Ruijie RG-S2900G-E Series - Configuring Poe

Configuration Guide Configuring PoE Configuration
Protocols and Specifications
Currently, IEEE 802.3af and IEEE 802.3at provide two PoE standards. The following table lists the major features of the
two standards and their differences:
Parameter
802.3af
802.3at
Available PD power
12.95 W
25.50 W
Maximum power provided by the PSE
15.4 W
30 W
PSE voltage range
44.0–57.0 V
50.0–57.0 V
PD voltage range
37.0–57.0 V
42.5–57.0 V
Maximum network cable impedance
20 Ω
12.5 Ω
Power management mode
Power classes are defined during line
initialization.
Power is classified into four classes
during line initialization or dynamically
adjusted in steps of 0.1 W.
Types of cables supported
Category 3 or 5 twisted pair
Category 5 twisted pair
 According to IEEE 802.3af, a PoE switch can supply power over the idle line or signal line of a twisted pair whereas a
PD must simultaneously support power supply over the idle line and power supply over the signal line. Some Ruijie
PoE switches supply power over the idle line and the others supply power over the signal line. For details, see
related product specification documents.
 IEEE 802.3at switches provide downward compatibility. PoE switches that support 802.3at are also compatible with
PDs that only support IEEE 802.3af.
Configuring PoE
Setting the PoE Function on a Port
You can enable or disable the PoE function on a port. By default, the PoE function is enabled on the ports of access and
convergence switches but disabled on core switches. To enable or disable the PoE function on a switch, run the following
commands in the interface configuration mode: