PoE (Power over Ethernet) is a technology for supplying power to a client device through a twisted-pair cable of the gigabit ethernet standard (usually a cat.5 cable with RJ45 connectors is used). The same cable is used both for data transmission and for powering the device.
What Devices Does It Support
As power devices can be:
- and other network equipment.
As client devices can be used:
- corded phones
- access points
- various sensors and other peripheral equipment.
What Is POE Used For?
The following are the benefits of using this technology.
Connecting devices in hard to reach places
For example, at the user’s workplace, only two sockets are provided: for a monitor and a system unit. Often, such requirements do not arise due to an error in planning, but are dictated by industry, regional and other standards of IT security, fire safety, labor protection and so on.
Another example is if the camcorder or access point is fixed under the ceiling, it can be difficult to extend the power cord there.
Disadvantages Of PoE?
Higher device cost
Indeed, it costs more. Especially if you take more or less proven equipment, and not rely on “maybe”, buying “inexpensive NoName solutions.”
On the other hand, the “more expensive means better” principle does not always work. Therefore, hunting for an expensive brand makes sense only if there are additional requirements (there is a list of “authorized equipment”).
But even with the high price of equipment with PoE, its price can be much lower than the organization from scratch of an additional branched cable system for powering remote devices.
When transmitting a low-voltage signal through thin wires, the efficiency, let’s say, will not be very. The farther from the supply device, the less electric power will remain to power consumers. The rest is spent on resistance and heating wires. Local power (non-PoE) is easier.