Power Over Ethernet - Dell Force10 C150 Configuration Manual

Power over Ethernet

Power over Ethernet
This chapter contains the following major sections:
• Configuring Power over Ethernet on page 786
• Power Additional PoE Ports on the S-Series on page 794
• Deploying VOIP on page 795
FTOS supports Power over Ethernet (PoE), as described by IEEE 802.3af . 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.
Table 36-2 describes the classes of powered devices defined by IEEE 802.3af:
Table 36-1. PoE Classes of Powered Devices
Class
0
1
2
3
4
Note: FTOS treats Class 0, Class 3, and Class 4 powered devices the same. Class 4 is meant for
IEEE802.3at compliant devices which require >12.95 Watts. Currently FTOS treats Class 4 devices as
Class 3.
FTOS supports PoE on all copper ports on the C-Series and on the S25V and S50V models of the S-Series.
The C-Series and S-Series transmit power to connected IEEE 802.3af-compliant powered devices through
ports that have been configured to supply PoE. Those platforms also support the protocols LLDP and
LLDP-MED, which help optimize power distribution to PoE devices. See
Discovery Protocol, on page
(PoE) is supported only on platforms:
Power Range
(Watts)
0.44 to 12.95
0.44 to 3.84
3.84 to 6.49
6.49 to 12.95
Reserved
861.
c s
Classification
Current
(mA)
< 5.0
10.5
18.5
28
40
36
Chapter 46, Link Layer
Power over Ethernet | 785