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What are the differences between non-PoE, PoE, and PoE+?

non-PoE switch is a switch that provides network connectivity only, and does not supply DC power to connected devices. These switches are suitable when there are a large number of non-powered network devices on the network, such as PCs and laptops. Such switches are commonly deployed in offices, as well as in hotels, student housing, assisted living, and other multi-dwelling unit (MDU) environments where there is a wired Ethernet wall jack in each unit.

Power-over-Ethernet (PoE) switches provide both DC power and data connectivity over a single Ethernet wire. These are extremely useful for connecting powered network devices to a network, as only one cable needs to be run to the device, as opposed to separate cables for data and for power. Per the IEEE standards, switches are able to detect whether a connected device is powered or not, and will therefore only provide power to devices that are not being powered by an alternate power connection. When using managed Power-over-Ethernet switches, the connected device can also be rebooted remotely by turning off and on the power on the Ethernet port, which is very useful when doing network troubleshooting.

PoE switch conforms to the IEEE 802.3af standard, which provides 48V up to 15.4 W per port. PoE (802.3af) is sufficient for powering older generation access points (i.e. pre-802.11ac) and for most other powered network devices, such as IP cameras, VoIP phones, access control locks, etc.

PoE+ switch conforms to the IEEE 802.3at standard, which provides 48V up to 30 W per port. PoE+ (802.3at) is required for 802.11ac access points because of the large number of radio chains required for MIMO and MU-MIMO.

It is best practice to not fully load a PoE (802.3af) or PoE+ (802.3at) switch, to ensure that the total power budget of the switch is not exceeded. EnGenius generally recommends a “3/4 rule”, meaning that a network design should plan on only using ¾ of the ports for powered network devices, as follows, with remaining ports being reserved for non-powered network devices, backhaul to other infrastructure (e.g. other switches or routers), or spares:

  • 8 port PoE/PoE+: Only 6 ports should be used for powered network devices

  • 24 port PoE+: Only 18 ports should be used for powered network devices

  • 48 port PoE+: Only 36 ports should be used for powered network devices

Most PoE and PoE+ switch models come with some non-PoE ports for backhaul, consisting of either Ethernet ports and/or SFP ports (for mini-GBIC fiber modules). On EnGenius switches, any standard third party SFP module (1 Gbps) can be used. For a detailed explanation of SFP modules, please read the blog.


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