Power Over Ethernet (PoE) is a technology that lets network cables carry electrical power to many different devices on a network.  With VoIP, utilizing PoE means phones have a single connection to a wall socket, and can be remotely powered down, just like with analog (PSTN) phones.
 PoE Diagram

Many phones are PoE ready right out of the box, but utilizing this feature will require a PoE Switch or Router that is capable of sending the power the devices need.

The following models support optional PoE:

  • IP331 - Polycom 2 - Line
  • IP335 - Polycom 2 - Line
  • IP550 - Polycom 4 - Line
  • IP650 - Polycom 6 - Line
  • VVX201 - Polycom 2 - Line
  • VVX310 - Polycom 6 - Line 
  • VVX410 - Polycom 12 - Line
  • VVX500 - Polycom 16 - Line Touchscreen
  • VVX600 - Polycom 20 - Line Touchscreen
  • SPA504G - Cisco 4 - Line
  • SPA525G2 - Cisco 5 - Line
  • IP20xx - Vertical 2 - Line

Using PoE with IP20xx - Vertical Phones:

•  To use a Vertical desk phone with PoE, move the power switch to the "POE" (down) position.
•  To use a Vertical desk phone with the power adapter, move the power switch to the "Adapter" (up) position.

Using PoE with Polycom Phones:

•  When a Polycom desk phone has a power adapter plugged in, it will not attempt to get power from the Ethernet cable. 
•  When a Polycom desk phone has only an Ethernet cable plugged in, it will attempt to get power from the Ethernet cable.
•  The Polycom phones auto-config to use the correct power level using 802.3af, which all unmanaged & managed switches support by default.

If your IT needs to manually configure the phones' power level with a managed switch, they may be able to configure this themselves.  Intermedia Voice Support cannot assist with manually setting the PoE power levels; however Polycom does offer an official PoE document that details Power Classification: Polycom's PoE PDF.