WAX214v2 not detecting POE AT

---

Forerunner225 wrote:

POE+ unmanaged switch by Steamemo. The switch supports 802.3AF/AT.  It is the 6Gb 52W 4xPOE+ switch. ,,, My switch is a POE+ AT switch with up to 52w max power to the device. 

---

Let's break down the marketing nonsense:

Total internal switch capacity might be 6 GbE, all ports are 1 GbE, and the PoE can provide a max total of 52W - on all PoP ports.

802.3af does specify 12.95W at the PD, 15.4W at the PSE 802.3at does specify 30W at the PSE, with max. 25.5W available at the PD.

For 802.3at, there is a two-event classification Sequence before power-down:

The first handshake. The PSE detects a connected PD by sending a short low-voltage pulse which determines how much power the PD needs. This pulse is unlikely to damage a non-PoE device. Depending on how much current it draws during this pulse, the PSE classifies the PD into one of classes 0-4 (0-3 / type 1 PSEs and PDs).

PoE step down classifications

The second handshake is required for a type 2 PSE to classify the connected PD into class 4 (PoE+ power), informing the PD that full 802.3at power is available.

==>> Here something goes wrong in your deployment!

The PSE now has confirmation that a type 2 PD connection took place to the port, ensuring that the PD device is secure from a power burst. Before this second handshake takes place, the PD and PSE restrict power to within 802.3af limits.

This second handshake takes one of two forms:

• a hardware-based two-event classification
• a software-based LLDP classification

The 802.3at standard mandates that PSEs support only one of these mechanisms. PDs, however, must support both classification methods to ensure the capability to join a variety of networks.

==>> Similar to the Netgear unmanaged PoE, PoE+, and PoE++ switches, there is no information available on the effective negotiation status.

To the Netgear WAX214v2, only 802.3af can be negotiated. But you already know this.