP phones, WLAN APs, network cameras and so on.
l
Power interface (PI): PIs are RJ45 interfaces
which connect PSE/PDs to network cables.
S7500 Series Ethernet Switches (hereinafter
referred to as S7500 series) support PoE. Equipped with external power supply
and PoE-enabled boards, S7500 series can provide -48 VDC power to remote
powered devices (PDs) through twisted pairs.
l
The S7500 series support IEEE802.3af standard.
While they can also supply power to PDs noncompliant with the standard.
l
The power supply of the S7500 series is
administered by the main control board; each PoE board on the switch can be
viewed as a power sourcing equipment (PSE) and administers the power supply of
all the ports on it independently.
l
The S7500 series can deliver data and current
simultaneously through data wires (1, 3, 2, and 6) of category-3/5 twisted
pairs.
l
The S7500 series supply power through the
Ethernet electrical ports on the service boards. Each service board can supply
power to up to 48 remote devices at the maximum distance of 100 m (328 feet).
l
Each Ethernet port can supply at most a power of
15.4 W to remote PDs.
l
When the S7500 series supply power to remote
devices, the maximum total power that it can provide is 2,400 W. The switch
determines whether or not to supply power to the next remote PD it discovers
depending on the total power it currently supplies.
l When the PoE-enabled S7500 series supply power
to remote PDs, the PDs need not have any external power supply.
l If a remote PD has an external power supply, the
PoE-enabled S7500 series and the external power supply will be redundant with
each other for the PD.
If PSE2500-A1 power system is taken as the
external power supply, the power is distributed as follows:
1)
Input voltage: 100 VAC to 140 VAC
l
One power supply unit (PSU) of the PSE2500-A1
power system can supply 1,250 W of power, and two PSUs can supply up to 2,400 W
of power.
l
If the PSUs of PSE2500-A1 power system need to
work in redundancy mode, three PSUs are required and they work together to
supply 2,400 W of power.
2)
Input voltage: 200 VAC to 240 VAC
l
One PSU of the PSE2500-A1 power system can
supply 2,500 W of power.
l
If the PSUs of PSE2500-A1 power system need to
work in redundancy mode, two PSUs are required.
The following boards of S7500 series
support PoE:
l
LS81FT48F
l
LS81GT48A
S7500 series manage PoE in either auto mode
or manual mode. Through the setting of the management and PoE priority, the
switch determines whether to supply power to newly added PDs when the power
supply is almost fully-loaded.
l
auto mode: When
the switch is reaching its full load in supplying power, it will first supply
power to the PDs that are connected to the ports with critical priority, and
then supply power to the PDs that are connected to the ports with high
priority. For example: port A is of critical priority. When the switch is
reaching its full load and a new PD is now added to port A, the switch will
power down the PD connected to a port with lower priority and turn to supply
power to this new PD.
l
manual mode: When
the switch is reaching its full load in supplying power, it will neither take
the priority into account nor make change to its original power supply state.
For example: Port A has the priority critical. When the switch is reaching its
full load and a new PD is now added to port A, the switch will not supply power
to this new PD.
In auto
mode, when the switch is reaching its full load in supplying power, the switch
decides whether to supply power to remote PDs on a port based on the port
priority. Note that the switch can compare only the priority of ports on the
same board.
Table 1-1 PoE configuration tasks
Table 1-2 Configure the PoE feature on a port
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Configure the maximum
PoE power that a switch can supply
|
poe power max-value max-value
|
Optional
By default, the
maximum PoE power that a switch can supply is 2,400 W.
|
When setting the
maximum PoE power supplied by the switch with the poe power max-value
command, you must set it to a value greater than the total power that has been
distributed to the boards. Otherwise, this command cannot be executed
successfully. The maximum power that a switch can supply ranges from 37 W to
2,400 W.
Table 1-3
Configure the PoE feature of a
PoE-enabled board
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Set the PoE
management mode of the switch
|
poe power-management { auto | manual } slot slot-number
|
Optional
By default, the
switch manages PoE in the manual mode.
|
|
Enable the PoE
feature of the board
|
poe enable slot slot-number
|
Optional
By default, the PoE
feature is disabled on a board.
|
|
Set the maximum power
that the board can supply
|
poe max-power max-power slot slot-number
|
Optional
By default, a board
provides up to 37W of power.
|
|
Enable the
compatibility detection feature for remote PDs of the board
|
poe legacy enable slot slot-number
|
Optional
By default,
compatibility detection is disabled for PDs.
|
l
You can successfully enable PoE on a board only
when the remaining power of the switch is not less than the full power of this
board.
l
The required power of PDs may exceed the power
configured for them due to their unstable status, thus causing the PDs
connected to the last port on the board to be powered off. Therefore, when you
configure the maximum power value for a board, ensure enough power for all
ports of the board and reserve additional 20 W power for instant high power at
the same time.
l
Once PoE is enabled on a board, the system
reserves the power for the slot even after you remove the board from the slot;
in this case, you can use the undo poe enable slot command to release
this power.
l
The reserved power for a blank slot will be
recycled automatically by the system if you insert a PoE-incapability board
into the slot. The reserved power for a blank slot will still be distributed to
the slot if you insert a different type of board into the slot and the board is
PoE-enabled.
l
Before you enable the PoE-compatibility
detection on a board, you must first enable PoE on this board with the poe
enable slot slot-num command.
l
When PoE-compatibility detection is performed on
non-standard devices, the system performance will be affected. When standard
802.3af devices are connected to the board, you are not recommended to enable
the PoE-compatibility detection feature.
Table 1-4 Set the PoE management mode and PoE priority of a port
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Enter Ethernet port
view
|
interface interface-type interface-number
|
—
|
|
Enable the PoE
feature
|
poe enable
|
Required
By default, the PoE
feature is enabled on a port when the PoE feature is enabled on a board.
|
|
Set the maximum power
supplied by the port
|
poe max-power max-power
|
Optional
By default, the maximum
power supplied by the port is 15.4 W.
|
|
Set the power supply
mode of the port
|
poe mode { signal | spare
}
|
Optional
The S7500 series
support only the signal mode.
|
|
Se the PoE priority
of the port
|
poe priority { critical | high | low }
|
Optional
By default, the PoE
priority of the port is low
|
l
The S7500 series do not support the spare
mode.
l
When a board is almost fully loaded and a new PD
is added, the switch will respond to the PD according to the PoE management
mode. For details, see 1.1.5 Setting PoE Management Mode.
l
In auto mode, when the switch is reaching
its full load in supplying power, the switch decides whether to supply power to
remote PDs on a port based on the port priority. Note that the switch can
compare only the priority of ports on the same board.
1.2.5 Upgrading the PSE Processing
Software Online
The online upgrading of
PSE processing software can update the processing software or repair the
software if it is damaged. After downloading the PSE processing software to the
Flash of the switch, you can perform the following configuration. Refer to
“File System Management” for how to download the PSE processing
software.
Table 1-5 Upgrade PSE processing software online
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Upgrade the PSE
processing software online
|
poe upgrade { refresh | full } filename
|
Required
|
l The refresh update mode is to upgrade the
valid software in the PSE through refreshing the software, while the full
update mode is to delete the invalid software in PSE completely and then reload
the software.
l Generally, the refresh update mode is
used to upgrade the PSE processing software.
l When the PSE processing software is damaged
(that is, all the PoE commands cannot be successfully executed), you can use
the full update mode to upgrade and restore the software.
l When the upgrading procedure in refresh
update mode is interrupted for some unexpected reason (such as power-off) or
some errors occur, if the upgrade in full mode fails after restart, you
must upgrade in full mode after power-off and restart of the device. In
this way, the upgrade procedure succeeds.
After the above
configuration, execute the display command in any view to see the
operation of the PoE feature and verify the configuration.
Table 1-6
Display and maintain PoE
|
Operation
|
Command
|
Description
|
|
Display the PoE status of a specific port or all ports of
the switch
|
display
poe interface { interface-type
interface-number | all }
|
You can execute the display command in any view
|
|
Display the PoE power information of a specific port or
all ports of the switch
|
display
poe interface power { interface-type
interface-number | all }
|
|
Display the PSE parameters
|
display poe powersupply
|
|
Display the power supply status of each board and the
power that the board supplies
|
display
poe pse
|
1.4 PoE Configuration
Example
I. Networking
requirements
l
Two PoE-enabled boards are installed in slot 3
and 5 on an S7506 switch.
l
Online upgrade the PSE processing software of
the PoE board in slot 5 of the S7506 switch.
l
Ethernet3/0/1 to Ethernet3/0/48 are connected
with IP phones and Ethernet5/0/1 to Ethernet5/0/48 are connected with access
point (AP) devices.
l
The IP phones are connected to Ethernet3/0/1
through Ethernet3/0/48, and access point (AP) devices are connected to
Ethernet5/0/1 through Ethernet5/0/48.
l
PoE need not be enabled on the IP phones
connected to Ethernet3/0/1 and Ethernet3/0/48.
l
Ethernet3/0/48 requires high priority.
l
Set the PoE management mode of slot 3 to auto.
l
Slot 3 is supplied with 400 W of power and slot
5 is supplied with full power (namely, 806 W).
l
Enable PoE-compatibility detection on the PoE
board in slot 3.
l
The input power of the AP device connected the
Ehternet5/0/15 port cannot be greater than 9 W.
II. Networking
diagram
Figure
1-1 Network diagram for PoE
III. Configuration
procedure
# Enter system view.
<H3C>system-view
# Online upgrade the PSE processing software of the PoE board in slot
5 of the S7506 switch.
[H3C] poe upgrade refresh
0400_001.S19
# Enable the PoE
feature on the boards in slot 3 and slot 5.
[H3C] poe enable slot 3
[H3C] poe enable slot 5
# Set the PoE
management mode on slot 3 to auto.
[H3C] poe power-management auto slot 3
# Set the maximum power supplied by the
board in slot 3 to 400 W.
[H3C] poe max-power 400 slot 3
# Set the maximum power supplied by the
board in slot 5 is 806 W (full power).
[H3C] poe max-power 806 slot 5
# Disable the PoE feature on Ethernet3/0/23
and Ethernet3/0/24.
[H3C]interface Ethernet 3/0/23
[H3C-Ethernet3/0/23] undo poe enable
[H3C-Ethernet3/0/23] quit
[H3C]interface Ethernet 3/0/24
[H3C-Ethernet3/0/24] undo poe enable
[H3C-Ethernet3/0/24] quit
# Set the priority of Ethernet3/0/48 to
critical, so that the devices connected to Ethernet3/0/48 can be provided with
power preferentially without interrupting power supply to the current ports.
[H3C]interface Ethernet 3/0/48
[H3C-Ethernet3/0/48] poe priority
critical
# Enable the PoE-compatibility detection
feature on the board in slot 3.
[H3C] poe legacy enable slot 3
# Set the maximum PoE power supplied by
Ethernet5/0/15 to 9 W.
[H3C] interface Ethernet5/0/15
[H3C-Ethernet5/0/15] poe max-power
9000
The PoE-enabled S7500 series can monitor
the external PoE power supply units (PSUs) through SRPUs.
Table 2-1
PoE PSU supervision configuration tasks
The PSE performance
will be affected by fast switching of PoE PSUs. The interval of switching PoE
PSUs must be no less than 5 seconds.
2.2 AC Input Alarm Thresholds Configuration
You can set the AC input alarm thresholds
for the PoE PSUs to enable the S7500 series to monitor the AC input voltages of
the PSUs in real time through SRPUs.
Table 2-2 Configure AC input alarm
thresholds
|
Item
|
Command
|
Description
|
|
Enter the system view
|
system-view
|
—
|
|
Set the overvoltage alarm threshold of AC
input (upper threshold) for the PoE PSUs
|
poe-power input-thresh upper string
|
Required, and the max voltage is 264.0 V.
|
|
Set the undervoltage alarm threshold of
AC input (lower threshold) for the PoE PSUs
|
poe-power input-thresh lower string
|
Required, and the min voltage is 90.0 V.
|
l
You can set the thresholds to any appropriate
values in the range, but make sure the lower threshold is less than the upper
threshold.
l
For 220 VAC input, it is recommended to set the
upper threshold to 264.0 V and the lower threshold to 181.0 V.
l
For 110 VAC input, you are recommended to set
the upper threshold to 132.0 V and the lower threshold to 90.0 V.
I. Network requirements
l
Set the overvoltage alarm threshold of AC input
for PoE PSUs to 264.0 V.
l
Set the undervoltage alarm threshold of AC input
for PoE PSUs to 181.0 V.
II. Configuration
procedure
# Enter the system view.
<H3C> system-view
# Set the overvoltage alarm threshold of AC
input for PoE PSUs to 264.0 V.
[H3C] poe-power input-thresh upper
264.0
# Set the undervoltage alarm threshold of
AC input for PoE PSUs to 181.0 V.
[H3C] poe-power input-thresh lower
181.0
# Display the AC input state of the PoE
PSUs.
[H3C] display poe-power ac-input
state
You can set the DC output alarm thresholds
for the PoE PSUs to enable the S7500 series to monitor the DC output voltages
of the PSUs in real time through SRPUs.
Table 2-3 DC output alarm thresholds
configuration task
|
Operation
|
Command
|
Description
|
|
Enter the system view
|
system-view
|
—
|
|
Set the overvoltage alarm threshold of DC
output (upper threshold) for the PoE PSUs
|
poe-power output-thresh upper string
|
Required
You are recommended to set the upper threshold
to 47 V when 220 VAC or 110 VAC is input.
|
|
Set the undervoltage alarm threshold of
DC output (lower threshold) for the PoE PSUs
|
poe-power output-thresh lower string
|
Required
You are recommended to set the lower
threshold to 55 V when 220 VAC or 110 VAC is input.
|
I. Network requirements
l
Set the overvoltage alarm threshold of DC output
for the PoE PSUs to 55.0 V.
l
Set the undervoltage alarm threshold of DC
output for the PoE PSUs to 47.0 V.
II. Configuration
procedure
# Enter the system view.
<H3C> system-view
# Set the overvoltage alarm threshold of DC
output for the PoE PSUs to 55.0 V.
[H3C] poe-power output-thresh upper
55.0
# Set the undervoltage alarm threshold of
DC output for the PoE PSUs to 47.0 V.
[H3C] poe-power output-thresh lower
47.0
# Display the DC output state of the PoE
PSUs.
[H3C] display poe-power dc-output
state
# Display the DC output voltage/current
values of the PoE PSUs.
[H3C] display poe-power dc-output
value
After the above configuration, you can
execute the display commands in any view to display the PoE operation of
the switch and verify the configuration.
Table 2-4 Display PoE supervision
information
|
Operation
|
Command
|
Description
|
|
Display the basic information about the
external PoE PSUs.
|
display supervision-module information
|
You can execute the display
command in any view
|
|
Display alarm information about the PoE
PSUs.
|
display poe-power alarm
|
|
Display the number and state of the AC
power distribution switches in the external PoE PSUs.
|
display poe-power switch state
|
|
Display the AC input state of the
external PoE PSUs
|
display poe-power ac-input state
|
|
Display the DC output of the external PoE
PSUs
|
display poe-power dc-output state
|
|
Display the DC output voltage/current
values of the external PoE PSUs
|
display poe-power dc-output value
|
For details about output information, refer
to the Command Manual.
2.5 PoE PSU
Supervision Configuration Example
I. Network requirements
l
Insert a PoE-enabled board into slot 3 of the
S7500 series.
l
Connect IP phones to Ethernet3/0/1 through
Ethernet3/0/48.
l
Set the AC input and DC output alarm thresholds
to appropriate values.
II. Network diagram
Figure 2-1 Network diagram for PoE
supervision configuration
III. Configuration
procedure
# Enter the system view.
<H3C> system-view
# Enable PoE on the board in slot 3.
[H3C] poe enable slot 3
# Set the overvoltage alarm threshold of AC
input for the PoE PSUs to 264.0 V.
[H3C] poe-power input-thresh upper
264.0
# Set the undervoltage alarm threshold of
AC input for the PoE PSUs to 181.0 V.
[H3C] poe-power input-thresh lower
181.0
# Set the overvoltage alarm threshold of DC
output for the PoE PSUs to 55.0 V.
[H3C] poe-power output-thresh upper
55.0
# Set the undervoltage alarm threshold of
DC output for the PoE PSUs to 47.0 V.
[H3C] poe-power output-thresh lower
47.0
