Power over Ethernet (PoE) means that power sourcing equipment (PSE) supplies power to powered devices (PDs) such as IP telephone, wireless LAN access point, and web camera from Ethernet ports through twisted pair cables.

A PoE device can provide 48 VDC power to its PDs and provide power supply monitoring and PD priority management.

& Note:

Among the interface cards for S9500 Series Routing Switches, the LSB1GV48DB and LSB2GV48DA interface cards support PoE.

I. Advantages

l Reliable: Power is supplied in a centralized way so that it is very convenient to provide a backup power supply.

l Easy to connect: A network terminal requires only one Ethernet cable, but no external power supply.

l Standard: In compliance with IEEE 802.3af, a globally uniform power interface is adopted.

l Promising: It can be applied to IP telephones, wireless LAN access points (APs), portable chargers, card readers, web cameras, and data collectors.

II. Composition

A PoE system consists of PoE power, PSE, and PD.

l PoE power

The whole PoE system is powered by the PoE power, which includes external PoE power and internal PoE power.

l PSE

PSE is an entity used to manage PoE for ports on a card or subcard. The PSEs on cards/subcards manage the PoE interfaces on their own cards/subcards independently. Through the PoE interface cables, a PSE detects PDs, classifies them, supplies power to them, and stops supplying power to a PD when it detects that the PD is removed.

An Ethernet interface with the PoE capability is called a PoE interface. Currently, a PoE interface can be an FE (Fast Ethernet) or GE (Gigabit Ethernet) interface.

l PD

A PD is a device accepting power from a PSE. There are standard PDs and nonstandard PDs. A standard PD refers to the one that complies with IEEE 802.3af. The PD that is being powered by the PSE can be connected to other power supply unit for redundancy backup.

1.1.2 Protocol Specification

The protocol specification related to PoE is IEEE 802.3af.

1.2 PoE Configuration Task List

Complete these tasks to configure PoE:

Task	Remarks
Configuring the PoE Power	Required
Configuring a PSE	Required
Configuring a PoE Interface	Required
Configuring PoE Power Management	Optional
Configuring PoE Monitoring	Optional
Enabling the PSE to Detect Nonstandard PDs	Optional
Displaying and Maintaining PoE	Optional

& Note:

l When the PoE power is shut down or unavailable, all PoE related configuration commands will fail.

l Turning off the PoE power during the startup of the device might result in the failure to restore the PoE configuration.

1.3 Configuring the PoE Power

The maximum PoE power refers to the maximum power that the device can provide for all PSEs. To avoid a power failure to the PSE owing to overload, the power consumption of all PSEs should not exceed the maximum power of the device.

Follow these steps to configure the PoE power:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure the maximum PoE power	poe power max-value max-power	Optional The default maximum PoE power is 1125 for 220 VAC input and 562 for 110 VAC input.

To do…

Use the command…

Remarks

Enter system view

system-view

—

Configure the maximum PoE power

poe power max-value max-power

Optional

The default maximum PoE power is 1125 for 220 VAC input and 562 for 110 VAC input.

& Note:

l In the case of 220 VAC input, when the switch uses single or dual power supply modules, you can set at most 2250 W as the maximum PoE power; when the switch uses triple power modules, you can set at most 4500 W as the maximum PoE power.

l In the case of 110 VAC input, when the switch uses single or dual power supply modules, you can set at most 1125 W as the maximum PoE power; when the switch uses triple power modules, you can set at most 2250 W as the maximum PoE power.

1.4 Configuring a PSE

Follow these steps to configure a PSE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable PoE for a PSE	poe enable pse pse-id	Required By default, PoE is disabled for a PSE.
Configure the maximum PoE power of a PSE	poe max-power max-power pse pse-id	Optional The max-power argument ranges from 37 to 806, in watts. By default, the maximum PoE power of a PSE is 806 W.

& Note:

l Ensure that the sum of maximum power of all the PSEs on the device does not exceed the maximum power of the PoE power. When the remaining power of the PoE power is lower than the maximum power of a PSE, PoE is disabled for the PSE.

l The maximum power of the PSE must be greater than or equal to the sum of maximum power of all critical PoE interfaces on the PSE so as to guarantee the power supply to these PoE interfaces.

l To ensure power supply to the last PD and provide redundant power to prevent sudden increase of the power, 19 watts guard band will be reserved for the interface by default. That is, if the configured maximum power of the PSE is 119 W, the PSE can supply 100 W power to the PD.

l The relation between the ID and slot number of a PSE is: PSE ID = SlotNo × 3 + 1.

1.5 Configuring a PoE Interface

You can configure a PoE interface in either of the following two ways:

l Adopt the command line.

l Configure a PoE configuration file and apply the file to the specified PoE interface(s).

Usually, you can adopt the command line to configure a single PoE interface, and adopt a PoE configuration file to configure multiple PoE interfaces at the same time.

Caution:

You can adopt either mode to configure, modify, or delete a PoE configuration parameter under the same PoE interface.

For the S9500 series, PoE interfaces can only use signal cables to supply power.

1.5.1 Configuring a PoE Interface Through the Command Line

Follow these steps to configure a PoE interface through the command line:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter PoE interface view	interface interface-type interface-number	—
Enable PoE	poe enable	Required By default, PoE is disabled on the PoE interface.
Configure the maximum power for the PoE interface	poe max-power max-power	Optional By default, the maximum power on the PoE interface is 15,400 milliwatts.
Configure the PoE mode for the PoE interface	poe mode signal	Optional By default, the PoE mode is signal (power over signal cables).
Configure a description for the PD connected to the PoE interface	poe pd-description string	Required By default, no description is configured.

1.5.2 Configuring PoE Interfaces Through a PoE Configuration File

A PoE configuration file is used to configure at the same time multiple PoE interfaces with the same attributes to simplify operations. This configuration method is a supplement to the common command line configuration.

Commands in a PoE configuration file are called configurations.

Follow these steps to configure PoE interfaces through a PoE configuration file:

To do…		Use the command…	Remarks
Enter system view		system-view	—
Create a PoE configuration file and enter PoE configuration file view		poe-profile profile-name [ index ]	Required
Enable PoE for the PoE interface		poe enable	Required By default, PoE is disabled on a PoE interface.
Configure the maximum power for the PoE interface		poe max-power max-power	Optional By default, the maximum power on the PoE interface is 15,400 milliwatts.
Configure the PoE mode for the PoE interface		poe mode signal	Optional By default, the PoE mode is signal (power over signal cables).
Return to system view		quit	—
Apply the PoE configuration file to the PoE interface(s)	Apply the PoE configuration file to one or more PoE interfaces	apply poe-profile { index index \| name profile-name } interface interface-range	Use either approach
	Apply the PoE configuration file to the current PoE interface in PoE interface view	interface interface-type interface-number
		apply poe-profile { index index \| name profile-name }

Caution:

l Before you can configure another PoE configuration file on a POE interface, you should first remove the original PoE configuration file applied to the PoE interface; otherwise, your configuration will fail.

l If a PoE configuration file is already applied to a PoE interface, you must execute the undo apply poe-profile command to remove the application to the interface before deleting or modifying the PoE configuration file.

l You must use the same mode (command line or PoE configuration file) to configure the poe max-power and poe priority commands.

1.6 Configuring PoE Power Management

PoE power management involves PSE power management and PD power management.

1.6.1 Configuring PSE Power Management

Where the maximum PoE power may be lower than the sum of the maximum power required by all PSEs, PSE power management is applied to guarantee power supply to important PSE. Where the maximum PoE power of the device is higher than the sum of the maximum power required by all PSEs, it is unnecessary to enable PSE power management.

Power supply to the PSE is subject to PSE power management policies.

When the PoE power supplies power to the PSE,

l By default, no power will be supplied to new PSE when the PoE power is overloaded.

l Under the control of a priority policy, the PSE with a lower priority is first disconnected to guarantee the power supply to the new PSE with a higher priority when the PoE power is overloaded.

The power priority levels of PSE include critical, high and low in descending order.

If the guaranteed remaining PoE power (guaranteed maximum PoE power – power allocated to the critical PSE, regardless of whether PoE is enabled for the PSE) is lower than the maximum power of the PSE, you will fail to set the power priority of the PSE to critical. Otherwise, you can succeed in setting the power priority to critical, and this PSE will preempt the power of the PSE with a lower priority level. In the latter case, the PSE whose power is preempted will be disconnected, but its configuration will remain unchanged. After you change the priority of the PSE from critical to a lower level, other PSEs will have an opportunity of seizing power.

I. Configuration prerequisites

Enable PoE for the PSE.

II. Configuration procedure

Follow these steps to configure PSE power management:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure the power priority for the PSE	poe priority { critical \| high \| low } pse pse-id	Optional By default, the power priority level of the PSE is low.
Configure a PSE power management priority policy	poe pse-policy priority	Optional By default, no PSE power management priority policy is configured.

1.6.2 Configuring PD Power Management

The power priority of a PD depends on the priority of the PoE interface. The priority levels of PoE interfaces include critical, high and low in descending order. Power supply to a PD is subject to PD power management policies.

all PSEs implement the same PD power management policies. When the PSE supplies power to a PD,

l By default, no power will be supplied to a new PD if the PSE power is overloaded.

l Under the control of a priority policy, the PD with a lower priority is first powered off to guarantee the power supply to the new PD with a higher priority when the PSE power is overloaded.

If the guaranteed remaining PSE power (maximum PSE power – power to be allocated to the critical PoE interface, regardless of whether PoE is enabled for the PoE interface) is lower than the maximum power of the PoE interface, you will fail to set the priority of the PoE interface to critical. Otherwise, you can succeed in setting the priority to critical, and this PoE interface will preempt the power of other PoE interfaces with a lower priority level. In the latter case, the PoE interfaces whose power is preempted will be powered off, but their configurations will remain unchanged. When you change the priority of a PoE interface from critical to a lower level, the PDs connecting to other PoE interfaces will have an opportunity of seizing power.

I. Configuration prerequisites

Enable PoE for PoE interfaces.

II. Configuration procedure

Follow these steps to configure PD power management:

To do…		Use the command…	Remarks
Enter system view		system-view	—
Configure the power priority for a PoE interface	Configure the power priority for the PoE interface in PoE interface view	interface interface-type interface-number	Use either approach. By default, the power priority of a PoE interface is low.
		poe priority { critical \| high \| low }
	Configure the power priority for the PoE interface in PoE configuration file view	poe-profile profile-name [ index ]
		poe priority { critical \| high \| low }
Configure a PD power management priority policy		poe pd-policy priority	Optional By default, no PD power management priority policy is configured.

& Note:

l When the PSE power is to be at full load, power is supplied to a new PD based on the priority policy.

l The power priority of all the PoE interfaces is based on the same card. That is, power priority of PoE interfaces on different cards cannot be compared.

1.7 Configuring PoE Monitoring

The PoE monitoring function involves monitoring of PoE power, PSE and PD.

l Monitoring PoE power means monitoring the voltage of the PoE power.

l When the current power utilization of the PSE is above or below the alarm threshold for the first time, the system will send a Trap message.

l When the PSE starts or stops supplying power to a PD, the system will send a Trap message, too.

1.7.1 Configuring PoE Power Monitoring

Follow these steps to configure PoE power monitoring:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure an AC input under-voltage threshold for the PoE power	poe-power input-threshold lower value	Optional The default is: 181 for 220 VAC input 90 for 110 VAC input
Configure an AC input over-voltage threshold for the PoE power	poe-power input-threshold upper value	Optional The default is: 264 for 220 VAC input 132 for 110 VAC input
Configure a DC output under-voltage threshold for the PoE power	poe-power output-threshold lower value	Optional The default is 45.
Configure a DC output over-voltage threshold for the PoE power	poe-power output-threshold upper value	Optional The default is 57.

Caution:

l The under-voltage threshold should be less than the over-voltage threshold.

l You are recommended to use the default threshold when configuring under/over-threshold, unless you have specific needs.

1.7.2 Configuring a Power Alarm Threshold for a PSE

Follow these steps to configure a power alarm threshold for a PSE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure a power alarm threshold for a PSE	poe utilization-threshold utilization-threshold-value pse pse-id	Optional By default, the power alarm threshold for a PSE is 80%.

To do…

Use the command…

Remarks

Enter system view

system-view

—

Configure a power alarm threshold for a PSE

poe utilization-threshold utilization-threshold-value pse pse-id

Optional

By default, the power alarm threshold for a PSE is 80%.

1.8 Enabling the PSE to Detect Nonstandard PDs

There are standard PDs and nonstandard PDs. Usually, the PSE can detect only standard PDs and supply power to them. The PSE can detect nonstandard PDs and supply power to them only after the PSE is enabled to detect nonstandard PDs.

Follow these steps to enable the PSE to detect nonstandard PDs:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable the PSE to detect nonstandard PDs	poe legacy enable pse pse-id	Optional By default, the PSE is disabled from detecting nonstandard PDs.

To do…

Use the command…

Remarks

Enter system view

system-view

—

Enable the PSE to detect nonstandard PDs

poe legacy enable pse pse-id

Optional

By default, the PSE is disabled from detecting nonstandard PDs.

1.9 Displaying and Maintaining PoE

To do…	Use the command…	Remarks
Display the mapping between ID, module, and slot of all PSEs.	display poe device	Available in any view
Display the power state and information of the specified PoE interface	display poe interface [ interface-type interface-number ]	Available in any view
Display the power information of a PoE interface(s)	display poe interface power [ interface-type interface-number ]	Available in any view
Display the power information of the PoE power and all PSEs	display poe power-usage	Available in any view
Display the information of PSE	display poe pse [ pse-id ]	Available in any view
Display the power state and information of all PoE interfaces connected with the PSE	display poe [ pse pse-id ] interface	Available in any view
Display the power of all PoE interfaces connected with the PSE	display poe [ pse pse-id ] interface power	Available in any view
Display information of the PoE power	display poe-power	Available in any view
Display the state information of the AC input power	display poe-power ac-input state	Available in any view
Display the alarm information of the PoE power	display poe-power alarm	Available in any view
Display the state information of the DC output power	display poe-power dc-output state	Available in any view
Display the parameter values of the DC output power	display poe-power dc-output value	Available in any view
Display the status information of the PoE power	display poe-power status	Available in any view
Display the information of the monitoring module of the PoE power	display poe-power supervision-module	Available in any view
Display the switch information of the PoE power	display poe-power switch state	Available in any view
Display all information of the configurations and applications of the PoE configuration file	display poe-profile [ index index \| name profile-name ]	Available in any view
Display all information of the configurations and applications of the PoE configuration file applied to the specified PoE interface	display poe-profile interface interface-type interface-number	Available in any view

1.10 PoE Configuration Example

I. Network requirements

l The device is equipped with two PoE-supporting cards, which are inserted in slot 3 and slot 5 respectively.

l Allocate 400 watts to the card in slot 3 and full power to the card in slot 5 to guarantee normal power supplying to all PSEs.

l GigabitEthernet 3/1/1 and GigabitEthernet 3/1/2 are connected to IP telephones.

l GigabitEthernet 5/1/1 and GigabitEthernet 5/1/2 are connected to AP devices.

l The power priority of GigabitEthernet 3/1/2 is critical.

l The power of the AP device connected to GigabitEthernet 5/1/1 cannot exceed 9,000 milliwatts.

II. Network diagram

Figure 1-1 Network diagram for PoE

III. Configuration procedure

# Enable PoE for the PSE.

<Sysname> system-view

[Sysname] poe enable pse 10

[Sysname] poe enable pse 16

# Set the maximum power for the card in slot 3 to 400 watts. You do not need to configure the maximum power for the card in slot 5 because it is full by default.

[Sysname] poe max-power 400 pse 10

# Enable PoE on GigabitEthernet 3/1/1, GigabitEthernet 3/1/2, GigabitEthernet 5/1/1, and GigabitEthernet 5/1/2.

<Sysname> system-view

[Sysname] interface gigabitethernet 3/1/1

[Sysname-GigabitEthernet3/1/1] poe enable

[Sysname-GigabitEthernet3/1/1] quit

[Sysname] interface gigabitethernet 3/1/2

[Sysname-GigabitEthernet3/1/2] poe enable

[Sysname-GigabitEthernet3/1/2] quit

[Sysname] interface gigabitethernet 5/1/1

[Sysname-GigabitEthernet5/1/1] poe enable

[Sysname-GigabitEthernet5/1/1] quit

[Sysname] interface gigabitethernet 5/1/2

[Sysname-GigabitEthernet5/1/2] poe enable

[Sysname-GigabitEthernet5/1/2] quit

# Set the power priority level of GigabitEthernet 3/1/2 to critical.

<Sysname> system-view

[Sysname] interface gigabitethernet 3/1/2

[Sysname-GigabitEthernet3/1/2] poe priority critical

[Sysname-GigabitEthernet3/1/1] quit

# Set the maximum power of GigabitEthernet 5/1/1 to 9,000 milliwatts.

[Sysname] interface gigabitethernet 5/1/1

[Sysname-GigabitEthernet5/1/1] poe max-power 9000

After the configuration takes effect, the IP phone and AR device are powered and can work normally.

1.11 Troubleshooting PoE

Symptom: Setting the priority of a PoE interface to critical fails.

Analysis:

l The guaranteed remaining power of the PSE is lower than the maximum power of the PoE interface.

l The priority of the PoE interface is already set.

Solution:

l In the former case, you can solve the problem by increasing the maximum PSE power, or by reducing the maximum power of the PoE interface when the guaranteed remaining power of the PSE cannot be modified.

l In the latter case, you should first remove the priority already configured.

Symptom: Applying a PoE configuration file to a PoE interface fails.

Analysis:

l Some configurations in the PoE configuration file are already configured.

l Some configurations in the PoE configuration file do not meet the configuration requirements of the PoE interface.

l A PoE configuration file is already applied to the PoE interface.

Solution:

l In case 1, you can solve the problem by removing the original configurations of those configurations.

l In case 2, you need to need to modify some configurations in the PoE configuration file.

l In case 3, you need to remove the application of the undesired PoE configuration file to the PoE interface.

Symptom: Provided that parameters are valid, configuring an AC input under-voltage threshold fails.

Analysis:

The AC input under-voltage threshold is greater than or equal to the AC input over-voltage threshold.

Solution:

You can drop the AC input under-voltage threshold below the AC input over-voltage threshold.

H3C S9500 Operation Manual-Release2132[V2.03]-08 System Volume

1.1 PoE Overview

1.1.1 Introduction to PoE

I. Advantages

II. Composition

1.4 Configuring a PSE

1.5 Configuring a PoE Interface

1.5.1 Configuring a PoE Interface Through the Command Line

1.6 Configuring PoE Power Management

I. Configuration prerequisites

II. Configuration procedure

I. Configuration prerequisites

II. Configuration procedure

1.7 Configuring PoE Monitoring

1.8 Enabling the PSE to Detect Nonstandard PDs

1.9 Displaying and Maintaining PoE

I. Network requirements

II. Network diagram

III. Configuration procedure

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