This article explains the fundamental concept of POE switch and its use. Different deployment scenarios where POE switches are used is explained in detail. The different types of POE switches and common FAQs related to POE switches are explained.
How does a POE switch work
POE stands for Power over ethernet. The switch ports on a normal ethernet switch can carry only data. When POE is implemented on switches, the ports on the switches would be able to carry both data and power. Devices connected to ports on the switches can be powered using the power transmitted from the switch port and would not require additional power supply units
This is achieved by sending power using the cable connecting the switch port to the device. The twisted pair cable would be able to carry both data and power.
What is the use of POE switch
A POE switch is used in deployment scenarios where power supply connections are unavailable. If designed properly , the use of POE switches can save a lot of power supply installations at the required locations.
We discuss three different deployment scenarios where POE switches are deployed on a network.
How is POE switch connected to a network
POE switches have up link ports on them in addition to the ports which are used to connect to the devices. The uplink ports are connected to the traditional switches on the network.
POE SWITCH DEPLOYMENT SCENARIO 1 – Security Camera
POE switches are used to deploy security cameras. Security cameras are installed at different locations in a building. This could be on the ceiling, corners, specific areas where power supply units are not available. The cameras connect to the POE switches, which would then supply the power.
POE SWITCH DEPLOYMENT SCENARIO 2 – Access point
POE switches are used to deploy access points. Access points like security cameras are also installed at various locations in a building.These locations are identified for the best wifi coverage. These locations may or may not have power supply. A POE switch is then used to power the access points at the different locations.
POE SWITCH DEPLOYMENT SCENARIO 3 – Voip Phones
POE switches are used to deploy Voip Phones. Voip phones are setup at respective desks. Voip phones typically have two ports. One port connect to the RJ 45 socket on the wall and the other to the PC. The socket on the wall would be connected to a POE switch, which would power the Voip phones.
How to setup a POE switch
Assuming that you already have a network setup and couple of access points and security cameras have to be deployed. The steps detailed below explain how to setup a POE switch.
Identify the number of devices which require POE connectivity. This is required, since , the POE switches comes in different variations like 8 port, 24 port, 48 port etc
Purchase the required POE switch. Connect the uplink of the POE switch to the switch port on the network.
Assuming that there is appropriate cabling laid to the points where the devices are setup, connect the respective ports on the POE switches to the patch panel ports where the cable termination from the devices is done. The cables used are normal ethernet cables.
The IP address for the devices are either setup manually or provided dynamically by a DHCP server on the network.
The above 4 steps would ensure that POE switch is setup properly.
What are the different types of POE switches
As with normal switches, POE switches also comes with a specified number of ports. POE switches comes as 8 port, 24 port, 48 port etc. Based on the number of devices which need connectivity, the appropriate switch can be purchased. The switches are also available as manged and unmanaged switches.
Managed switches have the capacity to be managed using IP address and you would also be able to perform configurations on them. Unmanaged switches cannot be managed and can only be used for generic POE function of transmitting data and power.
POE switch FAQs
1. What happens when a non poe device is connected to a POE switch port.
The switch port would detect if the device connected connected to it supports POE on its network adapter. If yes, it would supply power. If it does not, it would not supply the power and only data is transmitted. Nothing would happen to the device.
2. How do you connect a NON POE switch to a POE switch
POE switches have uplink ports on them which are used to connect to a NON POE switch.
3.Can POE switch be used as normal switches
Yes. They can be used as a normal switch. If the devices connected to the switch ports do not support POE, then it would only transfer data like a normal switch.
4.What type of cable should be used for connecting the POE switch ports to the devices.
Normal ethernet cables are used. POE is a ethernet standard. The power in this case is transmitted using two pairs of cables in the twisted ethernet pair.
5.What type of cable should be used for connecting the POE switch to a NON POE switch.
Normal ethernet cables are used. Note that if the up-link ports does not auto sense, you may need to use a cross over ethernet cable
6.What is the maximum distance a POE switch can power a device
Ethernet supports 90 meters. This is the maximum permissible distance between the POE switch port and the device which is connected to it.
7.Who are the different vendors which manufacture POE switches
Almost all known vendors manufacture POE switches. Some of the vendors which manufacture POE switches include netgear, TPLINK, Cisco etc.
8.Can POE switch of one vendor connect to a POE switch of another vendor
POE is a generic standard. There would not be any interoperability issues between POE switches from different vendors.