Introduction to PoE
PoE technology allows IP telephones, wireless LAN access points, and other appliances to receive power and
transfer data over existing ethernet LAN cabling. For more information about PoE technology, see the
PoE/PoE+
planning and implementation guide
, which is available on the Networking website at
. Enter your Switch number.
Additionally, PoE+ provides more power-management capability, allowing the switch to have more power
available for more PDs. Power can be allocated exactly and automatically according to what the PD actually
requires at a given time.
PoE terminology
PoE and PoE+ operate similarly in most cases. Any differences between PoE and PoE+ operation are noted;
otherwise, the term "PoE" is used to designate both PoE and PoE+ functionality.
Planning and implementing a PoE configuration
This section provides an overview of some considerations for planning a PoE application. For additional
information on this topic, refer to the PoE/PoE+ planning and implementation guide which is available on the
Networking web site at
.
Some of the elements you may want to consider for a PoE installation include:
• Port assignments to VLANs
• Use of security features
• Power requirements
This section can help you to plan your PoE installation. If you use multiple VLANs in your network, or if you have
concerns about network security, you should read the first two topics. If your PoE installation comes close to (or is
likely to exceed) the system’s ability to supply power to all devices that may request it, then you should also read
the third topic. (If it is unlikely that your installation will even approach a full utilization of the PoE power available,
then you may find it unnecessary to spend much time on calculating PoE power scenarios.)
Power requirements
To get the best PoE performance, you should provide enough PoE power to exceed the maximum amount of
power that is needed by all the PDs that are being used.
By connecting an external power supply you can optionally provision more PoE wattage per port and or supply
the switch with redundant 12V power to operate should an internal power supply fail.
See the PoE/PoE+ planning and implementation guide for detailed information about the PoE/PoE+ power
requirements for your switch.
Assigning PoE ports to VLANs
If your network includes VLANs, you may want to assign various PoE-configured ports to specific VLANs. For
example, if you are using PoE telephones in your network, you may want to assign ports used for telephone
access to a VLAN reserved for telephone traffic.
Chapter 4
Power Over Ethernet (PoE/PoE+) Operation
106
Aruba 2930F / 2930M Management and Configuration Guide
for ArubaOS-Switch 16.08
