What is Power over Ethernet (PoE)?

Power over Ethernet (PoE) is technology that passes electric power and data over twisted-pair Ethernet cable to wireless access points, IP cameras, and VoIP phones. It enables one RJ45 patch cable to provide both a data connection and electric power to connected edge devices instead of having a separate cable for each. Read more about Power over Ethernet (PoE) here.

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What is x network switch?

A network switch is a hardware device that connects devices ("network clients") on a local area computer network.

It makes it possible for printers, PCs, wireless access points, and other network-capable devices to connect with one another.The Layer 2 switch is the type of network or Ethernet switch that is most frequently used.Any Layer-2 Ethernet switch that adheres to the OSI model employs MAC addresses to route traffic.In order to transmit communication exactly to the recipient's connected destination port, Layer 2 switches keep a MAC address table of all connected LAN clients.Due to the fact that they "know" which ports network devices are attached to, they differ from earlier, more basic devices known as network hubs.Incoming packets were instead sent to all ports by these hubs.

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What is a Power over Ethernet (PoE) Switch?

A PoE switch is a regular Fast Ethernet or Gigabit network switch that has Power over Ethernet functionality integrated. A Power over Ethernet switch both enables communication among network clients and provides power using the same RJ45 network cable to PoE-enabled edge devices, such as VoIP phones, network surveillance cameras or wireless access points. A PoE switch allows compatible devices to work in places where power outlets or network connections don't exist. This primary function of PoE can save businesses lots of money on the costs of installing electrical and network wiring (more on that below) while still having edge devices work where they are needed. PoE switches exist in many different variations.

PoE switches can be categorized by the following attributes:

Number of PoE-enabled ports:

PoE switches can provide anywhere from four to 48 PoE output ports, also called PSE (or "Power Sourcing Equipment") ports.

Network speed

Most common Power over Ethernet switches provide Gigabit speeds (1000 Mbps) to connected devices. However, Fast-Ethernet (100 Mbps) is still around, and for many PoE edge devices, that is plenty of speed.

Managed or Unmanaged

A managed PoE switch can accomplish much more than just routing data where it needs to go and powering devices in order to satisfy more complex network requirements. A managed PoE switch can group network traffic into segments and provide much more information on the status of the network, the connected clients, and its power status among its many other features and advantages.

LCD Display Option

Some unmanaged PoE switches have an LCD display on the front panel. These LCD status screens provide network admins with real-time power information, such as how much power each connected PoE device consumes, the combined used-power total of all connected devices and the total power available. It also very useful in giving alerts about potential problems and warnings for overload, high temperature, short-circuit protection and others.

PoE Budget

The ability of the Power over Ethernet switch to power connected devices is largely determined by the size of its power supply, which can range from just above 50 watts to well over 500 watts. This power budget directly affects how much power per port the switch can deliver to connected devices.

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What are the benefits of using a PoE Switch?

Installation Cost Savings

It costs a lot of money to bring standard power to locations where there is not any. For example, say you want to add cameras to the part of a warehouse that does not have power outlets. Without PoE, you would need to consult a certified electrician since a network administrator would very likely be unable to complete the electrical installation. However, with the low-voltage application of Power over Ethernet, anyone can run network cables (or PoE network cables) from the cameras to a PoE switch. Using PoE means you also avoid the need of installing power outlets, electrical wiring and breaker boxes, which saves even more money.

Greater Flexibility

PoE edge devices can be easily deployed in locations without power outlets. Since they no longer face the limit of needing a standard outlet to work, those previously hard to reach places can now be accessed with more ease. Installing a PoE network camera high up on the wall or the roof isn’t as daunting a task anymore since you only need one network cable to get power and network connections.

(Remote) Power Management

A very helpful feature of managed PoE switches is that you can access them over the Internet or local network. This access includes being able to remotely power-cycle edge devices that may have failed. The network camera that crashed or the VoIP phone that needs a reboot no longer needs physical intervention from a person on location. All that is needed for the required restart on either device is to initiate one via the switch management interface.

PoE Watch Dog / Guard / Powered Device Monitor

Some Managed Power over Ethernet Switches can monitor all connected PoE devices and automatically initiate the restart of a device that has failed to communicate for a defined period. Such a feature can be especially useful, for example, in case a security camera stops working in the middle of the night.