Extreme Networks ExtremeWare XOS 11.1, Руководство пользователя

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ExtremeWare XOS 11.1 Concepts Guide
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6 Power Over Ethernet
Power over Ethernet (PoE) is an effective method of supplying 48 VDC power to certain types of
powered devices (PDs) through Category 5 or Category 3 twisted pair Ethernet cables. PDs include
wireless access points, IP telephones, laptop computers, web cameras, and other devices. With PoE, a
single Ethernet cable supplies power and the data connection, reducing costs associated with separate
power cabling and supply.
This chapter covers the following topics:
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Summary of PoE Features on page 103
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Power Checking for PoE Module on page 103
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Power Delivery on page 104
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LEDs on page 108
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Configuring PoE on page 108
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Displaying PoE Settings and Statistics on page 113
Summary of PoE Features
The Aspen G48P module supports the following PoE features:
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Configuration and control of the power distribution for PoE at the system, slot, and port levels
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Real-time discovery and classification of 802.3af-compliant PDs and many legacy devices
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Monitor and control of port PoE fault conditions including exceeding configured power limits and
short-circuit detection
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Support for configuring and monitoring PoE status at the system, slot, and port levels
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Management of an over-subscribed power budget
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Port LED control for indicating the link state
For detailed information on using the PoE commands to configure, manage, and display PoE settings,
refer to the
ExtremeWare XOS Command Reference Guide.
Power Checking for PoE Module
PoE modules require more power than other I/O modules. When a chassis containing a PoE module is
booted or a new PoE module is inserted, the power drain is calculated. Before the PoE module is
powered up, the chassis calculates the power budget and powers up the PoE module only if there is
enough power. The chassis powers up as many I/O modules as possible with lower-numbered slots
having priority.