About Poe - NETGEAR M6100 Series Reference Manual

About PoE

Power over Ethernet (PoE) describes a technology to pass electrical power safely along with
data on existing Ethernet cabling. The power supply equipment (PSE) is the device or switch
that delivers electrical power, and the PD or powered device is the end device that powers up
through the power delivered along the Ethernet cable.
The NETGEAR Managed Switch software supports PoE, PoE+, and UPoE as follows:
• PoE (802.3af 2003). This is the original standard, also known as the low-power standard,
which mandates delivery of up to 15.4 watts by the PSE. Because of power dissipation,
only 12.95 watts are assured to be available at the powered device (PD). The PD needs
to be designed so that it can accept power over Ethernet cabling. Category 3 cables can
be used to deliver power to the PD. However, with the advent of 802.11n, the newer
wireless APs required more power. To account for this, a newer standard was developed
in 2009, known as 802.3at.
• PoE+ (802.3at-2009). This is a newer standard than PoE. This is also known as the
high-power standard, which mandates delivery of up to 34.2 watts by the PSE. Because
of power dissipation, PoE+ provides only a maximum of 25.5 watts at the powered
device. Some PSEs can provide up to 51 watts. Before this standard became available in
2009, the industry started using different implementations to allow for more power. All
these needed to be brought under the purview of the newer 802.3at standard.
UPoE. Universal Power over Ethernet (UPoE) extends PoE+ to deliver up to 60W. For a
•
48-port switch, UPoE can provide a total of 2,880 watts power budget for all ports. UPoE
delivers the power over a spare pair or Alternate B pair (4,5 and 7,8) simultaneously
along with the data pair or Alternate A pair (1,2 and 3,6). Power beyond 30 watts is
always delivered using the data and spare pair. UPoE provides two options for enabling
the spare pair: LLDP, which is the preferred method, and forced UPoE. UPoE also
supports green modes of operation.
Note: UPoE is supported only on the XCM89UP.
Note: PoE, PoE+, and UPoE are supported only on physical, copper
interfaces. The default port mode is PoE+.
M6100 Series Switches
Power over Ethernet Commands
1142