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PoE vs. AC Power

By: Amanda Easter

What is Power over Ethernet or PoE and do I need an AC power supply for my phone?

PoE technology is a system that sends power over the Ethernet cabling to an endpoint such as a PoE-enabled phone, IP camera, or wireless access point. The power that is sent over the Ethernet cabling originates from either a PoE switch or a PoE injector. If you do not have a PoE switch or a PoE injector, an AC adapter will need to be used to power the phone.

How do I know if I have a PoE switch?

To find out if you have a PoE switch you will need to pull up the technical specifications on the switch, which can be done by going to the manufacturers website or doing a search on the internet for the technical specifications. Once you have found the technical specs, in the description about the switch it may say that it supports “IEEE802.3af standard for Power over Ethernet” which is what you are looking for. Otherwise, under Expansion / Connectivity in the tech specs it will say the number of ports that are PoE if any e.g. 24 X network / power.

So what are the benefits of using PoE instead of AC adapters?

Lower cost – There is no need for an AC outlet at the location of the endpoint (phone, access point, camera) which may get rid of or limit the need to have an electrician install an AC outlet(s).

Less cables – Not needing an AC adapter is one less cable to deal with which helps to provide a more “professional look.”

Enables centralized power – In the event of a power outage, IP phones will lose power if they are plugged into a wall outlet. Powering the endpoints via a POE switch allows for centralized power where the PoE switch can be plugged into an uninterruptible power supply (UPS).