Things to Know About Power Over Ethernet Switch

Nowadays, with the rapid development of network technology, people need a network technology that can support data transmission and power supply. The invention of power over Ethernet switches brings people a lot of conveniences because of their flexibility and reliability. Power over Ethernet switches has been applied in many applications to keep the network at peak utilisation. So what is power over Ethernet switch and how does it work? This post will give you the answer.

What Is Power Over Ethernet Switch and How Does It Work?

The power over Ethernet switch is also called the PoE switch. PoE switch belongs to a network switch or hub, it can not only transmit network data but also supply power to connected devices over one Ethernet cable at the same time, which can greatly simplify the cabling process and cut costs. At the same time, PoE technology is applied in different devices, such as IP cameras, IP access points and voice-over IP (VoIP) phones.

When a PoE switch is connected to a PoE-Capable device, it can detect automatically the same devices that you have. Each of the spare wire pairs of the PoE switch is treated as a single conductor and the electricity is injected into the cable. And PoE switch can sometimes be transmitted on the data wires by applying a common-mode voltage to each pair. Because the twisted pair Ethernet cable uses differential signalling, the voltage doesn’t interfere with the data transmission.

Figure 1: How Does Power over Ethernet Switch Work?

Common Power Over Ethernet Types

According to different ports, power over Ethernet switches can be grouped into three common types, they are 8-port,24-port and 48-port power over Ethernet switches. Different types differ in switching capacity, price and other aspects. For example, different PoE switches have different switching capacities and prices in FS. Different types of PoE switches also have different applications.

Confusing Questions About Power Over Ethernet Switch

1. What are the differences between PoE switches and normal switches?

They differ in reliability, function, cost and manipulation. Compared with normal switches which only support data transmission, power over Ethernet switches can support data transmission and power supply. Devices connected with power over an Ethernet switch don’t need to perform power supply wiring, which can save costs and simplify the whole network management.

2. What are the differences between PoE and PoE+?

Firstly, one difference between PoE and PoE+ is the actual Institute of Electrical and Electronics Engineers (IEEE) standards themselves. PoE is 802.3af, while PoE+ is 802.3at. The maximum capacity of PoE can reach 25.5 w, while the maximum capacity of PoE+ can reach 35.4 w. Secondly, the maximum support current of PoE is 350mA, while PoE+ is 600mA.

3. Can I use PoE ports for non-PoE devices?

Yes, you can. All PoE switches have auto-sensing PoE ports, which means that the PoE port will detect if the connected device is a PoE device or not. But you need to cheque whether your PoE device supports 802.3af or 802.3at because non-standard PoE switches don’t have auto-sensing PoE ports, which is more likely to damage the network port.

4. Do all Ethernet cables support  PoE?

Yes, nearly all Ethernet cables support PoE. PoE will work with existing cable, including Category 5e, 6,6a or 7.


It is without that power over Ethernet switches that significantly improve the efficiency of network devices. After reading the whole passage, you may likely have a general idea of PoE switches. FS provides different types of PoE switches for Ethernet PoE power supply and data communication. For more information, just reach us via

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Gigabit PoE Switch vs Normal Switch

FS 24-Port PoE Switch for High-density PoE Installations

Due to the increased requirements for IP surveillance networks, the appearance of PoE switches gives you an easy way to add PoE devices to the network. They are ideal for small business networks that need to inexpensively use PoE to deploy wireless access points, IP phones and IP cameras. The PoE switch models are available with 4, 8, 16, 24 or 48 ports, although other variants are also available. 24 port PoE switch is the most prevalent variant on the market. So why does your network need a 24-port PoE switch and how can the network benefit from deploying it? This article explains it in detail.

Why Your Network Needs A 24-Port PoE Switch?

When choosing an Ethernet switch, the most important is to check whether the number of ports on the switch is enough to connect all your devices. The same is true when choosing PoE as a switch. PoE ports are flexible to connect with Cat5e cable without additional settings. Generally, the PoE switch has uplink ports, which allow long-distance data transmission between switches. Switches without uplink ports can still be linked together but you may experience bandwidth issues with switch-to-switch data flow. A 24-port PoE switch fully complies with the IEEE 802.3af standard for PoE up to 15.4W per port and the latest IEEE 802.3at standard for PoE+ up to 30W per port.

On the whole, the 24-port PoE switch can greatly reduce the associated cost with smaller PoE installations in a home or small business environment. At the same time, it will allow you to expand your network to areas with no power lines. Essentially, the plug-and-play PoE switch will automatically detect whether connected devices are PoE and send power accordingly. For a 24-port PoE-managed switch with a power budget of 370W, you need a total power per port of 30W to power an IP camera network. And you can continue to add IP cameras until you reach your budget. If you have 2 SFP ports, you can also connect to multiple switches. Keep in mind, that if you exceed the power threshold and the devices aren’t getting sufficient power, they may not boot up properly. Finally, please ensure you cheque the power requirement for your PoE-enabled device, the standard it complies with and the overall PoE budget of your installation before purchasing a 24-Port PoE switch.

FS S3400-24T4FP 24-Port PoE Managed Switch – 4 x 1Gb Combo Uplinks, 370W

FS S3400-24T4FP managed PoE switch comes with 24 10/100/1000Base-T RJ45 Ethernet ports, 1 console port, and 4 combo ports for fibre uplinks. It offers network managers the advantage of connecting up to 24 power-hungry wireless access points, IP security cameras, LED lighting or VoIP endpoints to the network with a single wire for power and connectivity. With its robust PoE power budget of 370W, the S3400-24T4FP switch supports denser deployment of PoE devices. This switch has a 56Gbps switching capacity with an 8K MAC address table. The power supply is supportive as well, which is about 100-240V. This is a solidly built excellent switch from the firm with a data transfer rate of 1,000 Mb/s. It represents an ideal switching solution for even advanced SMBs or entry-level enterprises which demand industrial, surveillance, IP Phone, IP Camera or Wireless APs. All in all, the PoE switch provides security, performance, quality of services, central management and other network control capabilities.

Key Features:
  • Up to 24 PoE+ Ports, Total Budget 370W
  • 3 Built-in Fans and Single Power Supply
  • Support ERPS, QoS, OSPF, L2 Multicast Functions, RIP
  • Support SSH, ACL, AAA, 802.1X, RADIUS, TACACS+, etc. for Security
  • Advanced Network Monitoring Using SFlow
  • Support WEB/CLI/SNMP/SSH for Flexible Operation


PoE switch is a cost-effective solution to increase the reliability and security of networks by providing centralized backup power to all connected IP surveillance devices. Before purchasing PoE switches, try to know as many details about the switch specifications as possible and also your own needs. FS S3400-24T4FP managed PoE switch is an affordable switch to support SMB switching needs for wireless converged networks and IP surveillance. If you prepare for growth and buy infrastructure for the long term, you will find this 370W PoE power budget provides headroom for future expansion.

Related Article: Deploying 48-Port Gigabit PoE Managed Switch in Different Networks