SLVSF02D March 2019 – May 2020 TPS23881
With the release of the IEEE 802.3bt standard, compliant PoE equipment has expanded to include four different "Types" of devices that support power over 2-Pair or 4-Pair, in either Single or Dual signature configurations, with classifications ranging from 0 to 8. Different manufactures have used varying terminology over time to describe their equipment capabilities, and it can become difficult to identify how to correctly categorize and brand a particular piece of equipment. For this reason and in conjunction with the Ethernet Alliance (EA), the industry leading providers of PoE equipment and devices have agreed to transition to using the "PoE 1" and "PoE 2" banding per the table below Table 1.
| Brand /
|IEEE Standard||Clause||Clause Title||Types||Classes||EA Certified Logo|
|PoE 1||802.3af||33||Power over Ethernet over 2-Pairs||1||0 - 3||Gen 1 Class 1-4|
|802.3at||2||0 - 4|
|PoE 2||802.3bt||145||Power over Ethernet||3||1 - 6, or 1-4 DS(1)||Gen 2 Class 1-8|
|4||7 - 8, or 5 DS(1)|
By design PoE 2 PSEs are fully interoperable with any existing PoE 1 equipment, and although not all functionality may be enabled, PoE 2 PDs connected to PoE 1 PSEs are required to limit their power consumption to the PSE presented power capabilities see Power Allocation and Power Demotion.