Which are the two standard types of PoE?

The correct choice identifies IEEE 802.3af and IEEE 802.3at as the two standard types of Power over Ethernet (PoE). IEEE 802.3af, established in 2003, is the original PoE standard, allowing for the delivery of up to 15.4 watts of power per port over Cat5 cabling. This standard significantly expanded the ability to power devices such as VoIP phones, access points, and cameras without needing separate power sources.

Following this, IEEE 802.3at, also known as PoE+, was introduced in 2009. This standard enhanced the earlier version by allowing a higher power output, providing up to 30 watts per port. The increased power capacity enables the support of more power-hungry devices, such as pan-tilt-zoom cameras and video phones.

The other options incorporate standards that are either not related to PoE or are not standard types related to Power over Ethernet. For example, IEEE 802.3bt, while relevant, is not mentioned in the correct choice and represents a newer standard that follows PoE+, allowing even more power delivery. Additionally, IEEE 802.3az refers to energy-efficient Ethernet, and both IEEE 802