Users Guide

Power over Ethernet (PoE)

The PoE feature supports electrical power and transmission of data on Ethernet cabling. A single cable can

provide both data connection and electrical power to the attached devices such as wireless access points or

IP cameras.

Power over Ethernet (PoE), as described by IEEE 802.3af specifies that a maximum of 15.4 watts can be

transmitted to Ethernet devices over the signal pairs of an unshielded twisted pair (UTP) cable. PoE is useful in

networks with IP phones and wireless access points because separate power supplies for powered devices

(PD) are not needed. Power over Ethernet Plus (PoE+), as described by IEEE 802.3at, supplies a maximum of

30.0 watts. This provides sufficient power for devices that require 12.95W to 25.5W, such as pan-tilt-zoom

(PTZ) security cameras, 802.11n Wi-Fi Access Points, and IP phones with advanced features, such as video

conferencing.

The following table describes the classes of powered devices defined by IEEE 802.3af and 802.3at:

Table 50. Classes of Powered Devices

Class Power Range (Watts) Classification Current (MA)

0 0.44 to 12.95 <5.0

1 0.44 to 3.84 10.5

2 3.84 to 6.49 18.5

3 6.49 to 12.95 28

PoE+ Only

4 12.95 to 25.5 40

NOTE: Class 4 is meant for IEEE802.3at compliant devices which require >12.95 Watts. Class 4 devices

will be supported by PoE card, but the maximum power is limited to 15W.

In the S3100 series, the platforms S3124P and S3148P support PoE/PoE+ with the following power options:

• S3124P PSU: 715W, DC output 54V/13.24A or 1100W, DC output 54V/20.37A

• S3148P PSU: 1100W, DC output 54V/20.37A,

Topics:

• Configuring PoE or PoE+

• Manage Ports using Power Priority and Power Budget

• Manage Legacy Devices

• Suspend Power Delivery on a Port

• Restore Power Delivery on a Port

• Display the Power Details

Power over Ethernet (PoE) 694