What is a PoE switch? How to use a PoE switch?

Aug 10 , 2024 253

A PoE switch, also known as Power over Ethernet (PoE), is an access layer technology. It is a technology that powers and transmits data to wireless access points, VoIP phones and IP cameras over twisted pair Ethernet cables. Its most important feature is that all devices can be powered by sharing the same Ethernet cable, instead of having to use a separate cable for each device, which not only saves costs, but also brings great convenience to administrators.

When it comes to the evolution of PoE switches, the development of Ethernet switches has gone through several key stages, starting with the earliest PoE (Power over Ethernet) standard.PoE initially provided limited power output for smaller network devices, such as IP phones and low-resolution cameras. As technology progressed, the PoE+ (IEEE 802.3at) standard was introduced, enabling switches to provide higher power, meeting the needs of a wider range of devices, such as high-resolution IP cameras and video phone systems. Further developments brought about the PoE++ (IEEE 802.3bt) standard, which provides up to 240 watts of power output for network devices for large wireless access points, high-definition video surveillance cameras, and other high-power devices.

The following table compares data between PoE switches, PoE+ switches, and PoE ++ switches:

Why use a PoE switch?

POE switches not only provide an efficient, flexible and economical solution, but also significantly enhance the management efficiency and operational stability of enterprise networks, making them an indispensable and important part of modern network architecture. The following are the main functions of POE switches:

Power over Ethernet: POE switches allow the transmission of data and power over a single Ethernet cable, eliminating the need for additional power wiring arrangements and making them suitable for remote or hard-to-reach device installation scenarios, such as surveillance cameras, wireless access points, and more.

Multi-port connectivity: POE switches typically provide multiple Ethernet ports, allowing multiple devices to connect to the network at the same time.

Increased security and reliability: POE switches support VLAN connections, allowing administrators to divide the network into multiple smaller networks, which can improve network security and reliability.

Flexible and Scalable: POE switches can be readily adjusted and relocated as needed without the need to rewire or add additional power devices. Ideal for offices, campus networks, and industrial control systems in dynamic environments.

Convenient manageability: Switches with integrated POE technology can monitor status by accessing signals, and are also able to share information with hand-powered devices via PoE switches for improved reliability and security.

Quality of Service Enhancement: POE switches are able to allocate bandwidth based on the priority order of traffic to ensure that major applications receive stable network resources.

When do I need to use a POE switch?

If you only have one or two devices that require PoE, you might consider using an injector to power them. These small devices plug in between the Ethernet switch and the devices that need power and are compliant with the IEEE 802.3af standard.

However, if you have a large number of PoE devices in your network, such as VoIP phones, using injectors alone can become cumbersome and complex. Ordinary switches usually do not support PoE, so it is not possible to use an injector to provide power before the switch.PoE switches are able to solve this problem, and it these switches provide a mix of active and passive ports, making them usable in your ordinary network.

Some of the more advanced models (such as those offered by Netgear) have an auto-sensing feature. This feature detects if a PoE device is connected to the port and automatically powers it up, while it will turn off power to non-PoE devices. This design ensures that you can safely connect any device to any port, avoiding the risk of device damage.

NetDirect Communications always strictly adheres to the high standard requirements of POE switches and provides customers with solutions that meet industry standards. This has led to constant praise from customers for the solutions designed by NetDirect Communications for POE switches. In order to meet the network construction needs of medium-sized and large enterprises, NetDirect Communications has continuously enhanced its professional reserves and hardware equipment support, and the existing hardware equipment inventory has reached 100 million pieces! There is a wealth of Cisco, Huawei, Huasan brand popular POE switches in large quantities in stock waiting for you to buy!

How does a PoE switch transmit data?

If say there are 5 printers in your LAN, and you want one of them to print information for you, how does your PC need to recognize and send data to this printer?

In fact, in LAN, each device has its own two addresses: MAC address and IP address.

The MAC address belongs to the layer 2 address. The manufacturer assigns a permanent MAC address at the time of manufacture, and this address cannot be changed under any circumstances. So that when different devices need to communicate on the same LAN, they will use the MAC address to do so.

IP addresses are Layer 3 addresses that can be selected by the network administrator. When devices need to communicate with each other, IP addresses are also used to fulfill our need to communicate with devices on different network segments.

POE switches are located at Layer 2 and need to use MAC addresses to transfer data between devices. When your printing request is sent to the POE switch, it automatically recognizes it and helps you send the message to a specific printer for operation.

Overall, POE switches not only improve network flexibility and efficiency and reduce costs, but also support the needs of a wide range of application scenarios and lay the foundation for future network technology development. In today's wave of digital transformation, network architecture with POE technology has become one of the key factors to enhance business competitiveness and innovation.